Controls quality

Quality control involves several subjects that must be discussed in connection with dry chemistry. It is the aim of all quality control methods that all results supplied by the clinical laboratory representing a useful estimation of actual data should approximate these actual data as closely as possible and with a low scatter. Quality assurance is subdivided into internal and external quality control. Internal quality control should accompany each series of examinations even if there is only one sample to be examined. In addition, external quality control serves to examine the precision and accuracy of a laboratory as compared to other laboratories. Any external quality control without internal quality control is meaningless. 

In the case of reagents bound to carriers, permanent internal and periodically external quality control will partly result in problems. The reasons for some of these difficulties may be ascribed to the matrix of the control material employed. Since additions of synthetic or animal substances are incorporated in almost all control areas, these are not directly comparable with human material. This is the crux of the problem in dry chemistry. Excellent agreement is usually found to wet chemistry when comparing patients samples, whereas control sera can yield great differences. The use of whole blood (Reflotron) as control material is particularly problematic. This involves problems of stability, so that in such cases only so-called tertiary standards can be used, thus essentially limiting the accuracy. 

This naturally raises the demand for appropriate control material. Control fluids of human origin would of course be the best solution, but this resort is hardly feasible because it involves formidable problems ranging from ethics to 

No final answer can be given to this question, for similar cases are also known in wet chemistry (for example, the Pack Analyzer ACA of DuPont de Nemours). Here, too, the apparatus or method is calibrated once for every batch and is rechecked daily or at regular intervals by means of the quality control sample. The system of dry chemistry can be viewed under the same aspect. The Ektachem system is known to be stable for more than 6 months, so that the apparatus or method need not be readjusted during this period but only supervised via quality control checks. The problem of calibration does not arise with Reflotron, since all the requisite data (calibration data) are stored on the reverse of the test slides. No data, however, are available on long-term studies of stability. The FDA has prescribed a 7-day or 30-day calibration rhythm for the Seralyzer system depending on the analyte to be analysed. 

Rigid process controls insure that each batch of bonded joints receives proper processing during the surface preparation, fabrication, and cure processes. Surface preparation processes are controlled with respect to 

During quality control the finished casting is checked for compliance with the product requirements concerning e.g. dimensions, metal structure defects, surface structure. Depending on die type of casting and the size of the series, quality control can be achieved by visual inspection, with the use of measurement tools, or automatically. 

In die production of aluminium wheels the castings are controlled via X-ray analysis. A standard image of a good casting is used for verification by a computer program. If diere are any differences, the image is studied and assessed by a human operator. Random tests of the alloy are analysed with spectral analysis. 

The quality control procedure informs the final decision to reject a casting or to allow its further shipment to the market. Rejected castings are brought back to the raw material input to be remelted. 

The following quality control methods can be adopted for assessing the radiochemical purity of the preparations. 

Solid phase separation using SepPak CIS cartridges 

The SepPak CIS cartridges are pre-conditioned with 5 mL of ethanol followed by 5 mL of 0.05M phosphate buffer at pH7.5. An aliquot of the labelled peptide mixed with 10 pL of 50mM DTPA is loaded on the cartridge. The unbound activities ( Lu) are eluted with 5 mL of phosphate buffer. The labelled peptide is then eluted with 3 mL of ethanol. The pooled fractions are counted separately, and the radiochemical yield is estimated based on the ratio of peptide fraction to the total activity eluted. 

Thin layer chromatography studies are carried out on silica gel (aluminium sheets, Merck) in 10 cm strips as the stationary phase. Ammonium hydroxide methanol water (1 5 10) is used as the mobile phase. While the free activity remains at the point of origin (R(= 0), the radiolabelled peptide migrates to an of 0.4. 

The HVAC system covering this area is controlled by air handling unit (AHU) No. 

Many laboratories operate quality control (QC) procedures to underpin sample preparation methods. Laboratories processing large numbers of relatively uniform samples, as in a production line environment, or research laboratories processing a smaller number of samples with varied matrices, have effectively the 

The application of appropriate Quality Control (QC) procedures or criteria is a mandatory consideration in the deployment and analysis of SPMDs (e.g.. Petty et al., 2000a). Similar to any performance-based methodology or approach. 

For projects needing stringent QC, control charts are recommended to monitor analyte recoveries throughout an investigation (see Taylor, 1987, for a detailed discussion). Briefly, during each quarter of a project, the last 20 observations of recoveries from QC spikes are used to generate a control chart. Control limits are established for the analytical process as described by Taylor (1987). When control limits are exceeded, sample analyses are suspended until the problem step(s) can be identified and corrected. These actions must follow an appropriate protocol for corrective action. The results of this type of investigation or procedure modification become a part of the permanent record of the sample set and the project. 

Herein, we describe the basic QC samples and parameters related to the performance of SPMD studies, and elucidate their role in conducting smdies. Also, a general overview of SPMD analytical procedures and data applicability are given. 

This type of QC blank consists of a batch or subset of individual SPMDs of the same size and material as those prepared for a specific project. After preparation, SPMD-fabrication blanks are maintained frozen in vapor-tight metal cans under argon at -10 to -20 °C in the laboratory until the analysis of the project SPMDs. Processing and analysis of these blanks is concurrent with and identical to that of environmentally exposed SPMDs. The primary purpose of this type of QC sample is to account for any background contribution due to interferences from SPMD components, and for contamination incurred during laboratory storage, processing, and analytical procedures. 

