Determination of organochlorine pesticides in leather by solid-phase microextraction and gas chromatography-mass spectrometry
Silveira, Cristine Durante de Souza; Carasek, Eduardo
Palavras-chave: organochlorine pesticides, HS-SPME, GC-MS, leather.
Resumo: An analytical procedure based on the solid-phase microextraction technique (SPME) combined with gas chromatography-selected ion monitoring-mass spectrometry (GC-SIM-MS) for the determination of organochlorine pesticides (OCPs) extracted directly from leather samples is proposed. The extraction conditions for the headspace SPME (HS-SPME) procedure were optimized using experimental designs. The fibers and the ionic strength were optimized by the univariate procedure, while a Doehlert matrix was used to optimize the extraction time and temperature. The best extraction conditions were obtained using a PDMS/DVB fiber with extraction time and temperature of 35 min and 80 oC, respectively. No salt addition was necessary. Detection limits ranging from 3.3 to 11 ng g -1 and relative standard deviations (RSD, n = 5) lower than 14.2% were obtained. The recovery was studied at three concentration levels by adding different amounts of organochlorine pesticides to the leather samples (600, 900 and 1500 ng g -1 ) and excellent recoveries ranging from 93.7 to 107.3% were obtained.