Organic waste products in agriculture - MONITORING the waste constituents phthalate esters in soil-crop system by gas chromatography and ion trap tandem mass spectrometry

Abstract

A method is described for monitoring phthalate esters in organic waste products, agricultural soil and crops. Solvent extraction, Ultra Turrax homogenisation and sonification were used to isolate the compounds from the sample matrices. Solid phase extraction was applied for purification, and gas chromatography with tandem mass spectrometry for identification. With the method, six phthalate esters were determined in different matrices. The detection limits were in the range of 1 to 10 ug kg-1 wet weight, except for DEHP, which had a detection limit approaching 100 ug kg-1 wet weight. Repeatabilities were from 5 to 20 % relative standard deviation. Recoveries were from 6 to 100 %, depending on the compound analysed. However, except for the polar phthalates DMP and DEP, the recoveries were above 70 %. The method feasibility was demonstrated in an investigation of the occurrence of phthalate esters in barley, rape, carrots, agricultural soil, aerobic and anaerobic sludge, household compost and pig manure.