This type of QC blank consists of a subset of SPMDs, made just prior to initiation of the analysis of an SPMD sample set. Operationally, the only difference between SPMD-process blanks and SPMD-fabrication blanks is the time of preparation and that the SPMD-process blanks are not subjected to storage, but are immediately processed and analyzed along with the environmentally exposed 

This section presents some basic quality control procedures for the manufacturing process of pultruded advanced composites. The following three aspects of quality control are addressed  

Quality control procedures during execution on site are not covered. 

Incoming raw materials, specifically the matrix constituents and the fibre rovings and mats, should be inspected. Basic inspection includes checking the delivery notes and the labels of containers when the materials arrive. Visual inspection of raw materials is also recommended resins can be inspected for colour and the presence of contamination and gel particles (Evans, 2000) reinforcements can be checked for the presence of knots in the rovings, while simple mass measurements can be made for mats or fabrics. Some pultrusion companies have quality control and/or research and development laboratories where material characterisation tests can be performed (most often such control is executed by raw material suppliers). Fibre reinforcements can be subjected to tensile tests. The moisture content of the constituents (particularly the reinforcements and the fillers) can also be determined. The quality of incoming resins can be tested by means of thermal analysers (resin reactivity) and viscometers (resin viscosity and thixotropic index) (Owens Coming, 2003). 

Several pultmsion companies use Barcol hardness testers to assess the degree of cure of the produced parts. This enables the tracing of products with insufficient degree of cure of the resin matrix, which leads to lower mechanical performance. The quality control of pultruded produced parts can also include other mechanical characterisation tests which can sometimes be carried out in the laboratory facilities of pultrusion companies. EN 13706-3 (CEN, 2002) defines two grades of FRP pultruded profiles, specifying minimum values for material properties and the relevant test methods. The requirements for certain applications (e.g. petroleum and natural gas industries) can be stricter and often include aspects related to fire reaction and fire resistance behaviour, e.g. NBR 15708-1 (ABNT, 2011). 

The quality of the analytical work cannot be maintained without adequate quality control (QC) procedures. The meaning of the term quality control often varies according to context. In general QC is the overall system of activities used to fulfill requirements for documentation of quality. The system should be satisfactory, adequate, dependable, and economic. Examples of quality control are control charts, blank determination, blind samples, and repetitive determinations. The number of test results to be obtained from the analysis of each sample is related to the purpose of the analytical work. As guidance for QC purposes, it is necessary to analyze at least one sample in duplicate in every 10 determinations of the analyte. 

Control charts are the basic tools for QC providing the graphic means to diagnose measurement problems and to document that the precision and the trueness of the analytical method, established in a method evaluation study, stay acceptable during long periods of time [5,12]. Control charts can also be used to document the quality of sampling operations. The most commonly used control 

It is assumed that the method is in statistical control. This assumption is tested by measuring control samples and plotting the results in a Shewhart control chart in the order of appearance. The results are accepted if situated between statistically defined control limits [5,19]. If they are outside the control limits, the method is suspected to be out of control. The cause should be identified and corrected to reestablish control before measurements are continued. 

In principle all control charts contain a center line and control chart limits arranged symmetrically around and parallel with the center line. The center line represents the target value, which the control measurements in average should hit, when the method is in statistical control. It is important to know to what extent a reliable estimate of the long-term standard deviation can be considered known, i.e., o-y = o-y. 

Basically, two different control charts exist utilizing a single measurement or the mean of several measurements, the last mentioned being preferable because it is less sensitive to blunders. Duplicate measurements of a control sample permit the maintenance of control charts both for the mean of two measurements, and for estimation of the precision, based on the range of measurement (chart). 

There are a number of critical aspects in Quality Control (QC) of flavourings  

In contrast, under appropriate conditions, sensory analysis or sensory quality testing of flavourings is  

These modalities include other senses which are also very important for Sensory, such as sense of temperature and sense of pain. All these senses resp. modalities are important for quality testing of flavourings. Before we give a brief outline of them, various terms need to be defined, i.e. 

Relating to an attribute or a property of a sample perceived by the sense organs. 

A degustation is an act(ion) of gustation organoleptically. (In sensory nowadays organoleptic is normally an obsolete term because of confusion with sensory) 

Ideally, greater than 80-90% of the actin filaments should be moving in a constant manner at any time. Poor quality of movement is characterized by filaments that remain attached and do not move at all and by filaments that move erratically in a stop-and-go manner. In addition, shearing of the actin filaments is sometimes a problem. The probable factor underlying poor-quality movement is the presence of damaged or rigorlike myosin heads that bind to actin in an ATP-independent manner. The use of old nitrocellulose-coated surfaces may also contribute to this phenomenon. 

