Di(isononyl) cyclohexane-1,2-dicarboxylate (DINCH) is a high molecular weight plasticizer. It was developed for use in polyvinyl chloride plastics (PVC), largely as an alternative to di-(2-ethylhexyl) phthalate (DEHP) and di-isononyl phthalate (DiNP) (Crespo et al., 2007; EFSA, 2006). Because it is not chemically bound to the plastics, DINCH can be released into the environment during use, and can also migrate into foods or indoor environment where human exposure to DINCH can occurr.

The known metabolites of DINCH are cyclohexane-1,2-dicarboxylic monoisononyl ester (MINCH), cyclohexane-1,2-dicarboxylic mono hydroxyisononyl ester (OH-MINCH), cyclohexane-1,2-dicarboxylic mono oxoisononyl ester (oxo-MINCH), and cyclohexane-1,2-dicarboxylic mono carboxyisononyl ester (cx-MINCH) and cyclohexane-1,2-dicarboxylic acid (CHDA) (Koch et al., 2013). We want to identify which biomarker can accurately reflect the exposure to DINCH. We prepared 30 Korean urine by solid-phase extraction and analyzed 4 metabolites of DINCH using UHPLC-MS/MS.

Urinary median concentration (detection rate) of the 4 metabolites were as follows; CHDA 3.3 (100%), cx-MINCH ND (43%), OH-MINCH ND (33%), MINCH ND (10%). In recent study, DINCH was found the major pollutant in indoor dust. But most of the metabolites were not detected in human urine, except CHDA. This results suggest that CHDA might the most appropriate biomarker of exposure to DINCH.