Characterization of short- and medium-chain chlorinated paraffins in cereals and legumes from 19 Chinese provinces.

Short-chain chlorinated paraffins (SCCPs) were added to the Stockholm Convention Annex A in May 2017. China is the largest producer of chlorinated paraffins (CPs). CPs in the environment can be transferred to foodstuffs directly and through bioaccumulation and then ingested by humans. Cereals and legumes are important components of Chinese diets, so the risks posed by CPs in cereals and legumes should be of concern. 1710 cereal samples and 1710 legume samples from 19 Chinese provinces were pooled by type and province (giving 19 pooled cereal and 19 pooled legume samples). The SCCP and medium-chain chlorinated paraffin (MCCP) concentrations in the samples were determined by comprehensive two-dimensional gas chromatography tandem time-of-flight mass spectrometry (GC × GC-TOFMS). The mean SCCP concentrations in the cereal and legume samples were 343 and 328 ng g-1 wet weight (ww), respectively, and the mean MCCP concentrations were 213 and 184 ng g-1 ww, respectively. The dominant SCCP congener groups were C10Cl6-7 in cereals and C10Cl5-6 in legumes. The MCCP congener groups C14Cl6-7 were dominant in both cereals and legumes. The CP concentrations were higher in samples from eastern China than in samples from other regions. Risk assessments indicated that SCCPs and MCCPs in cereals and legumes do not pose strong risks to Chinese residents.