Proficiency testing organic analysis

Some important assays commonly used in biochemical genetics laboratories do not provide quantitative data (e.g. MPS-EP, qualitative urinary organic acid analysis, AA-TLC). In addition, all successful investigations depend heavily upon selection of the correct analytes to measure and the appropriate interpretation of the quantitative or qualitative results in their clinical context. These challenges suggest a requirement for external quality assessment or proficiency testing schemes that can inform participants about their performance in these areas when compared with other centres. 

Matrices most used were soil, water, and organic liquids. Other matrices used were, for example, a polymer strip in the first proficiency test, a metal strip covered with a thin layer of paint in the third proficiency test, and a wipe sample in the fourth proficiency test. In the ninth and tenth proficiency tests, an emulsion sample and decontamination solutions were introduced. Not all sample matrices employed in the past are considered realistic. During the Preparatory Commission of the OPCW, the Task Force on Analytical Issues (see Fourth Report of the Expert Group on Inspection Procedures, PC-VIII/B/WP.12, dated September 20, 1994) discussed that sample matrices such as wipe, rubber, paint, and concrete will be extracted on site and sent as extracts off site for analysis, after splitting. 

The Technical Secretariat of the Organization for the Prohibition of Chemical Weapons (OPCW) provides a proficiency-testing scheme for the analysis of samples in the context of the CWC. The design of the scheme should simulate analysis of authentic samples that are taken during inspections. The purpose of the scheme is to select, certify, and train highly competent laboratories for the analysis of CWC-related chemicals in various matrices. The Technical Secretariat designates laboratories, which perform successfully in the scheme, to support it in such analysis should they become necessary during the course of its verification activities. 

In the tenth official proficiency test, the presence of bis(2-hydroxyethyl) sulfone) (BHES, CAS 2580-77-0) in the decontamination solution sample D2 was missed by one laboratory. The laboratory performed liquid-liquid extraction of the aliquots with dichloromethane and benzene, concentrated the organic extracts, and silylated them. One aliquot of the organic extract was evaporated to dryness, dissolved, methylated, evaporated to dryness, and dissolved again. Evaporation of the water phase to dryness and silylation of the residue was not reported, and the failure to do this might be the reason why the laboratory did not identify BHES using GC-based methods for analysis. 

For this aim, three proficiency testing (PT) campaigns were organized within the SWIFT-WFD project, mainly dedicated to the determination of the list of priority pollutants annexed to the WFD. The SWIFT-WFD PT campaigns, one per year for three years, were organized on 17 reference materials (RMs) including 5 matrix RMs at natural concentration levels, 3 at low fortified concentration levels, 4 at fortified concentration levels, and 5 multi-analyte blind standard solutions, targeting the analysis of... 

The Central Chemical Laboratory (CLCh) is the primary analytical facility of the Polish Geological Institute (PIG) and carries out practically all the chemical analysis at PIG. CLCh took part in the INCO-COPERNICUS Project Development of Analytical Procedures to Guarantee Quality Assurance in International Environmental Monitoring . CLCh participated in numerous international inter-laboratory comparisons as well as organized various inter-laboratory comparatives and proficiency testing studies for laboratories of Provincial Environment Protection Inspectorates. In March 2000, CLCh was granted the Certificate of Testing Laboratory Accreditation, with respect to physical and chemical analyses of water. 

Companyo R, Rubio R, Sahuquillo A, Boque R, Maroto A, Riu J, Uncertainty estimation in organic elemental analysis using information from proficiency tests. Anal. Bioanal. Chem. 2008 392(7-8) 1497-1505. 

In each case a referee laboratory is responsible for providing the sample and organizing its distribution and the collation and analysis of the results. For the majority of studies the purpose of the study is to test the laboratory (proficiency testing), the test material (material certification), or the method (method validation study). The purpose determines some of the study parameters. For example, a method validation study requires all the laboratories to use the same method, but for other studies the method may not be prescribed. For materials certification the laboratories are chosen for their demonstrated proficiency in analysis of the material. It would not be appropriate if there was any dubiety concerning the assigned quantity value because of a suspect result. 

In 1997 the Laboratory Enviroimiental Analysis Proficiency (LEAP) Emergency Scheme was initiated. The primary function of this scheme is to establish the reliability of water testing laboratories to determine the contents of a simulated potable water contamination sample. In the event of a potable water contamination incident, water testing laboratories may be called upon to rapidly identify contaminants that are present in the water with little information about the likely source of contamination. Samples are analysed for inorganic and organic chemical contamination. 

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