Dichlorodiphenyltrichloroethane determination in air by thermal desorption gas chromatography-mass spectrometry

BACKGROUND: Current quantitative methods for airborne dichlorodiphenyltrichloroethane (DDT) require collection and extraction times of = 12 h. The aim of this study was to develop a method for quantifying airborne DDT with a short (<4 h) collection and analysis time. RESULTS: Precision [relative standard deviation (RSD)] for each calibration point (0.89.0), linearity (R2 = 0.99) and apparent recovery (R' = 96.5%) were determined from thermal desorption (TD) gas chromatographymass spectrometry (GC-MS) analyses of Tenax-TA-packed sampling tubes spiked with 1250 ng of DDT. Recovery of 13C-labeled 4,4'-DDT from tubes spiked before and after air sampling was 97.3 and 90.3% respectively. DDT was detected and quantified in 13 L samples of air collected during 10180 min sampling events. A significant difference was observed in DDT air concentration between 28 and 33 degrees C during microchamber studies. CONCLUSIONS: The results demonstrate that the TD GC-MS method developed in this study is precise, reproducible and linear over the span of 1250 ng of DDT spiked onto TD tubes. By avoiding dilution of the sample, the method described allows the measurement of DDT vapor concentrations during short sampling periods (10180 min) relevant to mosquito behavior studies. Published 2012 by John Wiley & Sons, Ltd.