离子色谱-质谱联用法测定食品中溴酸盐

建立离子色谱-质谱(IC-MS)联用方法检测食品中溴酸盐。不同食品样品中的BrO3-离子经水提取,经过C18和Ag柱除杂质,再经离子色谱分离,最后在选择反应监测模式(SRM)下进行检测,外标法定量。BrO3-质量浓度在0.1~100μg/L内具有良好的线性关系(R2=0.999 9),检出限为1.0μg/kg,定量限为4.0μg/kg。加标回收率为92.7%~104.2%,精密度RSD5%,该方法的灵敏度、准确度和精密度均符合相关的技术要求,适用于食品中痕量BrO3-分析的要求。     

离子色谱-质谱联用法测定食品中溴酸盐

建立离子色谱-质谱（IC-MS）联用方法检测食品中溴酸盐。不同食品样品中的BrO3-离子经水提取,经过C18和Ag柱除杂质,再经离子色谱分离,最后在选择反应监测模式（SRM）下进行检测,外标法定量。 BrO3-质量浓度在0.1~100μg/L内具有良好的线性关系（R2=0.9999）,检出限为1.0μg/kg,定量限为4.0μg/kg。加标回收率为92.7%~104.2%,精密度RSD<5%,该方法的灵敏度、准确度和精密度均符合相关的技术要求,适用于食品中痕量BrO3-分析的要求。     

用反相离子色谱法测定大麦草片剂中VB_1的含量

建立大麦草片剂中VB1的反相离子色谱的测定方法。测定方法为:色谱柱:UltimateTM column XB-C18,5μm,4.6 mm×250 mm;流动相:0.05 mol/L乙酸钠溶液和甲醇的体积比为60∶40;流速:1.0 mL/min;检测波长:激发波长375 nm,发射波长435 nm。结果表明,VB1质量为0.000 1～0.000 5μg,线性关系良好(R2=0.999 8),平均回收率为99.44%。该方法简单、专属性强、灵敏度高,适用于大麦草片剂中VB1的含量测定。     

大体积进样GC/MS选择离子法检测茶叶中有机氯农药DDT

建立了茶叶中有机氯农药DDT残留量的大体积进样GC/MS选择离子分析方法。样品以丙酮提取,提取液以浓硫酸净化,采用DB—5MS石英毛细管柱,大体积进样,选择离子监测检测市售茶叶中DDT残留量,检出限比常规不分流检出限提高2个数量级,最低检测浓度约为0.8μg/kg。     

Determination of Phytic Acid in Cottonseed Kernels by Ion Chromatography

Cottonseed meal is an important plant protein resource of feed industry and breeding industry, although it contains many antinutritional factors. Phytic acid, as one of the mainly antinutritional factor, cannot be digested easily by monogastric animals, such as fowls and pigs, consequently results in the decreased bio-availability of material elements and leads to the environment pollution by the phytate in excreta. Thus far, study of breeding cottons containing low phytic acid gradually becomes the hotspot, and the method of fully extracting phytic acid from cotton seeds and precise measurement is becoming more and more important and necessary. A new method for the rapid extraction and determination of phytic acid in cottonseed kernels by ion chromatography was developed in this study. After the diethyl ether treatment of dry cottonseed kernel powder, the samples were suspended in 10ml 0.66 mol·L^－1 HCl and boiled for 1 hour. Then the samples were shaken at 4 ℃ for 12 hours and centrifuged. The supernatant was diluted and purified for loading. To analyze the sample, DIONEX ICS-2000 ion chromatography, AG11-HC Guard (4 mm×50 mm) protection column and AG11-HC Guard (4 mm×250 mm) separation column were used in controlled conditions (washing buffer: 30.0 mmol·L^－1 KOH; ream speed: 1.0 mL·min^－1; collecting time: 25 min; 75 mA current; temperature: 30 ℃; loading amount: 20 μL). The results showed that R2 of linear regression is 0.999, which means the regression relation is great. In addition, the standard deviations of all the indexes are within 5% and the average recovery rate is 98.64%-102.31%. The detection limit, showing the minimum detectable concentration of analyte in the sample, is 0.059 μg·mL^－1, and the quantitation limit, showing the minimum amount of analyte in a sample can be quantitatively determined, is 0.196 μg·mL^－1. This method is easy and accurate with great reproducibility, showing a strong application value.     

Microstructure Characteristics Analysis of Particles in Drinking Water Treatment Effluents by Activated Carbon

Scanning Electron Microscope and Energy Dispersive Analysis (SEM EDS) were used to study the elements of particles in drinking water treatment effluents, to conduct the distribution characteristics of particles and distribution probability of main elements, and to analyse the possible structure of individual element in the Granular Activated Carbon(GAC) effluents particles. It was indicated that there were more elements in particles at GAC inlet and outlet, in which the major elements were Ca、Fe、Al 、Si 、C、O. And the concentration of non metal elements was absolutely higher than that of metal elements. The shapes of particles were various, in which most of them were irregular and very few were baculiform, spherical or flocculent. The molar ratio of (C+O) to (Ca+Fe+Al+Mg) in particles had a wide range, from 1.0 to 40, in eight samples, in which ratios of two samples were 1.0-3.0 and five were over 7.0.     

