Laboratories working towards accreditation by the International Standards Organization (ISO) 15189 standard are required to demonstrate the validity of their analytical methods. The different guidelines set by various accreditation organizations make it difficult to provide objective evidence that an in-house method is fit for the intended purpose. Besides, the required performance characteristics tests and acceptance criteria are not always detailed. The laboratory must choose the most suitable validation protocol and set the acceptance criteria. Therefore, we propose a validation protocol to evaluate the performance of an in-house method. As an example, we validated the process for the detection and quantification of lead in whole blood by electrothermal absorption spectrometry. The fundamental parameters tested were, selectivity, calibration model, precision, accuracy (and uncertainty of measurement), contamination, stability of the sample, reference interval, and analytical interference. We have developed a protocol that has been applied successfully to quantify lead in whole blood by electrothermal atomic absorption spectrometry (ETAAS). In particular, our method is selective, linear, accurate, and precise, making it suitable for use in routine diagnostics.
Accreditation ; Humans ; Laboratories/standards ; Lead/*blood/standards ; Reference Standards ; *Spectrophotometry, Atomic/standards ; *Validation Studies as Topic

OBJECTIVETo develop a method for determining the content of mercury contained in Yuhong ointment.

METHODThe wet catalytic digestion method was adopted for the pretreatment, and the mercury content in Yuhong ointment was determined by hydride generation-atomic absorption spectrometry (HG-AAS).

RESULTThe mercury showed a good linear relation in the range from 2 to 20 microg x L(-1), with the average recovery of 104.27% and RSD of 3.37%. The RSD for real sample repeated measurement was determined to be 8.4%. The mercury content in Yuhong ointment was detected in range from 0.7 to 1.5 mg x g(-1).

CONCLUSIONThe proposed method is accurate, highly reproducible and it can be used to control mercury content of Yuhong ointment.

Catalysis ; Drugs, Chinese Herbal ; chemistry ; Mercury ; analysis ; isolation & purification ; Ointments ; Reference Standards ; Reproducibility of Results ; Spectrophotometry, Atomic ; methods