Development of a candidate certified reference material of cypermethrin in green tea.

This paper presents the preparation of a candidate certified reference material (CRM) of cypermethrin in green tea, GLHK-11-01a according to the requirements of ISO Guide 34 and 35. Certification of the material was performed using a newly developed isotope dilution mass spectrometry (IDMS) approach, with gas chromatography high resolution mass spectrometry (GC-HRMS) and gas chromatography-tandem mass spectrometry (GC-MS/MS). Statistical analysis (one-way ANOVA) showed excellent agreement of the analytical data sets generated from the two mass spectrometric detections.

The first international proficiency test on ketamine and norketamine in hair.

This paper discusses the organization of the first international proficiency test (PT) programme on ketamine (K) and norketamine (NK) in hair samples. The primary objective of the programme was to evaluate the analytical capability of participating laboratories on hair analysis for K and NK via comparison of results. Authentic samples, instead of spiked samples were used in the programme to mimic the analysis of incorporated illicit drugs in real-life situations.

Development of melamine certified reference material in milk using two different isotope dilution mass spectrometry techniques.

A new certified reference material (CRM) of melamine in milk GLHK-11-02 was developed aiming to address the great demand from the testing community after the melamine crises. The material was prepared by adding an appropriate quantity of melamine into the skimmed milk samples and the final product was in the form of fine lyophilized powder. Characterization of the material relied on two newly developed gravimetric isotope dilution mass spectrometry (IDMS) methods, one using liquid chromatography-tandem mass spectrometry (LC-MS/MS) and another gas chromatography-mass spectrometry (GC-MS).