The most important determinant of the quality of movement is the use of fresh, pure myosin. Freshly purified smooth muscle myosin, stored in 1-5 mM DTT, typically exhibits good-quality movement for up to 10 days. Myosin can also be quick frozen in small aliquots (0.1-0.5 ml) and stored for extended periods of time in liquid nitrogen with good results. The myo- 

Several tricks can be used to improve the quality of movement in the assay. One is to apply 2-3 vol of buffer A containing 5 pM of unlabeled actin and 1 mM ATP prior to step 4. After 1-2 min of incubation, the flow cell is washed with buffer A and then rhodamine phalloidin actin is applied as in step 4. This treatment appears to tie up the rigor heads with unlabeled (and therefore invisible) actin. The other treatment is to mix the myosin in buffer B prior to the start of an assay with a stoichiometric amount of actin in the presence of 5 mM MgCl2 and 5 mM ATP, followed by centrifugation in a TLIOO ultracentrigue for 10 min at 100,000g, which will pellet the actin and attached rigorlike heads, but leave active myosin in the supernatant. Finally, the inclusion of tropomyosin (40-100 nM) in the motility buffer increases not only the rate of movement but also the quality of movement (Umemoto and Sellers, 1990). 

High quality is one of the criteria defined in the requirements section above. Since the program should run automatically in batch mode, we mean by quality control an internal check of the 3D structures produced by the structure generator itself. In general, the abilities of a fast, automatic structure builder to assess the quaUty of its models are rather limited since, for example, an exhaustive conformation analysis and energy optimization is impossible in most cases. However, there are a Umited number of simple quaUty checks to avoid trivially distorted structures  

If the above sketched quality checks flag for an unacceptably distorted or unrealistic geometry and the program cannot remedy this, it should be good practice not to send the questionable structure to the output file. 

It is self evident that mistakes in manufacture could result in premature failure of the product and consequently quality control in some form is essential. Unfortunately, case histories show that sensible control precautions are not always applied and in some instances appear to be totally absent. There are examples of inadequate control at all stages from checking of incoming materials, through lack of testing of the product to incorrect installation. 

As one illustration of quality control lapses causing failure, nitrile/PVC hoses analysed by the author failed from ozone cracking. Although suitably formulated, there had been a processing error and because the quality assurance (QA) testing for ozone resistance had not been carried out this went undetected. For this case, there was in theory a control procedure which is one stage better than no provisions for control, although the result was the same. 

One way in which break down of quality control occurs is through misunderstanding of who is controlling a material, the suppher or the purchaser. In this and other aspects of quality control it would be hoped that the very widespread adoption of accreditation to ISO 9000 standards will have lead to a general improvement in the rubber industry. 

There are also many papers considering methodology for prediction of lifetime from accelerated tests (for example (50, 61, 62) and this has been considered comprehensively in a guide to lifetime prediction (17). Stevenson (54) refers to costly mistakes having been made in critical offshore applications, from which the appropriate lessons have not always been learned, and considers some of the applications and the material evaluation requirements. 

A less common use of accelerated tests is to estimate remaining lifetime. Heat ageing of two compounds and applying the time temperature superposition principle and models based on Miner s rule of cumulative material damage is described by Gillen and Cehna (41). However, Sun and co-workers (50) found that Miner s rule did not apply for fatigue of black filled NR and SBR. 

In the above section, requirements for compounding of PET radiopharmaceuticals have been presented. In this section, the methods of quality control tests for these products are briefly described below. Since PET radiopharmaceuticals are short-lived, some lengthy tests cannot be performed prior to release for human use and so they are performed within a short time after the release. 

The quality control tests can be divided into two categories physicochemical tests and biological tests. Refer to Saha (2004) for detailed description of these methods. These tests are briefly outlined below. 

Physicochemical Tests Physicochemical tests include the tests for the physical and chemical parameters of a PET radiopharmaceutical, namely physical appearance, isotonicity, pH, radionuclidic purity, chemical purity, and radiochemical purity. 

Physical appearance. Physical appearance relates to the color, clarity, or turbidity of a PET radiopharmaceutical and should be checked by visual inspection of the sample. 

Isotonicity. Isotonicity is the ionic strength of a solution, which is mainly adjusted by adding appropriate electrolytes. Normally PET radiopharmaceuticals have appropriate isotonicity for human administration. 

CRM for road dust (BCR-723) containing 81.3 2.5 Jg/kg Pt, 6.1 1.9 ig/ kg Pd, and 12.8 1.3 Jg/kg Rh, was introduced [49, 228]. It is widely used for quality control of results obtained in the analysis of environmental materials (e.g., airborne particulate matters, dusts, soils, and sediments). Comparison of results obtained using different analytical procedures and interlaboratory studies are recommended when there is a lack of suitable CRM (e.g., in examination of clinical samples). The use of standards based on real matrices (e.g., saliva, plasma, ultrafiltrates, and lung fluids) instead of synthetic solutions is recommended in such analyses. Difficulties with the identification and quantification of different metal species in examined samples make the reliability of results of great importance. The use of various instrumental techniques for examination of particular samples can be helpful. The application of chromatography, mass spectrometry, and electrochemistry [199] HPLC ICP MS and HPLC MS/MS [156] ESI MS and MALDI [162] micellar electrokinetic chromatography, NMR, and MS [167] AAS, ESI MS, and CD spectroscopy [179] SEC IC ICP MS and EC ESI MS [180] and NMR and HPLC [229] are examples of such approaches. 

