Determination of 1,3-Dichloropropene Degradates in Water and Soil by Capillary Gas Chromatography with Mass Spectrometric Detection

Methods for the determination of cis- and trans- isomers of 3-chloroallyl alcohol (CAAL) and 3-chloroacrylic acid (CAAC) in water and soil were developed. Both CAAL and CAAC have been identified as major degradates of the soil fumigant, 1,3-dichloropropene (1,3-D). The methods required derivatization prior to quantitation by gas chromatography with mass spectrometric detection (GC/MS). CAAL residues were converted to the corresponding cis- and trans-3-chloroallyl isobutyl carbonates using isobutyl chloroformate. CAAC residues were converted to the corresponding cis- and trans-3-chloroacrylic acid t-butyldimethylsilyl esters using N-methyl-N-(t-butyldimethylsilyl)trifluoroacetamide (MTBSTFA). The GC/MS used electron impact ionization with selected ion monitoring (SIM) of two ions for each analyte. Recoveries for CAAL in surface water fortified at the 0.1 ng/mL level averaged 83% with a standard deviation (SD) of 7% for both the cis- and trans- isomers. Recoveries for CAAL in soil fortified at the 0.4 ng/g level averaged 88% with a SD of 10% for the cis- and 90% with a SD of 9% for the trans- isomers. Calculated limits of detection (LOD) for each CAAL isomer in surface water and soil were 0.02 ng/mL and 0.1 ng/g, respectively. Recoveries for CAAC in surface water fortified at the 0.05 ng/mL level averaged 89 and 90%, each with a SD of 6%, for the cis- and trans- isomers, respectively. Recoveries for CAAC in soil fortified at the 0.2 ng/g level averaged 83% with a SD of 11% for the cis- and 87% with a SD of 9% for the trans- isomers. Calculated LOD's for each CAAC isomer in surface water and soil were 0.009 ng/mL and 0.06 ng/g.