离子阱GC-MS-MS检测鼠药中的毒鼠强

建立了离子阱气相色谱-串级质谱（MS—MS）检测鼠药中毒鼠强的方法。测定毒鼠强的线性范围为0．2～5．0mg／L,线性相关系数为0．9984,检出限为0．0013mg／kg,回收率为76．1％～116．7％,测定结果的相对标准偏差为6．1％（n=6）。同时利用二级质谱分析了毒鼠强裂解规律,该法对毒鼠强具有良好的确证性。     

6-氯吲哚酮的含量测定研究

以无水乙醇作为溶剂,用紫外分光光度法测定盐酸齐拉西酮的重要中间体6-氯吲哚酮的含量．测得6-吲哚酮对照品溶液浓度在0．0048～0．0200mg／mL范围之内线性关系良好,其线性方程为Y=41．484X＋0．007（R^2=0．9994）．平均回收率为99．11％,RSD为0．53％（n=6）,结果说明方法简便、灵敏、准确,重现性好．     

气相色谱法测定羟乙基乙二胺中的乙二胺含量

采用毛细管气相色谱内标法测定羟乙基乙二胺中的乙二胺含量．结果表明。乙二胺在0．12．0ms／mL范围内的线性关系良好（r=0．9997）,检出限为0．02m/mL,方法的精密度RSD为1．7％（n=6）,加标回收率在95％～101％．     

用GC-FID和GC-TOF-MS方法分析α-硫辛酸中有机溶剂残留量

采用GC-TOF-MS鉴定残留有机溶剂,以HP-5毛细管柱为分离柱,FID为检测器,正辛醇为溶剂,外标法进行定量。乙醚、异丙醚的线性范围分别为34．4～344．0μg／mL（r=0．9999）,23．0～230．0μg／mL（r=0．9999）;方法精密度和稳定性试验RSD（n=6）均〈1％;平均回收率范围98．1％～100．7％,RSD0．75～2．7％;检出限分别为0．1,0．08μg／mL。     

ICP-AES法测定钢中的铈

建立了离子体发射光谱仪测定钢中铈元素的方法。为消除共存元素对铈分析游线的光谱干扰,选择Ce413．380nm作为分析线,铈含量在0．005％-0．50％之间工作曲线线性良好。对于含量范围在0．005％-0．10％的铈元素,回收率为85．6％-12．5％,测定结果的相对标准偏差小于9．74％（n=8）;对于含量范围在0．10％-0．50％的铈元素,回收率为99．5％-103．0％,测定结果的相对标准偏差小于3．52％（n=8）。该方法适宜钢中含量范围在O．005％-0．50％的铈元素的测定。     

青海省唐古特铁线莲质量控制标准的研究

目的对青海省唐古特铁线莲质量控制标准进行研究。方法采用薄层色谱法对唐古特铁线莲进行定性鉴定,展开剂为氯仿与丙酮（95：5）,显色剂为10％硫酸甲醇;采用HPLC（Lc-2010HT）法测定唐古特铁线莲中齐墩果酸的含量,色谱柱为PhenomenexLunaCt8（250mm×4．6mm,5Ixm）,流动相为y（乙腈）＋V（0．2％磷酸水溶液）=35＋65,流量为1mL／min,柱温为室温（25℃）,检测波长为205nm。结果薄层色谱鉴定中,供试品色谱与对照品色谱相应的位置上,显示出相同颜色的荧光斑点;齐墩果酸在0．0233—0,7000mg／mL范围内呈良好的线性关系,线性回归方程为Y=2×10-6＋360803,r。=0．9917,RSD为1．61％,并对青海省野生和栽培唐古特铁线莲中齐墩果酸进行了定量分析,结果显示前者平均值为0．1184％、RSD为2．5113％,后者平均值为0．0651％、RSD为2．92％。结论该法操作简单、快速、准确、灵敏、重现性好,可有效控制青海省唐古特铁线莲的质量。     