Acknowledgements Financial support of the work by the Warsaw University of Technology is kindly acknowledged. 

Platinum 2013 Interim Review, Johnson Matthey PLC, England 

Sobrova, P., Zehnafek, J., Vojtech, A., Beklova, M., Kizek, R. The effects on soil/water/ plant/animal systems by platinum group elements. Cent. Eur. J. Chem. 10,1369-1382 (2012) 

Rosner, G., Kdnig, H.P., Coenen-Stass, D., WHO Platinum. Environmental Health Criteria Series, No. 125. International Programme on Chemical Safety. WHO, Geneva (1991) 

The mass-scale production of PLA is most commonly used to make domestic consumer products, such as packaging or bottles, which come into contact with food. For these PLA products quality control no longer limits mechanical properties, as it does for commodity polymers (polyethylene, polypropylene, polystyrene, etc.). However, manufacturers need to carefully classify the extent of lactide, and specifically D-lactic acid, in the final product NatureWorks , as the largest producer of PLA, has set up standard testing procedures for the firms that produce items 

Step 2 Copolymerization of lactide, and poly(p-dioxanone) homopolymer and p-dioxanone monomer to form segmented copolymer 

Poly(p-dioxanone-co-lactide) segmented copolymers m p, and the poly(p-dioxanone) portion 70-98 wt % 

The determination of lactide composition in PLA is conducted by gas chromatography (GC) using a flame ionization detector (FID). This GC/FID method is only able to detect residual lactide in the range 0.1—5 wt%. Although the detection range is narrow, it is still within the concentration 3 wt% of lactide monomer found in PLA at 180°C, as well as after the devolatilization of PLA, when the concentration can further reduce to 0.3 wt%. As mentioned before, the lactide monomer consists of three stereoisomers — L-lactide, D-lactide and 

Internal standard stock Solution is prepared by adding 2,6- 

When the analytical method has been validated for routine use, its accuracy and precision should be controlled regularly to ensure that the method continues to work satisfactorily. For this purpose, a number of separately prepared (from different weightings than the ones used for the standard curve) quality control (QC) samples should be analyzed in each run [16], The QC samples are often duplicates at three concentrations (low, medium and high) within the range. At least four of the six QC samples should be within 20% of there respectively nominal value, and at least one at each concentration level [16, 89], Also a standard curve should be processed during each run [89], 

AH injectable solutions are tested for sterility and absence of pyrogens. Various chromatographic techniques, such as high performance liquid chromatography (HPLC), and other analytical techniques are used in the quality control laboratory to determine the purity and the amount of active drug present in the different dosage forms. 

Thayer, A. M., Pharmaceuticals Redesigning R D, Chemical Engineering News, 76(8), 25-37, 1998. 

Gadamasetti, K. G. Process Chemistry in the Pharmaceutical Industry, Marcel Dekker, New York, N.Y., 3-17, 1999. 

World Medical Association Declaration of Helsinki, Ethical Principals of Medical Research Involving Human Subjects, accepted on June 1963, latest amendment 2002. Available at www.wma.net/e/policy/b3.htm. 

Graham, P. L., An Introduction to Medicinal Chemistry, Oxford University Press, New York, N.Y, 246, 1995. 

QC on Ready-for-Use Products from a Manufacturer. These radiopharmaceuticals are to be administrated to the patient without further preparation. As the manufacturing is inspected by competent authorities in order to ensure a high quality of the production process, the QC in the hospital in most cases can be reduced to control of transport documents, labels, and radioactivity. Tests on radionuclidic or radiochemical purity are normally not required. 

QC on Products Intended to be Prepared in the Hospital. For these radiopharmaceuticals, the responsibility for the product is shared by the manufacturer(s) of starting materials and the hospital, where the radiopharmaceutical is prepared. 

Before approval of marketing authorization, an applicant must prove that, when prepared in a hospital, the margins between an acceptable and an imacceptable radiopharmaceutical are broad enough to permit great variations between preparation routines in different hospitals and variations between different operators performing the work. If the margins are too narrow, the prodnct is not likely to be approved, nnless the medical benefit ontweighs the efforts spent on QC of each preparation before its administration to the patient. 

In most cases, QC on each prepared radiopharmacentical is not necessary, except the control of radioactivity. On the other hand, QC of prepared radiopharmacenticals shonld be a part of the hospital s validation of rontines and working standards of personnel. 

QC methods that are intended to be used in hospitals must be simple, robust, and validated. Furthermore, control methods on radiochemical purity, which is the most common parameter, should easily demonstrate the radiochemical purity. It is seldom necessary to know the precise percentage of every single impurity. 

Because sampling and handling prior to instrumental analysis are part of the overall data generation, it is appropriate to define in this first chapter of the book some terms that are commonly used in conjunction with measurements. The focus here is on a brief overview of quality control measures with regard to sampling which can be performed by analytical laboratories. This subject has been covered comprehenavely by Keith et al. (1983) and Keith (1991). 

