Quality control programmes

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. 

Booth E. Crofton P and Roberts LB (1974) The influence of standards on interlaboratory quality control programmes. Clin Chim Acta 55 367-375. 

The inherent reproducibility or imprecision of the method will have been determined as part of the validation procedure. This information can then be applied to the internal quality control programme which is designed to identify the intrusion of a bias (inaccuracy) and/or an alteration in the reproducibility of the assay. Programs for Internal quality control are most extensively developed for clinical laboratories because of the availability of suitable RMs in large batches and at an affordable cost although some level of IQC is appropriate to aU work carried out at a continuing basis see Section 6.2. 

The guidelines also stress that the perfunctory execution of any quality system will not guarantee the production of data of adequate quality. The correct procedures for feedback, remedial action and staff motivation must also be documented and acted upon. In other words, there must be a genuine commitment to quality within a laboratory for an internal quality control programme to succeed, i.e. the IQC must be part of a complete quality management system. 

Control samples should be analysed along with the test samples but the analyst should not know which are the control samples. Knowing the mean value for the control sample and the precision expected from the method, it is possible to forecast limits within which a single control result should normally fall. The basis of a quality control programme is the assumption that if a single control result falls within these defined limits, the method is under control and the test results produced at the same time are valid. If the control value falls outside the defined limits it is likely that the test results are in error and must be rejected. 

If a control sample in a quality control programme gives a value that is greater than the mean value for all the control samples by more than 2 SD it suggests that errors have been introduced into the assay BECAUSE... 

STL s quality-control programme includes the recovery of known additions of analyte, analysis of externally supplied standards, calibration, analysis of duplicates and control charting. Each analyte is monitored by analysing at least one AQC standard for every 20 samples. AQC results are plotted on control charts and action is taken if a point Hes outside +3 standard deviations (SD) or if two consecutive points He outside +2 SDs. 

Briggs (2002) reported some negative effects in layer diets when triticale was used at high dietary levels. These findings suggest that triticale should be part of a quality control programme on-farm before high levels are used in poultry diets. 

Producers who purchase complete feeds from a feed manufacturer will avoid the need to mix their own feeds but should adopt the relevant sections of the quality control programme outlined below. 

Every quality control programme should include periodic laboratory analysis of ingredients and mixed feed. Care should be taken to insure that samples are representative, by taking samples from various points in the batch, mixing them and then drawing a subsample of 500-1000 g for analysis. For bagged material a common approach is to collect a sample with a probe from 10-15% of the bags in the batch. It is advisable to use only one-half of the sample for laboratory analysis and to retain one-half as a back-up in case of subsequent problems, discrepancies or disputes. 

Quality assurance/quality control programmes are in place... 

To improve further the quality of pesticides used in public health, WHO should ensure the wide distribution of WHO specifications and should strengthen and expand pesticide quality control programmes. For reasons of human and environmental safety, efficacy and economy, pesticide products of good quality are essential. 

In implementing a good quality control programme, it is necessary to take into account the following ... 

Schaller, K.H., Angerer, J., Lehnert, G., Valentin, H. and Weltle, D. (1987). External quality control programmes in the toxicological analysis of biological material in the field of occupational medicine - experiences from three roundrobins in the Federal Republic of Germany. Fres. Z. Anal. Chem., 326. 643-646. 

Even although the chemical interferences on the zinc absorbance in an air-acetylene flame are few. some workers advocate the addition of Na and K to the aqueous standards to compensate for ionisation effects. In a detailed comparison of the performance of the commonly used AAS methods in an inter-laboratory quality control programme, Taylor and Bryant (1981) found that none of the methods was markedly superior to the others in terms of precision. They noted that the TCA method gave a higher mean result for plasma/serum zinc and that there was no evidence to support the addition of Na and K to the calibration solutions. 

Taylor JR, Quality Control Systems Procedures for Planning Quality Control Programmes, McGraw-Hill, 1988. 

An analytical procedure is characterized by its measurement range, imprecision, accuracy, linearity, quality control programme, reference interval and ease of performance. 

A quality control programme is the procedure employed to ensure that the analysis continuously meets the goal for imprecision and accuracy. Several external quality control programmes exist for measurement of cobalamin, e.g. United Kingdom National External Quality Assessment Service (www.ukneqas.org.uk). 

Mahaffey In the meeting a few weeks ago of the Association of Official Analytical Chemists, there was a full symposium on analytical methods for lead. The U.S. National Bureau of Standards does have certified reference materials for a number of food products that are appropriate for analysis of lead in food. One thing that is still missing is certified reference material for blood, and until we have that we have a lot of quality control programmes to follow. 

As part of the quality control programme and to support accreditation according to the EN lEC/ISO 17025 2005 [6], each batch of samples should contain a reference material to validate the results. As there are currently no suitable and traceable certified reference materials available, several in-house reference materials (RMs) were developed. One iron ore and one sinter dust were selected to be developed as RMs for the alpha spectrometry method and the same sinter dust along with a blast furnace dust were selected for the gamma spectrometry method. When analysing stack emission samples, one blank filter was spiked with a known amount of a certified Pb standard solution (R22-02, National Physical Laboratory, UK) and used as a reference for result validation. 

The quality of the works is ensured by the implementation of an appropriate Quality Control Programme. A well planned and executed Quality Control Programme benefits all parties. The Client, the Designer and the Engineer are ensured that the works are carried out in accordance with the Contract requirements whilst the Contractor can efficiently optimise the planning. In addition, monitoring may enable all parties to identify unforeseen inappropriate fill mass behaviour in an early stage of the construction. Immediate action can then be taken to hold technical and financial consequences to a minimum. 

Lead in whole blood (PbB) was measured for each of the 237 children, following the procedure of Fernandez (1975), with slight modifications. The accuracy of the analyses was ascertained by regular participation in the quality control programme organized by the United Kingdom (UKEQAS) and by the Italian Istituto Superiore di Sanita (Morisi et al, 1984). 

Umbilical cord blood and capillary blood samples, collected using standardized techniques (Australian Standards Association, 1983) at age 6 months, 15 months, 2 years, and annually thereafter, were assayed for blood lead (PbB). Blood lead assays were made using electrothermal atomic absorption spectrophotometry, after standard complexing and extraction of lead (Australian Standards Association, 1984). The laboratory undertaking the analyses participates in several national and international quality control programmes. Crude blood lead levels were standardized to a packed cell volume (PCV) of 35% before being included in subsequent data analysis (except in cord blood where standardization was to a PCV of 50%). A capillary-venous correlation coefficient of + 0.97 has been achieved in a sample of children of this age using these techniques (ACH, unpublished data). 

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