受激光子回波在阵列天线波束合成中的应用研究

由于孔径效应和孔径度越时间的限制,使得传统的相控阵雷达难以实现大角度扫描和大的信号瞬时带宽.把受激光子回波技术应用于波束合成,可以克服这一难题.介绍了基于受激光子回波的光学真实延时实现原理,并分析了其在阵列天线波束合成中的应用,阐述了波束合成的实现方法.     

固相萃取-高效液相色谱法测定畜禽肉中复合硝基酚钠残留

通过碱性溶液提取,再用正己烷萃取除去脂肪,用乙酸调p H为酸性条件后用乙酸乙酯-异丙醇反萃取,浓缩后再通过混合阴离子固相萃取柱净化,最后采用高效液相色谱分离检测。结果:三种复合硝基酚钠组分在0.05¹.0μg/m L范围内其浓度与峰面积呈线性,相关系数均可达到0.999;通过萃取、反萃取以及固相萃取等多种手段净化,样品基质几乎无干扰,检出限可达到0.003⁰.005 mg/kg;通过对0.25、0.5、1.0μg进行加标测试,其回收率在81%⁹5%之间,相对标准偏差均小于10%。      

固相萃取-高效液相色谱法测定某水库型水源地微囊藻毒素

采用优化的固相萃取一高效液相色谱法对某水库型水源地微囊藻毒素污染进行了为期1年的监测,同时测定了相关的水质指标和藻类种群结构。结果表明：该水库在春末和夏、秋季检出了3种微囊藻毒索（MC—YR、MC—RR、MC—LR）,以MC—YR为主,夏季是藻毒素污染的高峰时段,其浓度与水库环境条件、藻类生物量有密切的关系。     

超高压液相色谱-串联质谱法检测猪肉中玉米赤霉醇类物质

目的 建立猪肉中6种玉米赤霉醇类物质(α-玉米赤霉醇、β-玉米赤霉醇、α-玉米赤霉烯醇、β-玉米赤霉烯醇、玉米赤霉酮和玉米赤霉烯酮)的超高压液相色谱-串联质谱(UPLC-MS/MS)检测方法。方法 样品经β-葡萄糖苷酶/硫酸酯酶酶解, 无水乙醚萃取, 再经氢氧化钠溶液液-液分配, 最后通过HLB固相萃取柱富集净化, UPLC-MS/MS检测, 基质匹配外标标准曲线法定量。结果 6种玉米赤霉醇类物质的线性范围为1.0~250 μg/L, 相关系数r＞0.990。当取样量为5.0 g时, 6种玉米赤霉醇类物质检出限为0.4 μg/kg。3个不同水平(添加1.0、5.0、20 μg/kg)的加标平均回收率为66.0%~79.5%, 相对标准偏差不大于10%。结论 所建立的方法具有较好的回收率和精密度, 准确度和灵敏度高, 符合猪肉中玉米赤霉醇类物质痕量的检测要求, 为大通量样品的食品安全检测提供更灵敏、高效的技术支持。     

固相萃取辅助提取-气相色谱-质谱分析烟熏腊猪肉香气成分

采用固相萃取辅助提取中国西南地区传统食品-烟熏腊猪肉的香气成分,用气相色谱法以邻二氯苯为内标对提取的烟熏腊猪肉香气成分进行定量分析,用气相色谱-质谱联用法对提取的烟熏腊猪肉香气成分进行定性分析。共鉴定出29个化合物,烟熏腊猪肉的重要香味成分有:2,5-二苯基-3-(2-呋喃甲酰基)吡咯、二苯胺、苯并噻唑、乙酰苯酚酯、对甲苯酚、3-乙基苯酚、4-乙基愈创木酚、对-甲基-2,6-二叔丁基苯酚、硬脂醛、α-异佛尔酮、2-甲基-1-十六醇、2,6-二叔丁基-4-羟基-4-甲基-2,5-环己二烯-1-酮等。     

固相萃取高效液相色谱法同时测定五仁醇浸膏中的5种木脂素

建立了五仁醇浸膏中5种木质素（五味子醇甲、五味子醇乙、五味子脂甲、五味子甲素和五味子乙素）的快速检测方法,并采用固相萃取高效液相色谱法对其进行了检测.结果显示：五味子醇甲、五味子醇乙、五味子脂甲、五味子甲素和五味子乙素进样量分别在0.048 8-2.44、0.040 8-2.04、0.049 6-2.48、0.036 0-1.80和0.048 0-2.40μg范围内具有良好的线性关系（R^2≤0.999 8）;平均加样回收率分别为101.24%、99.52%、103.72%、98.66%和98.08%,RSD≤1.62%.实验表明,固相萃取-高效液相色谱法具有简便、准确、稳定、灵敏度高、重现性好等优点,可用于五仁醇浸膏的质量控制.     

Monitoring survey of patulin in a variety of fruit-based products using a sensitive UHPLC–MS/MS analytical procedure

The mycotoxin patulin is known to be the predominant natural contaminant of apples, apple-based products and a variety of other fruits. Because of its high incidence and harmful health effects, patulin is included with mycotoxins, which are strictly monitored. In this study, a sensitive and reliable ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC–MS/MS) method was developed and validated for determination of patulin in a variety of fruit matrices. A combination of the QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) procedure along with a solid phase extraction (SPE) clean-up strategy enabled an effective removal of sample matrix and pre-concentration of patulin. This resulted in low limits of quantification ranging from 1 to 2.5 μg/kg, depending on fruit type. In our study, quantification of patulin was based on a stable isotope dilution assay (SIDA) using ¹³C₇-patulin as the internal standard. Data showed that the procedure described, in combination with neat solvent internal calibration, can be used for accurate quantification of patulin regardless the type of fruit. Although the SIDA method allowed omission of matrix-matched calibration, matrix-effects were estimated in order to assess suppression of the patulin signal caused by a variety of fruit samples. The method was fully validated for apples, apple baby food, apple juice, peaches, strawberries and blueberries. The recovery values were in the range from 92 to 109%. Repeatability of the method was below 10% for all tested matrices. The method was applied to the monitoring of patulin in 135 samples of fresh fruits and fruit products and can also be used as an efficient tool for routine monitoring of this contaminant in a variety of fruit-based foods.     

液相安培法检测鳗鱼中的磺胺类药物

本文建立了液相色谱安培检测鳗鱼中常用8种磺胺检测方法,采用甲醇:磷酸盐缓冲液(pH=3)梯度淋洗,反相C18分离.样品采用乙腈提取后,正己烷脱脂,用Oasis MCX、MAX小柱净化后,采用玻碳电极直流安培1.3V检测.线性范围为0.05-100μg/mL,分别做3个浓度的添加回收,方法回收率在52.8～102.0%之间,方法精密度在0.8～4.6%之间,方法定量限为0.5-4μg/kg.     

SPE-联系数物元算法的进展与应用

首先对SPE中联系数物元算法进行拓广,然后讨论它在信息分析以及商战中的应用.