Exposure Risk Assessment for Dietary Cyanamide in Grape Based on Residual Characteristics in Producing Areas of China.

The evaluation of short- and long-term exposure risks for different dietary consumption populations is meaningful for the health maintenance of residents and the sustainable development of our ecosystem, based on the residual characteristics of cyanamide in the main producing areas of grape across China. A rapid and effective analytical method was developed to trace cyanamide in grapes in this study. Target pesticide was extracted with acetonitrile in samples, then purified by dispersive solid phase extraction, and finally determined using ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). The mean recoveries and relative standard deviations (RSD) of cyanamide were 85% ~92% and 3.3% ~10.5% in the grape matrix, respectively. The retention time (RT) for cyanamide was 1.2 min, and the limit of quantification (LOQ) was 0.001 mg·kg^-1. Cyanamide could be stored stably for 184 d at least in grape samples in the frozen under dark conditions, with the degradation rates of 13.9% ~ 24.1%. The terminal magnitude of cyanamide ranged from 0.001 to 0.003 mg·kg^-1, and the supervised trials median residue (STMR) was of 0.002 mg·kg^-1. The highest residue (HR) of 0.003 mg·kg^-1 was lower than the maximum residue limit (MRL) of 0.05 mg·kg^-1, which was established by China and other countries. The acute risks of cyanamide for dietary grapes were from 1.600% to 25.346%, and the children suffered from the worst exposures (ARfD%, 25.346%), followed by the general population (ARfD%, 3.623%) and the women of childbearing age (ARfD%, 1.600%). The chronic dietary risks were between 0.290% and 4.275% for all of registered crops, including cherries, kiwi fruit and grapes. The exposure risks for urban residents were significantly higher than that of the rural residents ( P<0.05), and the most serious dietary risks were observed in children aged 2 ~6 years with ADI% of 2.763% ~ 4.275%. None of significant differences of chronic risks were obtained between genders of populations (P>0.05). Despite both dietary exposure risks of cyanamide within acceptable levels, the potential hazards amplification should be continuously assessed, given the increasing application and cumulative effects by multi-crops and multi-modes exposures in the biological chain, especially for the susceptible urban children. [ABSTRACT FROM AUTHOR]