高效液相色谱-蒸发光散射检测器测定食品中胆固醇含量

建立了可满足各类食品（包括动物性食品、动植物混合食品）中胆固醇的HPLC—ELSD快速测定方法。样品经50％（w）KQH直接皂化和石油醚萃取后进行色谱分析。色i普柱为ODS柱,流动相为乙醇和乙脯,通过优化梯度洗脱条件,在20min内实现了胆固醇与干扰物质（如植物甾醇）的有效分离,分离度月大于1．5。胆固醇色谱峰面积的自然对数与浓度的自然对数呈良好的线性关系（r〉0．9996）,检出限（LOD）为0.20μg（S／N=3）,定量下限（LOQ）为0．56μg（S／N=10）,回收率为93％-96％（n=6）,重复性RSD〈3．0％（n=6）。     

微波消解-ICP—MS法同时测定砖茶中的铅、铜、铬和16种稀土元素

采用微波消解处理样品,以电感耦合等离子质谱（ICP-MS）法同时测定砖茶中的铅、铜、铬和16种稀土元素。采用外标法绘制校准曲线,分析了茶叶国家标准物质GBW 10016,测定值与标准值吻合。检出限为0．055-0．765μg／蚝,样品测定结果的相对标准偏差为0．2％～4．7％（n=6）。用加标回收的方法评价了该方法的准确性,回收率为88．0％-102．7％。该方法测定结果与电热板湿法消解前处理测定结果相比差异不显著。     

凝胶渗透色谱-气相色谱质谱法测定：花生中6种除草剂农药残留

建立了凝胶渗透色谱一气相色谱质谱（GPC～GC=MS）法测定花生中6种除草剂（氟乐灵、异恶草酮、甲草胺、二甲戊乐灵、乙氧氟草醚、喹禾灵）农药残留的方法。样品经乙腈提取,氨基固相萃取柱和凝胶渗透色谱净化,在选择离子扫描（SIM）模式下进行气相色谱质谱法测定,外标法定量。6种除草剂浓度在0．02-1．00mg／L范围内与色谱峰面积呈良好的线性,线性相关系数为O．9949～0．9998,添加回收率为77．8％-101．6％,测定结果的相对标准偏差为4．4％～11．4％（月=5）,方法的检出限为0．1～1．3μg／kg。     

微波消解ICP-MS法测定广西北部湾海鸭蛋中硒和锗的含量

以硝酸-过氧化氢（体积比为5：3）混合溶液为消解剂,微波消解法处理海鸭蛋样品,采用电感耦合等离子体质谱法测定样品溶液中的硒和锗的含量。选择适合的同位素元素,运用碰撞室技术（CCT）降低多原子离子对元素硒、锗的干扰,用钇作为在线内标。硒、锗工作曲线的线性范围均为0．0-100．0ng／mL,相关系数r=0．9996;硒、锗的检出限分别为1．1,0．15ng／mL,测定结果的相对标准偏差分别为4．78％,5．70％（n=6）,加标回收率为92．2％-104．0％。用该法测定国家标准物质黄鱼（GBW08573）中硒的含量,测定值在标称值范围内。     

高效液相色谱法测定农药拌种剂中的马钱子碱

 采用高效液相色谱法测定了农药拌种剂中马钱子碱的含量。色谱柱为 Spherisorb C18柱,以甲醇-水-溴代十六烷基三甲铵溶液(质量比为88∶12∶0.04）为流动相,检测波长为254 nm。在上述条件下,待测组分与其他组分达到基线分离。方法的线性范围为0.01 g/L～0.25 g/L,相关系数为0.999 7,回归方程为A=11 485 814ρ＋21 229,相对标准偏差为1.2%（n=11）。方法的稳定性高,重现性好,操作简便迅速,结果准确,是控制农药拌种剂内在质量的新方法。     

Comparison of linseed (Linum usitatissimum L.) genotypes with respect to the content of polyunsaturated fatty acids