The proof of activity of a biological pesticide is typically evaluated by a standardized bioassay except in the case of microbial metabolites where the major active ingredient(s) may be measured by analytical methods. Biological activity measurements, besides serving as a parameter for quality control, are an essential tool in the product development and optimization process. It is important to define the assay procedure in order to compare production batches and experimental formulations. These assays are typically used for product release or may be designed to assess specific aspects of product activity such as mobility in soils, colonization on leaf surface, etc. 

The choice of stabilizers used depends on the final formulation, i.e., aqueous suspension, non-aqueous suspension, wettable powder, dry flowable, etc. [4]. It may also be important to ensure stability of the formulation in tank mixes critical factors include water quality (pH, hardness, temperature, etc.), and the specific attributes of the mixes used. Use of surfactants, UV-protectants, humectants, and other diluents might be necessary to maximize the optimal application conditions and to ensiue stability of the active components on the foliage for extended biological efficacy. 

Successful commercialization of a biological product necessitates the integration of various production steps discussed earlier with quality control measiues to ensure product consistency, stability, and efficacy. This is the most important factor that can differentiate a successful product from an ineffective one. One of the important attributes that dictate the quality of the final product is the quality of the raw materials used in fermentation and formulation itself 

Packaging used for finished products can significantly affect the quality of the final product at the distribution and warehouse location. The final package should meet all lATA (International Air Transport Association), DOT (Department of Transportation), UFC (Uniform Freight Glassification), uniform packaging codes and transportation requirements for both dry and liquid biopesticides. 

The twentieth century has often been cahed the Century of Productivity the twenty-first century may well be the Century of Quahty (1). A discussion of how the chemical industry is organized to develop and manufacture quahty products is available (2). 

Early Activities. Historically, quahty was entmsted to the artisan, who was solely responsible for the products made. Thus financial success often rested on product quahty. The industrial revolution replaced this system with one in which product quahty was the result of the combined efforts of a group of factory workers. Quahty was ensured through the combination of worker skills and production supervisor monitoring. 

The adoption of the Taylor system in the late nineteenth century changed the lines of responsibihty for product quahty (4). This management philosophy was based on using incentives, such as pay based on output, to motivate worker productivity. As the workforce became better educated and labor unions gained strength, it became difficult to motivate workers doing simple, repetitive tasks (5). 

The Taylor system, successful in the United States until the end of World War II, resulted in a dramatic increase in productivity. The transfer of responsibihty for product quahty from production to the QC laboratory allowed production to emphasize productivity, relying on quahty control to keep nonconforming products from reaching the customer. In the years following World War II, quahty became secondary to productivity (6). 

Quality in Japan. Japanese economic prowess has been attributed variously to such quahty improvement activities as quahty circles, statistical process control (SPG), just-in-time dehvery (JIT), and zero defects (ZD). However, the real key to success hes in the apphcation of numerous quahty improvement tools as part of a management philosophy called Kaizen, which means continuous improvement (10). 

1 Cost Estimation from Mass-manufacture Scenarios for Chip-based Microfabrication 

Wegeng et al. refer to the low-cost, mass production of microstructures from metals, ceramics, and plastics as a crucial element for widespread application [Ij. Micro technologies, they say, are generally conducive for mass production however, this has so far only been proven for the field of microelectronics. 

Off-the-shelf catalogue sales of micro reactors have just started [15]. With an increasing number of commercial products, quality control will become more important. Brandner et al. describe quality control for micro heat exchangers/reactors at the Forschungszentrum Karlsruhe [23]. All manufacturing steps are accompanied by quality control and documentation. Leak rates (down to 10 mbar 1 s for He) and overpressure resistance (up to 1000 bar at ambient temperature) are measured. Under standardized conditions, the mean hydraulic diameter is determined. Dynamic tests supplement this quality control. 

Snrrogates chosen to monitor any of these areas should ideally bracket the range of the property. However, it should be pointed out that very few individual methods specify surrogates that provide information on all these areas, let alone bracket the property. The analyst must determine the suitability of the surrogate to reflect the properties and behavior of the analytes as well as the ability of the snrrogate to be nsed for the collection of reliable and defensible data. 

Quality controls are single procednres that are performed in conjnnction with an analysis to help assess the snccess of the analysis in a qnantitative manner. Examples of qnality controls are blanks, calibration, calibration verification. 

Unlike quality assurance plans, which address primarily regulatory requirements involving comprehensive documentation, quality control programs are science based, the components of which may be defined statistically. The two most important components of quality control are (1) determination of the precision of analysis and (2) determination of the accuracy of measurement. 

Whereas precision (Section 6.5) measures the reproducibility of data from replicate analyses, the accuracy (Section 6.4) of a test estimates how accurate the data are, that is, how close the data would represent probable true values or how accurate the analytical procedure is to giving results that may be close to true values. Precision and accuracy are both measured on one or more samples selected at random for analysis from a given batch of samples. The precision of analysis is usually determined by running duplicate or replicate tests on one of the samples in a given batch of samples. It is expressed statistically as standard deviation, relative standard deviation (RSD), coefficient of variance (CV), standard error of the mean (M), and relative percent difference (RPD). 

