Determination of Aldrin Purity Using a Combination of the Mass Balance Approach and Quantitative NMR

This paper describes the studies performed to determine the purity of aldrin samples, an organochlorine pesticide, using the mass balance approach. The organic impurities were identified and quantified by gas chromatography-mass spectrometry (GC-MS), gas chromatography with flame ionization detection (GC-FID) and gas chromatography with electron capture detector (GC-mu ECD) using two columns: DB-35ms (intermediate polarity) and DB-XLB (low polarity). The water content was determined by Karl Fischer coulometric titration, and the inorganics were analyzed by inductively coupled plasma mass spectrometry (ICP-MS). The aldrin contents determined by mass balance and quantitative nuclear magnetic resonance (qNMR) were compared. The obtained results were validated through the participation of the National Institute of Metrology, Quality and Technology (Inmetro) in the key-comparison CCQM-K55.b organized by the Organic Analysis Working Group/International Bureau of Weights and Measures (OAWG/BIPM).