高效液相色谱-串联质谱法同时测定食用植物油中多种有机锡化合物

有机锡化合物已广泛应用于食品包装材料及其生产过程中,对人体健康存在着潜在的危害。特别是食用植物油因甘油三酯(脂肪)含量较高,约占植物油的95%以上,给分析检测带来较大的基体干扰。本文采用低温冷冻提取结合固相萃取技术,建立了高效液相色谱-串联质谱法同时测定食用植物油样品中二丁基二氯化锡、二苯基二氯化锡、三丁基氯化锡、三苯基氯化锡同时分析的方法。实验对比了甲醇、乙腈、乙醇三种有机萃取溶剂分别在低温冷冻提取和常规液液振荡提取条件下的提取效率,并考察了PSA、中性氧化铝、弗罗里硅土及活性炭四种净化材料对食用油提取液的净化效果。确定了食用油中有机锡化合物的最佳提取净化方案为:以10 m L甲醇为提取溶剂在低温冷冻条件下充分提取两次,并通过50 mg活性炭净化提取液。为评价该方法的准确性,对食用油样品进行三个不同水平的添加回收实验,各有机锡化合物的平均回收率在74.2%~99.5%之间,接近或优于现行国标及相关研究(70%~120%),可应用于菜籽油、花生油、芝麻油、大豆油、玉米油及调和油等不同基质的食用植物油中有机锡化合物的同时测定。

Determination of a Variety of Organotin Compounds in Edible Vegetable Oil by Liquid Chromatography-Tandem Mass Spectrometry

Micro-organisms are the main drivers of water biogeochemical cycle and the major player in energy metabolism, which are pivotal for maintaining diversity and stability of the water ecological systems. Aerobic anoxygenic phototrophic bacteria (AAPB), the important functional groups widespread in the water, can acquire energy from light and further affect the hydrochemical composition. The importance of AAPB is well recognized and in-depth studied. In order to study the relationship between the hydrochemical characteristics and the AAPB feedback effect in front of the Wulixia Reservoir dam, water samples from different layers were collected. Based on the stable carbon isotope of dissolved organic carbon and particulate organic carbon isotope composition, the distribution pattern of AAPB were measured by real-time PCR technology. Results show that the hydrochemical type of the front of reservoir dam water system was HCO₃^--Ca²⁺-Mg²⁺ type and poor-moderate eutrophication state during the sampling period. The results of dissolved oxygen, stable carbon isotope and the C/N showed that the main source of organic carbon was produced by microorganisms. The ratio of AAPB to total planktonic bacteria in the Wulixia Reservoir water was 1.33%-1.60%, and the variation degree of AAPB abundance was greater than that of the total planktonic bacteria abundance, which means that the AAPB feedback are more sensitive to the hydrochemical characteristics compared with that of total planktonic bacteria. The canonical correspondence analysis can reveal the relationship between hydrochemical composition and AAPB. CCA result showed that AAPB and total planktonic bacteria were strongly influenced by turbidity, which makes it possible to apply marine microbiological pump theory in karst reservoirs. Hydrochemical characteristics feedback on AAPB will improve understanding of the metabolic system of CO₂-H₂O-carbonate and micro-organisms.