Method and records
Method and records: 7 articles from Peptides Info. Handling, storage and laboratory reference.
Control Charts in the Lab: Trending SST and QC Results
System suitability says whether one run passed. A control chart says whether the system is changing. Baseline construction, three-sigma limits, the Westgard rule set and where it fits chromatographic data, and a worked retention-time series.
Decision Rules and Guard Bands: Conformity With Uncertainty
The step after the uncertainty budget and before the report: choosing, agreeing and recording the rule that turns a result with an expanded uncertainty into a statement of conformity under ISO/IEC 17025 clause 7.8.6. Simple acceptance, guard bands of w = kU, binary and non-binary statements and the probability of a false accept, worked for a generic purity specification.
Method Validation Basics for a Small Laboratory
Specificity, linearity, accuracy, precision, range and robustness defined in plain terms — which of them an identity method needs, which a quantitative method needs, what full validation costs against verification, and a proportionate programme for a laboratory of three.
Out-of-Specification Results and What to Do About Them
The difference between out of specification and out of trend, why retesting is never the first move, how to interrogate the method before the material, the averaging trap, and what to do when a supplier certificate contradicts your own result.
The Laboratory Notebook and Contemporaneous Records
Why recording at the time is not the same as recording accurately later, the attributable-legible-original-accurate vocabulary, how to correct an entry without destroying it, bound versus electronic notebooks, and how long to keep them.
Uncertainty of Measurement in Practice
Why every result is a range rather than a number, how Type A and Type B contributions differ, a worked uncertainty budget for a weighing and a dilution, the coverage factor and reporting convention, and what a purity figure quoted without uncertainty is actually worth.
Writing a Standard Operating Procedure: A Template That Survives Being Followed
Scope, materials, procedure, acceptance, records — the five sections that carry an SOP, how to write steps somebody else can execute, how to version and review them, and a worked goods-in receiving skeleton to copy.