The standard deviation in measurements, however, can vary with the analyte concentrations. On the other hand, RSD, which is expressed as the ratio of standard deviation to the arithmetic mean of replicate analyses and is given as a percentage, does not have this problem and is a more rational way of expressing precision  

Arabic word meaning lawful or permitted , and eating halal is obligatory for every Muslim. The opposite of halal is haram, which means prohibited . Whether a company fulfils the requirements for a kosher or halal production or not can be examined and certificated by specially qualified people or organisations. For further information, see the recently published books concerning kosher [3] and halal [4] production. 

A prerequisite for any quality control is the definition of how the characteristics of a specific raw material, an intermediate product or a final product of a manufacturing process should be described. This means that all characteristics for every single product have to be defined in adequate standards and specifications so that the results obtained can be compared with these data. Numerous standards and specifications have been established in more or less official specification collections, for example pharmacopoeias, the aforementioned ISO or DIN standards, standards of the Essential Oil Association or the American Spice Trade Organization (ASTA). 

According to [6], the main objectives of the quality control in the flavour industry concern the following items  

The extensive quality control tests of raw materials, intermediate and final products represent a flood of data which have to be evaluated and documented according to the different aims of the quality control system. Considering the fact, that quality control often has to work under deadline pressure this work can only be done by using powerful electronic labour information and management systems (TIMS). 

Statistical averages need to be performed to obtain accurate results. This is known to apply to all kinds of measurements on rubber but is often neglected. Eor example, swelling investigations corroborate the inherent inhomogeneity of technical rubber and correlate well with measurements of T2eS- The same applies to mechanical testing [6]. 

Although theoretical models [1] exist, the correlation of r2efrwith crosslink density is done in practice by calibration [1, 7], because not only the formulation but also the processing conditions and the state of cure are of importance. Moreover, it 

In unilateral NMR, a magnet and the RF communication antenna are placed on the object, which can be much larger than the magnet. With permanent magnets, NMR sensors as small as a computer mouse can be built and positioned on intact objects at different places to measure T2, which goes hand in hand with molecular mobility. 

The possibility of using the NMR-MOUSE for nondestructive online monitoring of adhesive curing for car windshields has been investigated [11]. 

Whether it is possible to detect different crosslink densities in different heat-curing PU adhesives was checked. The crosslinking appears at 140 °C with a 30 min 

The films described should liberate amounts of Cl sufficient to form protective adsorption layers on the metal surface before the initiation of intensive corrosion processes. 

Single-layer inhibited films can neither present a insurmountable barrier to diffusive permeation of corrosion-active agents from the outside, nor they can avert infiltration and condensation of water vapor on the metal surface, but are able to hamper the removal of ion products from the zone of electrochemical reactions. The corrosion protection barrier factor is drastically improved in multilayered film materials. 

Like any other kind of commercial goods, inhibited polymer films should comply with certain quality parameters and requirements indicated in standards and technical specifications. 

Such characteristics as the external view of the films, their linear dimensions, deformation and strength parameters, and Cl concentration are 

The linear dimensions of the films refers to their width and thickness. The thickness of the films is an important parameter as it reflects stability of molding regimes and defines their strength. The measurement procedure for linear dimensions of films is specified in both national and international standards [139-142]. Relative changes in linear dimensions of heat-shrink films under elevated temperatures are characterized by a shrinkage parameter 

The SiC content of silicon carbide products is now usually determined by measuring the carbon contents. The total carbon content is determined by combustion of the sample in a stream of oxygen at 1050°C in the presence of lead borate. The CO2 produced is absorbed in Ba(C104)2 solution and determined by coulometry [236,237]. An alternative technique is to oxidize the SiC with oxygen in a high-frequency induction furnace containing a flux metal, and to detect the CO2 produced by IR absorption. 

Analyzers with IR detection are also suitable for the direct determination of free carbon provided that they allow precise temperature control during combustion of the free carbon. 

The SiC content is calculated from the difference between total and free carbon weight-% SiC = (weight-%Ctotai - weight-%Cfree) x 3.3383 

In order to characterize SiC powders and sintered ceramics the total oxygen and nitrogen content as well as the contents of metallic impurities are analyzed. Total oxygen and nitrogen contents are usually determined by an inert gas fusion method (Leco TC 436) using powdered samples, whereas metallic impurities (Na, K, Ca, Mg, V, Fe, Ti, Al, Cr and Ni) and boron content are determined in acidic solutions by inductive plasma emission (ICP) spectroscopy [240-242], 

Besides chemical analysis, physical properties such as particle size, particle size distribution, and bulk density are also important. 

QC samples are used to monitor assay performance during validation testing and after implementation of the new method. QC samples are included on each analytical run and used to determine if a run is acceptable or not. In some cases, 

Dilution Factor Concentration (ng/ml) x Dilution Factor (%Recovery)  

In this example, linearity of dilution identified matrix effects in dog urine samples. Minimum required dilution for dog urine was identified as 1 80, a dilution where recovery of the analyte shows reprodudbiUty of results. 

QC samples are supplied with commercial kits. In cases where QC samples are not provided, alternative commercial sources or internal preparation of QC samples is needed. One option is the preparation of species-specific sample pools containing the analyte of interest (spiked or endogenous), which are then divided into aliquots and stored (e.g., -70°C) for subsequent use as QC samples. Prior knowledge that the analyte is stable under frozen conditions is required when using these prepared QC samples. Homogenates prepared from tissues that are known to be a source of the protein biomarker can also be useful for preparing QC samples. 