固相萃取离子色谱法快速测定烟草中钾、钠、钙、镁和氨的研究

采用带固相萃取净化功能的样品萃取瓶超声萃取烟草样品,样品萃取液用石墨化炭黑球固相萃取净化。然后以IonPacCS12A阳离子交换色谱柱(3 ′ 150 mm,5 μm)为固定相,30 mM甲基磺酸为流动相,淋洗液流速1.0 mL/min,K+、Na+、Mg2+、Ca2+、和NH4+ 5种阳离子在6.0 min内可达到完全分离。采用自主设计的样品萃取瓶,可不经样品转移就完成样品的萃取、净化和过滤。和常规方法相比,操作流程得到简化,效率大幅度提高,灵敏度和回收率高、精密度好。为基因编辑素材钾、钠、钙、镁和氨的快速测定提供了高通量分析方法。     

微波处理-气相色谱法测定洋葱中氟虫腈残留

通过优化微波处理和气相色谱分析条件,建立洋葱中氟虫腈残留的微波处理-气相色谱测定方法。针对目标物化学性质和干扰物情况,样品经微波处理后,用乙腈提取,进气相色谱测定,基质外标法进行定量分析。结果表明:洋葱基质中,氟虫腈在0.0005~0.05μg/mL范围内线性关系较好(R2=0.9982),方法检出限为0.0015 mg/kg;氟虫腈在0.002、0.020、0.050 mg/kg三个添加水平下加标回收率为77.5%~123.5%,相对标准偏差为3.12%~7.98%,符合食品安全国家标准GB 2763—2019中残留检测限量的要求。该法准确、快速、灵敏,对研究富含蒜氨酸的食品中氟虫腈的检测具有一定的应用和参考价值。     

静态顶空气相色谱法测定蜜柚中乙醇和乙醛含量

研究与优化了静态顶空气相色谱法测定蜜柚中乙醇和乙醛含量的色谱条件,其最佳平衡温度为80℃,平衡时间为45min,乙醇和乙醛的平均回收率分别为103.29%和95.58%;应用该方法研究了不同膜包装的蜜柚果实冷藏期间乙醇含量的变化情况,结果表明,用不同厚度的聚乙烯膜包装,随膜厚度的增加,蜜柚果实乙醇含量明显升高,对果肉风味的影响加大,以微孔膜包装的蜜柚果实贮藏效果最好,可保持其良好的风味品质。     

静态顶空气相色谱法快速测定葡萄中乙醇和乙醛含量的研究

介绍了建立静态顶空气相色谱法测定贮藏后玫瑰香葡萄中乙醇、乙醛含量的方法。对顶空进样条件进行了优化,顶空温度65℃,恒温加热时间为35min最优。此方法的乙醇、乙醛检测限分别达到0.02mg/kg和0.03mg/kg,其回收率分别为98.7%和95.6%,与其它测定方法相比具有操作简单,分析快速,结果准确等优点。     

加味逍遥片中福美双和代森锰锌残留量气相色谱法的建立

为了探究样品中二硫代氨基甲酸酯类农药污染情况及其在加工过程中的转移情况,本研究通过优化样品前处理条件及色谱条件后,建立了测定加味逍遥片中代森锰锌及福美双的残留量的气相色谱-火焰光度(GC-FPD)法。二硫代氨基甲酸酯类农药在含氯化亚锡的盐酸介质中反应生成CS₂,采用顶空进样法精密度不佳,且顶空气体中存在高浓度HCl气体会造成气相色谱进样部件腐蚀,故本研究将顶空进样改为溶液进样,使用异辛烷对检测指标进行提取。实验证明此方法在0.02~2.0 μg/mL浓度范围内线性关系良好,相关系数R值大于0.99。在5、20、100 μg/kg三水平进行加样回收率考察,代森锰锌及福美双平均回收率在99%~115%之间,RSD均小于2.0%,符合痕量农药残留的检测要求。对加味逍遥片及其处方中药材、提取物共计36批次进行检测,结果表明样品中CS₂残留量符合欧洲药典及中国食品安全标准中相关残留限量规定。本研究建立的加味逍遥片中代森锰锌及福美双的GC检测方法,其灵敏度高,准确、可靠,可用于加味逍遥片及生产中间提取物的农药残留监控。     

改良QuEChERS方法结合气相色谱测定红甜菜中20种农药残留

建立了改良的QuEChERS法结合气相色谱-电子捕获检测器用于红甜菜中20种农药残留的联合测定方法。样品中农药残留以乙腈作为提取溶剂,多壁碳纳米管分散固相萃取去除杂质,过滤后经RTX-1色谱柱分离,GC-ECD检测,外标法定量。探讨了气相色谱的程序升温条件,考察了不同提取溶剂及不同的净化方法对检测结果的影响。结果表明：在优化的色谱条件下,20种农药在0.01~0.50 mg/L（莠去津为0.03~0.50 mg/L）范围内线性关系良好,相关系数(R²)均大于0.99,并且得到很好的分离;乙腈与样品的比例为1:2,多壁碳纳米管用量为10 mg的前处理条件下,红甜菜样品在3个浓度的平均回收率为62.0%~116.5%之间,相对标准偏差为1.9%~10.9%,检出限为0.12 µg/L~0.063 mg/L,定量限为0.4 µg/L~0.21 mg/L。该方法操作简单、快速、准确,适用于红甜菜中有机氯及拟除虫菊酯类多农药残留的检测。