The aim of our work was to characterize linseed (Linum usitatissimum L.) genotypes divided into groups with high and low content of alpha-linolenic acid (ALA). Out of 32 linseed genotypes, 68.75 % represented high alpha-linolenic genotypes and 31.25 % were genotypes with low ALA content. Proportional representation of fatty acids was realized according to the norm (Czech Office for Standards, Metrology and Testing, 1994). Oil content was analyzed according to the internal methodology of Agritec Ltd., based on the norm (Czech Office for Standards, Metrology and Testing, 2011). The content of total fat ranged from 36.22 % to 46.35 %, that of ALA from 1.10 % to 65.20 %, and that of linoleic acid (LA) from 11.10 % to 75.00 % in the analyzed seed samples within all groups. The genotypes were divided also according to the seed color and a linear correlation between all three parameters within these groups was observed. Negative linear dependence was confirmed between parameters; ALA and LA content in the groups: high ALA brown seed (p < 0.0001; correlation coefficient (r) = ?0.70), and high ALA yellow seed (p < 0.001; r = ?0.36). Also, positive linear dependence between the total fat and the LA content in the groups: low ALA brown seed (p < 0.001; r = 0.34); low ALA yellow seed (p < 0.0001; r = 0.62), was found.     

Switch-on fluorescence sensor for ascorbic acid detection based on MoS2 quantum dots-MnO2 nanosheets system and its application in fruit samples

In this work,molybdenum disulfide quantum dots(MoS_2 QDs) were firstly prepared by hydrothermal method using sodium molybdate and glutathione as precursors,and applied in ascorbic acid detection.When joining MnO_2 nanosheets into MoS_2 QDs solution,they produced an obvious fluorescence quenching,which should be due to inner filter effect(IFE).Meanwhile,the fluorescent probe was formed,Interestingly,we found that this quenching phenomenon disappeared with the addition of ascorbic acid,In other words,the fluorescence gradually restored.This recovery phenomenon is mainly due to the reduction effect of ascorbic acid for MnO_2 nanosheets.Under the optimum conditions,the limit of detection(LOD) of 39 nmol/L for ascorbic acid was achieved with a linear range of 0.33-5.00 μmol/L.The repeatability was better than 5.0% for ascorbic acid in both standard and fruit samples(n = 3).Moreover,the as-fabricated fluorescent sensing system was successfully employed to detect the ascorbic acid levels in hawthorn and jujube with satisfactory results.     

高效液相色谱法测定我国北方红枣中环磷酸腺苷的含量

采用高效液相色谱（HPLC）法准确测定环磷酸腺苷（cAMP）含量,并对我国北方红枣中的cAMP含量进行测定.以Hibar ODS-C18（250 mm×4.6 mm,5 μm）为色谱柱,流动相为甲醇:2%醋酸（体积比为5:95）,流速0.5 mL/min,检测器为Waters 996,检测温度为25℃,检测波长为254 nm.标准曲线在0.1~1.0 mg/mL范围内线性良好,加标回收率为102.1%,相对标准误差为0.63%.同时,采用的条件能将红枣中cAMP与其他成分的峰完全分离,发现不同产地的红枣中cAMP含量不同,新疆地区所产红枣的质量分数最高,能达到372 μg/g.方法可准确测定我国北方红枣中环磷酸腺苷的含量,灵敏度高,可为红枣中cAMP的提取和高值化利用提供重要的技术依据.     

Residue analysis and risk assessment of tebuconazole in jujube (Ziziphus jujuba Mill)

