盐析辅助分散液液微萃取毛细管电泳测定口服液中甜味剂和防腐剂

目的 采用盐析辅助分散液液微萃取(SADLLME)-大体积样品堆积(LVSS)-毛细管电泳(CE)法测定阿斯巴甜、糖精、安赛蜜三种甜味剂以及苯甲酸、山梨酸两种防腐剂。方法 将待测溶液进行盐析液液微萃取处理后进行CE分析测定,设定电泳条件为：进样压力50 mbar,进样时间为 120 s,正常极性下分离电压为 20 kv,检测波长为 214 nm,分离温度为 25 °C。 结果 该方法在0.05~1.00 μg/mL范围内线性关系良好,最低检测限为2.5 ng/mL~10 ng/mL。萃取重现性良好(RSD小于10 ％,n=5)。待测组分富集倍数达到657~1674,富集效果良好。把该方法应用于不同种类口服液进行食品添加剂含量的测定,均获得了满意的结果。结论 实验表明使用微萃取与在线富集结合的手段更为高效、快速,能获得更高的富集倍数,成为提高毛细管电泳灵敏度的一种可靠方法。     

Contents of methyl-, ethyl-, propyl-, butyl- and benzylparaben in cosmetic products

The contents of methyl-, ethyl-, propyl-, butyl- and benzylparaben in 215 cosmetic products have been determined to elucidate the concentration and frequency of use of these parabens in cosmetic products, and to monitor whether the products complied with the Danish and EEC regulations. The results showed that 77% of the products investigated contained 0.01%–0.87% parabens. Nearly all (99%) of the leave-on cosmetics and 77% of rinse-off cosmetics were found to contain parabens. A maximum of 0.32% methyl- and propylparaben, 0.19% ethylparaben, and 0.07% butyl- and benzylparaben were present in paraben-positive cosmetics. A preferential use of methyl-/ethyl-/propyl-/butyl-/benzylparaben in various groups of cosmetic products was revealed.     

Monitoring levels of preservative sensitivity in Europe. A 10-year overview (1991-2000)

A 10-year multicentre analysis of the frequency of sensitivity to common preservatives collected in 16 centres in 11 countries has shown stable but persisting high levels of sensitivity to formaldehyde and 5-chloro-2-methyl-4-isothiazolin-3-one + 2-methyl-4-isothiazolin-3-one (MCI/MI). It has also revealed a significant increase in the level of reactivity to methyldibromoglutaronitrile (MDBGN) from 0.7% in 1991 to 3.5% in 2000. The current high level of sensitivity to MDBGN requires an urgent safety re-evaluation and risk assessment update along with consideration of immediate lowering of use concentrations, especially in leave-on products.