Determination of hexahydrophthalic and methylhexahydrophthalic acids in urine by gas chromatography-negative-ion chemical-ionisation mass spectrometry
A method for determining hexahydrophthalic (HHP acid) and methylhexahydrophthalic acids (MHHP acid) from human urine was developed. These acids are metabolites of the highly sensitising hexahydrophthalic anhydride and methylhexahydrophthalic anhydride. The acids were purified from urine by liquid-solid extraction and derivatised with pentafluorobenzyl bromide to the corresponding esters. These wer