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Deviating Samples UKAS TPS 63. Tim Platt Technical Manager. Introduction. EA LC identified ISO/IEC 17025 REQUIREMENTS not being met Clause 5.8 and 5.10 Integrity of test samples maintained Results reported Accurately Clearly Unambiguously Objectively
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Deviating SamplesUKAS TPS 63 Tim Platt Technical Manager
Introduction • EA LC identified ISO/IEC 17025 REQUIREMENTS not being met Clause 5.8 and 5.10 • Integrity of test samples maintained • Results reported • Accurately • Clearly • Unambiguously • Objectively • Include comments on sample quality or adequacy that may have compromised the result
Terminology • Deviating • an abnormality or departure from what is expected • Deviating samples • Those not correctly cared for or sampled inappropriately.
Deviating Samples • Exceeded their holding time • Lack pertinent information • Date • Time • Location • Identity of sampler/contact • Not retained at appropriate temperature
Deviating Samples • Presented in inappropriate containers /packaging • Inappropriate headspace • Insufficient quantity • Denatured through heat/ light/ humidity • Suffered microbiologically
UKAS TPS 63 • 4.1 Policies and procedures in place • Sample integrity maintained • Ensure results reported accurately • Include comments on quality /adequacy where this may have impacted on results
UKAS TPS 63 • 4.2 Laboratory to define “deviating sample” • Holding time (stability) • Storage /transit conditions • Pertinent sample information (date/time/identity) • Use of appropriate containers • Use of preservatives • Sample type as defined in accreditation schedule
Sample Containers • Waters • Volatiles ,BTX, GRO – 60ml amber glass containers* • Other organics 1x 1 litre amber glass container* • Inorganics 1x1 litre plastic container • Sulphide, Phenols, Cyanide, Metals , individual plastic containers with preservative • * no headspace
Preservatives • Analyte- Preservative • Cyanide - Sodium hydroxide • Phenol - Sodium hydroxide • Metals - Nitric acid • Mercury - Potassium dichromate • BOD - Unpreserved, no headspace • Sulphide - Zinc acetate
Temperature control • Volatile and Organic samples or those affected by biological activity should be stored at 5°C • Samples should be stored in the dark • MCERTS for waters “the sample storage environment shall maintain a temperature of 5 ± 3°C” • Cool transportation – cool boxes, ice packs, fill box, pre-chill, min/max thermometer.
UKAS TPS 63 • 4.3 On identifying a deviating sample. • Consistent application/actions taken • Consult with customer and record • Initiate investigation into non- conforming work procedures if allowed to deviate in laboratory • Report results in appropriate manner.
UKAS TPS 63 • 4.4 Laboratory required to demonstrate • Sample assessed upon receipt • If found to be deviating – contact customer for instructions • If customer requests to proceed, report will include a disclaimer indicating deviating sample and results may be invalid • If deviation occurred after receipt – investigation required
Deviating SamplesUKAS TPS 63 Tim Platt Technical Manager