Independent analytical procedure

The method for 1,2-DCP was evaluated in the concentration range of 0.124 to 128 mg/m3 in 3-L air samples. The average bias from the independent analytical procedure (total hydrocarbon analyzer) was less than 1% over the range of the method. The pooled relative standard deviation was 6.4% over this range. 

TJecent interest in the trace element content of coal has increased the need for rapid and accurate analytical methods for their determination. Because x-ray fluorescence analysis has demonstrated its usefulness in determining major, minor, and trace elements in numerous other types of materials, it was felt that this method could be extended to trace element determinations in whole coal. In the past, such analyses were seriously hampered by the lack of standard samples. However, research being conducted in our laboratories under the sponsorship of the U. S. Environmental Protection Agency produced a large number of coal samples for which trace elements had been determined by two or more independent analytical procedures, for example, optical emission, neutron activation, atomic absorption, and wet chemical methods. These coals were used as standards to develop an x-ray fluorescence method that would determine many trace and minor elements in pressed whole coal samples. 

Accuracy by Comparison. For drug substance, the only possibility of a quantitative assessment of accuracy is the comparison to the results of another analytical procedure or to a reference (if established with other procedures and/or additional characterization). This can be performed statistically with a r-test (see statistical textbooks or corresponding software). However, the shortcomings of these statistical tests (or better the justification of their use) are especially important here. It must be taken into consideration that two independent analytical procedures most probably differ in their specificity. This may lead to a systematic influence on the results (Table 2). If the effect can be quantified, the means should be corrected before performing the statistical comparison. If a... 

To derive actual levels and establish quality measurement for trace elements in foodstuffs, materials such as milk powder (A-11) and representative regional dietary blends (eg, USDIET-1) have been provided (8.9 ). Consistency of interlaboratory results among "independent" analytical procedures makes possible the certification of such materials or the establishment of dietary intakes. The nature of the initial measurement problem is illustrated by the results of the milk powder (A-11) intercomparlson, where the means, relative ranges (max/min, dimensionless) and medians of 17 atomic absorption spectroscopy [AAS] and 7 radiochemical neutron activation analysis [RNAA] laboratory results for manganese were as follows. 

The limit of detection by square-wave voltammetry after a 20-s deposition time was found to be 0.1 mM and 1.0 mM with and without microwave activation, respectively. The Pb content in a water sediment sample detected by anodic stripping voltammetry at boron doped diamond electrodes is shown to be in good agreement with two other independent analytical procedures based on ICP mass spectroscopy and on sono-cathodic stripping voltammetry. 

Another major advantage of witness panels is that they make it possible to employ sophisticated analytical procedures to investigate the cause of serious bonding problems. Instrumentation such as HR-SEM, XPS, AES, FTIR, etc., which are discussed in detail in Chapter 6, are not customarily available in a production environment but there are many independent analytical laboratories that offer such services and whose personnel can be extremely helpful in diag-... 

The analytical procedure is checked by analyses of method blanlcs to assure that secondary contamination by the analytes to be determined is avoided or minimized. Because the water content of the CRM matrix to be analyzed may vary from one laboratory to another (dependent on the local humidity and temperature), the water content has to be determined. Accordingly, at least three independent samples are kept at I05°C for 2 h, then allowed to cool to ambient temperature in a desiccator and the water loss is determined. The certified values are generally reported on a dry mass basis. 

Brandt [200] has extracted tri(nonylphenyl) phosphite (TNPP) from a styrene-butadiene polymer using iso-octane. Brown [211] has reported US extraction of acrylic acid monomer from polyacrylates. Ultrasonication was also shown to be a fast and efficient extraction method for organophosphate ester flame retardants and plasticisers [212]. Greenpeace [213] has recently reported the concentration of phthalate esters in 72 toys (mostly made in China) using shaking and sonication extraction methods. Extraction and analytical procedures were carefully quality controlled. QC procedures and acceptance criteria were based on USEPA method 606 for the analysis of phthalates in water samples [214]. Extraction efficiency was tested by spiking blank matrix and by standard addition to phthalate-containing samples. For removal of fatty acids from the surface of EVA pellets a lmin ultrasonic bath treatment in isopropanol is sufficient [215]. It has been noticed that the experimental ultrasonic extraction conditions are often ill defined and do not allow independent verification. 

A clear differentiation between selectivity and specificity was firstly given by Kaiser [1972] together with a quantification of the both characteristics. According to him an analytical procedure is known as selective" if it can detect and determine simultaneously several components independently from each other. On the other hand, a procedure is known as specific if only one species can be detected and determined independently from all the other components which are present in the sample but does not contribute to the signal in this case. 