In this study, a sensitive and reliable analytical method, based on a modified Quick, Easy, Cheap, Effective, Rugged and Safe procedure, was established for determination of tebuconazole in jujube. After extraction with acetonitrile, the samples were cleaned up by dispersive solid‐phase extraction with primary secondary amine, and determined by high‐performance liquid chromatography tandem mass spectrometry. At fortification levels of 0.01, 0.1 and 2.0 mg kg⁻¹, the average recoveries of tebuconazole in jujube were in the range 97.6–101.9%, with relative standard deviations of 1.5–3.5%. The dissipation and residual levels of tebuconazole in jujube under field conditions were investigated. Tebuconazole dissipated relatively slowly in jujube, with a half‐life of 33.0 days. The terminal residue experiments of tebuconazole in jujube were conducted in four locations in China and the risk was evaluated using risk quotients (RQ ). RQ values were found to be significantly lower than RQ = 1, indicating that the risk to human health of using the recommended doses of tebuconazole in jujube was not significant. This study could provide guidance for the safe and reasonable use of tebuconazole in jujube and serve as a reference for the establishment of limit of maximum residue in China.     

Direct determination of sinigrin in mustard seed without desulfatation by reversed-phase ion-pair liquid chromatography

Reversed-phase ion-pair liquid chromatography has been investigated for directly analyzing sinigrin in mustard seed without desulfatation. After extraction by phosphate buffer (pH 7.0) from the grind-pastes of inactivated-myrosinase mustard seeds, sinigrin was first isolated through deproteinization and centrifugation, followed by filtration and injection into the chromatographic system. A reversed-phase C18 column was used to separate the sinigrin with an eluent of acetonitrile (ACN)-water (20:80) containing 0.02 M tetrabutylammonium (TBA) as the counter ion at pH 7.0. Detection was carried out with an UV detector operated at 227 nm. Factors affecting the chromatographic separation and quantitative determination, such as concentrations of TBA and ACN, and pH, were studied. The linear dynamic range is larger than three orders of magnitude and the detection limit is 0.045 mg/L. The RSD is around 3% and the recovery is 85% (3% RSD, n = 3).     

壳聚糖固定化葡萄糖氧化酶生物传感器测定葡萄糖的含量

应用壳聚糖将葡萄糖氧化酶固定于鸡蛋膜上,结合氧电极制得葡萄糖传感器.实验表明,壳聚糖比戊二醛能更好地固定葡萄糖氧化酶,最佳条件为壳聚糖浓度0.3%、固定化酶量0.8 mg、 pH 7.0、缓冲溶液浓度300 mmol/L和温度25 ℃.本葡萄糖传感器的线性范围为0.016～1.10 mmol/L;检出限为8.0 μmol/L(S/N=3), 响应时间<60 s,有很好的稳定性,寿命>3个月.同一个传感器重复使用以及同方法制作的不同传感器之间都有很好的重现性,RSD分别为2.5%(n=10)和4.7%(n=4).实际样品中可能存在的烟酰胺、 VB6、 VB12、 VE、Ca2+、 Mg2+、 K+和Zn2+等对葡萄糖的测定不产生干扰.本传感器已成功地应用于市售饮料中葡萄糖含量的测定.     

溶剂棒微萃取-HPLC法快速测定常用蔬菜中的痕量尼古丁

建立了一种以溶剂棒微萃取为样品前处理技术,HPLC/UV法测定常用蔬菜中痕量尼古丁的方法。系统优化了溶剂棒微萃取条件以及HPLC法测定尼古丁的相关参数,方法的线性范围0.005~1 mg/L,相关系数为0.9999;检出限0.002 mg/L(S/N=3);在优化的实验条件下对尼古丁的富集倍数可达190倍。样品加标回收率72%~111%(除黄瓜加标样品为47%),相对标准偏差小于10.0%(n=3)。实验证明,本方法可用于常用蔬菜中痕量尼古丁的有效富集、测定。     

Correlation of Quantitative Structure and Inhibition Phytotoxicity for Aromatic Compounds Using Ab Initio Method

1 INTRODUCTION Quantitative structure-activity relationship (QSAR) is one of the necessary methods to evaluate the ha- zards of organic chemicals. QSAR equation could be employed to forecast the biological activity of un- known compounds, which is significant for initial screening and evaluation of toxic compounds[1]. Aro- matic compounds are toxic organic compounds with relatively low water solubility, and their structure- activity relationship has been investigated with AM1 method[2]…