Results from a particular marker used more than once with the same sample should be consistent. For example the total number of T cells measured by CDS positivity should be equal to the sum of CD3 /CD4 (T helper) and CDS /CDS (T suppressor) cells. When the results do not corroborate the source of the discrepancy should be investigated. This may be trivial, such as improper gating or alignment of the statistical regions. If the results are significantly different the samples should be re-evaluated for those markers in case there was inadequate staining with the antibodies. 

When two different mAbs are used simultaneously in defining a cell subpopulation, controls should be included that define the four possible cell populations, i.e. cells that are negative for both fluorochromes, cells which are positive for either FITC or PE, and cells which are positive for both FITC and PE. 

since there may be more than one staining characteristic (e.g. dim and bright ) within one or more of these populations, statistical regions may need to be adjusted for accurate assessment of populations which exhibit dual fluorescence. 

The percentage of different WBC in peripheral blood is shown in Table 3. Since the lymphocyte component is approximately 20-40% of the nucleated cell count, FACS analysis of lymphocyte subsets is done with approximately 10000 cells yielding an appropriate number of lymphocytes to analyse. In contrast, since the number of CD34 cells is often less that 1% of WBC in blood. BM, and PBSC harvests, quantitation requires at least 20000 ceU to be analysed. 

After studying this chapter, the student will be able to  

Cause-and-effect (C E) diagram (fishbone diagram)—a method for summarizing available knowledge about the causes of process variation. 

Control charts (SPC charts)—statistical tools used to determine and control process variations. Flowchart—a picture of the activities that take place in a process. 

Forms for collecting data—can vary from notes jotted down on a napkin to complex, preprinted documentation tools. 

Histogram (frequency plot)—a graphical tool used to understand variability. The chart is constructed with a block of data separated into 5 to 12 bars or sections from low number to high number. The vertical axis is the frequency and the horizontal axis is the scale of characteristics. The finished chart resembles a bell if the data is in control. 

All injectable solutions are tested for sterility and absence of pyrogens. 

Different approaches are used in setting up QC. QC as in testing are discussed but often the least understood. Usually it involves the inspection of materials and products as they complete different phases of processing. Products that are within specifications proceed, while tliose that are out of specification are either repaired, recycled, or scrapped. Possibly tlie workers who made the out-of-spec products are notified so they can correct their mistake. 

The approach just outlined is after-the-fact approach to QC all defects caught in this manner are already present in the product being processed. This type of QC will usually catch defects and is necessary, but it does little to correct tlie basic problem(s) in production. One of tlie problems with add-on QC of this type is that it constitutes one of the least cost-effective ways of obtaining high quality products. Quality must be built into a product from the beginning of the design that follows tlie FALLO approach (Fig. 1.15) it cannot be inspected into the process. The target is to control quality before a product becomes defective. 

Other available sensors include the measurement of formation, roughness, and porosity. 

Further sensors are still in the process of development and cannot be treated as standard sensors. These include sensors for fiber orientation, strength properties, etc. 

However, there still remain many important paper properties which are not yet measurable on-line, and where on-Kne measurements will probably not be available in the near future. Most important to note in this category is printabihty. A printability sensor, e. g., would be able to predict missing dots in a real printing test. 

Some of those properties wUl be measurable using so called soft sensors . For example a soft sensor for porosity would measure porosity based on a cabbration of about 100 process data against corresponding laboratory measurements of porosity. 

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Chromatographic techniques, particularly gas phase chromatography, are used throughout all areas of the petroleum industry research centers, quality control laboratories and refining units. The applications covered are very diverse and include gas composition, search and analysis of contaminants, monitoring production units, feed and product analysis. We will show but a few examples in this section to give the reader an idea of the potential, and limits, of chromatographic techniques. 

These specifications and characteristics are defined with references to standard test methods which the different parties to a contract should conduct for quality control. The tables that follow show specifically the standards that are applicable in France, but a more general table in Appendix 2 shows the main test methods commonly referenced in specifications. 

A specification or standard for product characteristics is valid only if it is matched with references to well defined and recognized test methods, such that quality control tests conducted by the parties involved —client and supplier, for example— are comparable even if they are performed at different locations. 

To realize a process integrated quality control the conception shown in fig. 2 was followed. The casting process which is influenced by process parameters like thermal economy, alloy composition or black wash will be pursued with particulary to the problematic nature adjusted sensoring systems. On basic factors orientated sensoring systems like microfocus radioscopy, and tomography will be employed and correlated with sensoring systems which can be applicated under industrial conditions. 

The authors thank the german research community (DFG) for the support of the presented investigations whieh were realized inside the Special Research Area 326, named, J rocess Integrated Quality Control with Quality Information System for Metallic Parts in Mechanical Engineering, and special thanks to the scientific bilateral project between Brazil and Germany supported by the CNPq, KFA and DLR to realize the presented investigations in advanced radioscopy and tomography. 

