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Reference materials for quantitative determination of regulated heavy metals, such as Pb and Cd in electronic components, were designed and investigated in terms of stability and homogeneity. Reference materials with two concentration levels of heavy metals were prepared by spiking Pb and Cd compounds to epoxy molding compounds made by mixing silica powders and epoxy resin. The concentration changes of the reference materials during stability test for 1 a were not observed. In the homogeneity assessment, the as-prepared reference materials were studied by using three different analytical tools, inductively coupled plasma atomic emission spectrometry (ICP-AES), X-ray fluoroescence spectrometry (XRF) and laser ablation ICP mass. The results show different homogeneities by the characteristics of analytical tools and the materials. 相似文献
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目的 建立简便和快速地萃取西红柿中六种三嗪类除草剂的方法。方法 首先, 西红柿中三嗪类除草剂通过动态微波辅助萃取法进行萃取之后, 利用盐析液液萃取法对萃取物进行快速的富集和净化; 之后, 将获得的萃取物用氮气吹干, 用流动相定容至0.5 mL; 最后, 采用高效液相色谱-质谱仪对萃取物进行分析。结果 实验中对影响动态微波辅助萃取和盐析液液萃取萃取效率的实验条件进行了优化, 最优的实验条件为: 萃取剂为70%乙腈-水溶液, 微波萃取功率为350 W, 微波萃取时间为7 min, 萃取剂流速为1.0 mL/min, 萃取液pH值为8, 盐析盐为醋酸铵, 用量为2.0 g。六种三嗪类除草剂在1~1000 ng/mL范围内成线性关系, 相关系数为0.995~0.998; 检出限为0.08~0.33 ng/g; 方法的回收率为68%~104%, 相对标准偏差为5.0%~7.3%。结论 该方法被成功应用于西红柿中三嗪类除草剂的检测, 结果令人满意。 相似文献
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低分子量壳聚糖制备与应用 总被引:13,自引:0,他引:13
该文介绍自然界蕴藏量极为丰富绿色生物材料甲壳素脱乙酰化产物-壳聚糖降解产物壳低聚糖的制备、功能性、应用及发展前景。 相似文献
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lignan constituents in Schisandra Chinensis (Turcz.) Baill. were investigated using electrospray ionization multi-stage tandem mass spectrometry (ESI-MSn). Four compounds in Schisandra chinensis (Turcz.) Baill. were observed in the positive mode. The experimental results demonstrate that the ESI-MSn can provide the information of the relative molecular mass and chemical structure of the compounds. 相似文献
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硫磷酯高效液相色谱分析 总被引:1,自引:1,他引:0
采用Kromasil C18反相柱为色谱柱,乙睛:水=65:35(v/v)为流动相,紫外检测器在210nm对农药乐果中间体-硫磷酯进行高效液相色谱分离和测定。其线性相关系数为0.9999,变异系数为0.1%,回收率为99.4%~100.4%。 相似文献
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氧化矿捕收剂的增效剂 总被引:2,自引:1,他引:2
工业上广泛应用的氧化矿捕收仍以脂肪酸类、黄药类及其衍生物为主,羟肟酸也是一类成功的捕收剂。增效剂的引入可改善捕收剂的性能。用一些本身具有一定捕收剂功能的药剂,或者毫无捕收剂性能的表达活性剂、有机及无机化合物作增效剂,预先或与捕收剂同时处理矿物,会获得令人满意的浮选效果。 相似文献