Rapid determination of sulfonamides in chicken using two-dimensional online cleanup mode with three columns coupled to liquid chromatography-tandem mass spectrometry.

A novel method based on online cleanup mode combined with liquid chromatography-tandem mass spectrometry (LC-MS/MS) was established. After an automated sample cleanup system with aqueous gel column, sulfonamides in chicken were detected in multiple reaction monitoring (MRM) mode. The total run time of the system, which included automated extraction, analytical chromatography and re-equilibration, was within 30 min. Different experimental processes containing extraction, purification, separation, and detection have been evaluated respectively to obtain optimized parameters. The developed method was fully validated and the efficient and superior performance of the developed method was demonstrated. The method produced linear results for all sulfonamides from 1 to 10 ng g-1 with a linearity >0.99. The intra-day precision of the method was <8.45% while the inter-day precision was <9.11%. The matrix effect was 77.5% to 105.1%. The recovery was in the range of 72.66% to 116.7% for all sulfonamides. The limit of quantitation in the chicken was 0.6 ng g-1 and the limit of detection was 0.2 ng g-1. Compared with traditional procedures, the automated sample clean-up strategy could significantly shorten the analysis time and offer higher detectability, with the advantage of sufficient sensitivity. Also, the use of gel chromatography column employed the water phase and reduced the organic reagent to achieve the level of green chemistry.

Acrylamide in thermal-processed carbohydrate-rich foods from Chinese market.

Acrylamide content in food market in China was determined with the goal to evaluate related health concern. In this survey, products of rice, potato corn, wheat as well as dried fruit slices and instant foods were analysed. All these types of thermal-processed carbohydrate-rich foods were frequently consumed in China. They were purchased from markets in Zhejiang province and analysed using a liquid chromatography tandem/mass spectrometry method. Acrylamide was detected in 94.3% of 105 investigated samples, ranging from 10 to 3649 µg/kg with an average value of 231 µg/kg and a median of 114 µg/kg. In this study, high levels were found in potato products (564 ± 285 µg/kg), corn products (524 ± 187 µg/kg) and instant foods (180 ± 35 µg/kg) while low levels were measured in rice products (82 ± 17 µg/kg), wheat products (96 ± 29 µg/kg) and dried fruit slices (83 ± 13 µg/kg).

Serum bisphenol A concentration and premature thelarche in female infants aged 4-month to 2-year.

OBJECTIVES: To estimate the association between serum bisphenol A and premature thelarche in female infants aged 4-mo to 2-y. METHODS: A total of 251 female infants (aged 4 mo to 2 y) with premature thelarche and 33 healthy age-matched control subjects were analyzed. All participants underwent physical examination and serum bisphenol A was measured by ultra-performance liquid chromatography tandem mass spectrometry. RESULTS: Serum bisphenol A concentration in the premature thelarche group (3.48 ng/ml, 95%CI: 0.09-140.26) was significantly higher than that in the control group (1.70 ng/ml, 95%CI: 0.06-51.78) (p = 0.039). There was no correlation between age and serum bisphenol A (BPA) level. Univariate logistic regression analysis showed that serum BPA concentration positively associated with premature thelarche, and the effect of BPA fell down as the age grew. CONCLUSIONS: This hospital-based study implied that there is an association between serum BPA concentrations and premature thelarche. Additionally, serum BPA levels were markedly higher in infants aged 4-mo to 2-y-old, raising a concern for public health authorities.