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A rapid, specific, and sensitive method has been developed using molecularly imprinted polymers (MIPs) as solid-phase extraction sorbents for extraction of trace tetracycline antibiotics (TCs) in foodstuffs. MIPs were prepared by precipitation polymerization using tetracycline as the template. Under the optimal condition, the imprinting factors for MIPs were 4.1 (oxytetracycline), 7.0 (tetracycline), 7.4 (chlortetracycline), 7.7 (doxycycline), respectively. Furthermore, the performance of MIPs as solid-phase extraction sorbents was evaluated and high extraction efficiency of molecularly imprinted solid-phase extraction (MISPE) procedure was demonstrated. Compared with commercial sorbents, MISPE gave a better cleanup efficiency than C18 cartridge and a higher recovery than Oasis HLB cartridge. Finally, the method of liquid chromatography-tandem mass spectrometry coupled with molecular-imprinted solid-phase extraction was validated in real samples including lobster, duck, honey, and egg. The spiked recoveries of TCs ranged from 94.51% to 103.0%. The limits of detection were in the range of 0.1-0.3 microg kg(-1).

Organophosphate flame retardants (OPFRs), used as flame retardants and plasticizers, have been suggested to impair fetal growth and development in toxicological studies, but epidemiological data are extremely limited. This study was designed to explore whether prenatal exposure to OPFRs was associated with an increased risk of low birth weight (LBW) using a nested case-control design based on the ongoing prospective birth cohort in Wuhan, China. A total of 113 cases and 226 matched controls recruited from this cohort project in 2014−2016 were included. OPFR metabolite concentrations in maternal urine samples collected in the third trimester were determined, and birth outcomes were extracted from medical records. Compared with the lowest tertile of diphenyl phosphate (DPHP) concentrations, pregnant women with the highest tertile of DPHP had a 4.62-fold (95% confidence interval (CI): 1.72, 12.40) significantly increased risk for giving birth to LBW infants, with a significant dose−response relationship (p-trend < 0.01). After stratification by newborn sex, the significant positive association of DPHP levels with LBW risk was merely observed among female newborns. Our results suggest a positive association between maternal urinary DPHP concentrations and LBW risk for the first time, and the effect appears be sex-specific.

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