Homogeneity of data. Homogeneous data will be uniform in structure and composition, usually possible to describe with a fixed number of parameters. Homogeneous data is encountered in simple NDT inspection, e.g. quality control in production. Inhomogeneous data will contain various combinations of indications from construction elements, defects and noise sources. An example of inhomogenous data are ultrasonic B-scan images as described in [Hopgood, 1993] or as encountered in the ultrasonic rail-inspection system described later in this paper. 

Such a model can be developed to a new design to get a feedback (FB) and build up a quality control system for materials. This scheme also includes smart block (SB) for optimal control and generation of a feedback function (Figure 1). 

During take-off and landing, the wheels of modem aircraft are subject to great stress. New high-performance brake systems and aggressive environmental influences push the wheels closer and closer to their limit. These conditions as well as increased requirements for safety and quality control now necessitate that wheels are tested much more comprehensively than in the past. 

Of all NTD methods for quality control of materials, products, welded and soldered joints the most informative and perspective are radioscopic ones that enable to obtain a visual image of an inner structure of a tested objects in real time under any projection. 

During many years in Scientific Research Institutes of Nuclear Physics and Introscopy at Tomsk Polytechnical University (TPU) researches into induction electron accelerators and their uses for non-destructive radiation quality control of materials and articles have been conducted. Control sensitivity and efficiency detection experimental researches have been conducted with the high-current stereo-betatron modifications [1], and KBC-25 M and BC-50 high-current betatrons [2,3] in range of 11 MeV and 25-50 MeV radiation energy. 

The detection sensitivity of radiography is related among others to the properties and quality of industrial x-ray film systems. Changes of the products, variations due to different emulsions and combinations of products of different manufacturers can influence the decisive properties of film systems as classified in EN 584-1.To ensure the quality of industrial x-ray film systems a system for quality assurance open to all interested parties is proposed which is based on periodical round robin tests and quality controls of the manufacturer or an independent third party institution. 

It was assumed that the inspection will be carried out always with the same quality controlled detection medium. 

BE-3743 On-line quality control, production process assessment and tracking system for mechanical Darts ProT. Cerloa Fernandea UnN. Pol. Madrid... 

The results showed that some yards used ultrasonics to examine thousands of checkpoints for quality control purposes whilst others were content to examine the almost the minimum number that would be accepted. It is cleeu from the results that the minimum extent of NDE recommended by Classification Societies falls some way short of that applied for quality control purposes by some shipbuilders. 

As stated above the Surveyor s role will include an assessment of the yard s quality control department including the suppliers of any contracted NDE services. The Surveyor will look for the employment of qualified personnel, the availability of adequate inspection procedures and the presentation of definitive NDE reports. 

Agreement on the NDE plan will be dependent on the extent and relevance of theschedule. Under the amendments proposed to the Rules Surveyors will check that structurally significant welds are included in the shipyard s quality control programme. When agreement has been reached the Surveyor will endorse the plan. 

During the construction of a ship the Surveyor monitors NDE results for completeness of testing and overall quality of welding. This role includes the evaluation of checkpoints taken specifically for classification purposes but also includes the monitoring of additional checkpoints taken for quality control purposes by the builder. In the case of tankers built to LR Class since 1994 and for bulk carriers built to Class since January 1996 the Surveyor will witness the actions listed as part of the ShipRight Construction Monitoring procedure that is now mandatory. 

Laser-based profilometry is now being applied to a wide variety of both NDT and Quality Control gauging applications. In the world of NDT, the primary interest is in the details associated with surface topography or deformation of a particular component. Laser-based profilometry systems are commonly used to inspect surfaces for defects such as pitting, corrosion, deformation and cracking. Quality control gauges are used for absolute measurement of dimensions, such as the diameter and thickness of a given part. 

It is often important in practice to know when a process has changed sufficiently so that steps may be taken to remedy the situation. Such problems arise in quality control where one must, often quickly, decide whether observed changes are due to simple chance fluctuations or to actual changes in the amount of a constituent in successive production lots, mistakes of employees, etc. Control charts provide a useful and simple method for dealing with such problems. 

Guidelines for Data Acquisition and Data Quality Control Evaluation in Environmental Chemistry, Ana/. Chem. 1980, 52, 2242-2249. 

The focus of this chapter is on the two principal components of a quality assurance program quality control and quality assessment. In addition, considerable attention is given to the use of control charts for routinely monitoring the quality of analytical data. 

A final component of a quality control program is the certification of an analyst s competence to perform the analysis for which he or she is responsible. Before an analyst is allowed to perform a new analytical method, he or she may be required to successfully analyze an independent check sample with acceptable accuracy and precision. The check sample should be similar in composition to samples that the analyst will routinely encounter, with a concentration that is 5 to 50 times that of the method s detection limit. 

The written directives of a quality control program are a necessary, but not a sufficient, condition for obtaining and maintaining an analysis in a state of statistical control. Although quality control directives explain how an analysis should be properly conducted, they do not indicate whether the system is under statistical control. This is the role of quality assessment, which is the second component of a quality assurance program. 

Example of a prescriptive approach to quality assurance. Adapted from Environmental Monitoring and Support Laboratory, U.S. Environmental Protection Agency, "Handbook for Analytical Quality Control in Water and Wastewater Laboratories," March 1979. 

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