Proficiency testing catalogue - LGC Standards

QWAS - Water microbiology schemeThe QWAS scheme is solely intended formicrobiological analysis of waters, effluents andsludges and helps microbiologists demonstratereliable results when conducting analysis on awide range of water test materials. QWAS canhelp laboratories to meet the requirements ofthe laboratory standard ISO/IEC 17025, whichstates that analytical results must be monitoredusing external quality assessment, and theEU Directive 98/83/EC dealing with the qualityof water for human consumption.The test materials are provided in a stable,lyophilised format and QWAS participants canchoose any combination of simulated potable,process and surface/wastewater materials,or an environmental water test material forLegionella testing. There is also an effluentsludge test material to allow participants tomonitor treated sewage sludge which is usedas an agricultural fertilizer. A sea water testmaterial for bathing purpose as monitored by theEU for awarding ‘blue flag’ status for beaches isalso available.Microorganisms may be reference strainssourced from national culture collections, ormay be fully characterised wild strains. Whenreconstituted, test material quantities vary,depending upon the microbiologicalspecifications for the organism under test.Atypical strains may occasionally be includedin test materials. Atypical strains can occur in‘real’ samples and could be undetected ormis-identified. It therefore represents a realisticchallenge to occasionally include atypical strainswithin a PT scheme.For laboratories that perform the analysis ofwater, participation in a relevant proficiencytesting scheme can provide confidence thatresults of these analyses are meaningful andaccurate which, in turn, helps to ensure thesafety of water.The full range and availability of test materialsin QWAS is determined on an annual basis andfurther details can be found in the QWASapplication form and scheme description.Test materialWaters (Various e.g. bathing,environmental, mineral, potable,process, recreational, sea, surface,waste) and Simulated EffluentSludge.AnalytesEnumeration:Clostridium perfringens, Coliforms,Enterococci (faecal streptococci),Escherichia coli, Faecal coliforms,Legionella species,Pseudomonas aeruginosa,Pseudomonas species,Staphylococcus aureus,Total coliforms, Yeast and Mould.Total aerobic mesophilic count,Total aerobic mesophilic countat 22°C,Total aerobic mesophilic countat 37°C.Presence/absence:Sulphite – reducing clostridia,Salmonella species.Note: Test materials and analytes may be added or removed, pleasesee current application form.Water andenvironmentPT schemesEmail: customerservices@lgcpt.comWebsite: www.lgcpt.com29