The mineral petalite was mined as an ore in Sweden. In 1817 Johan August Arfwedson (1792—1841) analyTed this new mineral. After identifying several compounds in the ore, he realized there was a small percentage of the ore that could not be identified. After applying more analytical procedures, he determined it was a new alkali. It turned out that petalite contains hthium aluminum silicate, LiAllSi O lj. In 1818 the first lithium metal was prepared independently by two scientists, Sir Humphry Davy (1778—1892) and W.T. Brande (1788—1866). Lithium was discovered at a time in the early nineteenth century when numerous new elements were discovered and identified by other scientists. Many of these newly named elements were predicted by the use of the periodic table of the chemical elements. 

The ICH recommends that repeatability be assessed using a minimum of nine determinations covering the specified range for the procedure (e.g., three concentrations/three replicates as in the accuracy experiment) or using a minimum of six determinations at 100% of the test concentration. Reporting of the standard deviation, relative standard deviation (coefficient of variation), and confidence interval is required. The assay values are independent analyses of samples that have been carried through the complete analytical procedure from sample preparation to final test result. Table 1 provides an example set of repeatability data. 

In terms of methodology, the speciation analysis of Hg has reached its maturity. Because of a convenient conversion of Hg species into volatile compounds, GC has been the dominant separation technique prior to Hg speciPc ICP-MS detection [10, 11, 13, 19]. HPLC methods cannot compete in terms of Pgures of merit with GC. HPLC-ICP-MS is, however, a valuable independent analytical technique that allows the formation of artifacts during derivatization in GC to be controlled. Owing to the availability of a number of CRMs, analytical procedures for the analysis of seafood samples were extensively validated and can be applied in routine analysis. 

In the absence of suitable reference materials, the procedure should be tested using different sample weights and also measuring recoveries of element added at the beginning of the procedure. It must be remembered, however, that these criteria although necessary, are not sufficient, for the complete demonstration of the validity of the analytical procedure. The application of an independent (different in all respects of sample treatment and analyte quantitation) analytical method to a homogeneous practice sample would provide very useful confirmation of method reliability. 

Because of its diatomic nature and permanent quadrupole moment, the physisorp-tion of nitrogen at 77 K presents special problems. The application of DFT is facilitated if the molecules are assumed to be spherical, which was the approach originally adopted by Seaton et al. (1989) and also by Lastoskie et al. (1993). The analytical procedures already outlined in Chapter 7 (Section 7.6) do not depend on the meniscus curvature and are in principle applicable to both capillary condensation and micropore filling. The non-local version of the mean field theory (NLDFT), which was used by Lastoskie, gave excellent agreement with computer simulation when applied to the carbon slit pore model. However, as pointed out earlier, these computational procedures are not entirely independent since they involve the same model parameters. 

Spectroscopy as a two-dimensional analytical procedure provides ideally a number of independent channels of information, each at a definite wavenumber u with a width of Ai>. Let and define the upper and the lower limit of the usable intensity range, respectively, and a the standard deviation of the measured intensity values. On the assumption that these values obey a Gaussian distribution the potential amount of information Ipot which a spectrometer may transfer during a time r is given by (Eckschlager, 1969 Doerffel and Hildebrandt, 1969 Kaiser, 1970 Doerffel and Eckschlager, 1981) ... 

Directions of Analysis Analytical procedures depends on the type of problem set. Unknown circumstances of an event or an unknown toxic factor require the application of systematic toxicological analysis (STA), so that the analytical procedure encompasses as many toxic substances as possible. In cases where the administered toxic compound is known, first of all a course of analysis targeted at this compound is conducted, and a positive result must be confirmed by another independent method. When working on a case in which only the symptoms of the action of an unknown toxic factor are given, the ability to use complementary techniques as well as knowledge of the fields of medicine, pharmacology and pharmacokinetics are of particular importance [53]. 

Fernery s corpuscular definition, albeit speculative, provided an ontology of acids and alkalis independent of their manner of preparation. As such, it could cross the boundaries of different analytic methods and serve as a universal definition. While the proliferation of analytic procedures employing acids and alkalis increasingly removed them from the procedural roots of distillation, chemists could deploy the corpuscular ontology to transplant them to a new analytic environment. The protean points of acids and pores of alkalis made such transposition possible. The corpuscular language also helped Fernery to unpack esoteric chemical practice for the consumption of fashionable Parisians who were drawn to his popular lectures. 

In cases where a general QL is required, as in pharmaceutical analysis, it is essential to define a realistic QL (or DL) for the analytical procedure, independently from the equipment used, because this limit has important consequences (e.g., for the consistent reporting of impurities or for method transfer). They may be derived by taking QL (or DL) from various instruments into account ( intermediate QL, during the development process) or can be defined taking the requirements of the control test (specification limits imposed by toxicology or by a qualified impurity profile) into consideration. For example, a QL which... 

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