高效液相色谱-串联质谱法测定婴幼儿辅助饼干食品中黄曲霉毒素及其同系物

粉碎的婴幼儿辅助饼干食品样品经体积比为89∶10∶1的乙腈-水-乙酸混合液提取,采用净化剂为50mg十八烷基硅烷、30mg N-丙基乙二胺和30mg氨丙基的QuEChERS方法净化,采用高效液相色谱-串联质谱法测定净化液中黄曲霉毒素B1、黄曲霉毒素B_2、黄曲霉毒素G_1、黄曲霉毒素G_2、O-甲基柄曲霉素、柄曲霉素、黄曲霉毒素M1、黄曲霉毒素M_2等8种黄曲霉毒素及其同系物的含量。以AQ-C_(18)HP色谱柱(2.1mm×100mm,3.0μm)为固定相,以不同体积比的含5mmol·L~(-1)乙酸铵的0.1%(体积分数)甲酸溶液和甲醇的混合液为流动相进行梯度洗脱,串联质谱分析中采用电喷雾离子源正离子扫描模式和多反应监测模式。8种黄曲霉毒素及其同系物的质量浓度在一定范围内与其对应的峰面积呈线性关系,检出限(3S/N)为0.05～0.10μg·kg~(-1),测定下限(10S/N)为0.15～0.30μg·kg~(-1)。以空白样品为基体进行加标回收试验,所得回收率为76.3%～95.9%,测定值的相对标准偏差(n=6)为3.1%～11%。     

高效液相色谱-串联质谱法测定食用槟榔中4种黄曲霉毒素的含量北大核心CSCD

将粉碎后的槟榔样品2.00g用20mL乙腈提取,以100mg N-丙基乙二胺为净化剂分散固相萃取净化萃取液。取上清液以Thermo Accucore aQ C18色谱柱为固定相,以0.005mol·L-1乙酸铵溶液-乙腈混合液为流动相进行梯度洗脱,采用高效液相色谱-串联质谱法测定其中4种黄曲霉毒素的含量。质谱分析中采用电喷雾离子源和多反应监测模式。结果表明:4种黄曲霉毒素的质量浓度均在0.1～10.0μg·L-1内与其峰面积呈线性关系,测定下限(10S/N)为1μg·kg-1。以食用槟榔样品为基质,按标准加入法进行回收试验,回收率为80.0%～99.2%,测定值的相对标准偏差(n=6)为1.5%～9.3%。     

自制混合型固相萃取柱-高效液相色谱法同时测定食品中黄曲霉毒素B1、M1

建立了基于自制混合型固相萃取柱的样品净化/高效液相色谱测定食品中黄曲霉毒素B1、M1的方法。样品经60%乙腈水溶液提取、离心后,通过自制固相萃取柱排除杂质干扰,流出液以Shim-pack VP-ODS C18色谱柱为分离柱,水和乙腈为流动相,用荧光检测器检测,外标法定量。考察了柱类型、柱容量、取样量、提取溶液和流速等对检测的影响,优化了实验条件。在优化条件下,2种毒素在0.40～100μg/L质量浓度范围内与峰面积呈良好的线性关系,相关系数为0.999 4～0.999 7,检出限(S/N=3)为0.050μg/kg。在样品中分别加入0.40、1.0、100μg/L 3种浓度水平的标准品,其加标回收率为53%～112%,相对标准偏差为2.7%～7.1%。该法灵敏度高,操作简单﹑快速,适用于花生、开心果和奶粉等食品中痕量黄曲霉毒素B1和M1的测定。     

在线固相萃取/高效液相色谱-四极杆/静电场轨道阱高分辨质谱检测饲料中的黄曲霉毒素

建立了在线固相萃取/高效液相色谱-四极杆/静电场轨道阱高分辨质谱测定饲料中黄曲霉毒素B1(AFB1)、黄曲霉毒素B2(AFB2)、黄曲霉毒素G1(AFG1)及黄曲霉毒素G2(AFG2)的方法。采用IMMUNOPREPONLINE AFLATOXIN(Part Code:P900)柱为在线固相萃取柱,Diamonsil Plus C18(150 mm×4.6 mm,5μm)柱为分析柱。样品中加入一定量的Na Cl和乙腈-水(80∶20,体积比)溶解,超声提取后,用于后续进样。样品溶液注入在线固相萃取小柱中,通过阀切换技术和HPD共聚焦洗脱模式将保留在SPE柱上的靶标物转移到分析柱中继续进行分离分析,采用外标法定量,采用正离子全扫描模式进行分析。在优化的色谱-质谱条件下,该方法对4种黄曲霉毒素的线性范围为0.5~50.0μg/L,检出限可达0.2μg/kg,定量下限可达0.5μg/kg。在0.5、1.0、5.0μg/kg 3个加标水平下,饲料中4种黄曲霉毒素的回收率为94.6%~114.3%,相对标准偏差不大于8.3%。该方法分析时间短、自动化程度高、检测通量大、检测成本低,可作为饲料中AFB1、AFB2、AFG1、AFG2的快速检测方法。     

超高效液相色谱-串联质谱法快速测定植物油中黄曲霉毒素B1

2.500g植物油样品用10 mL甲醇(7+3)溶液提取,以6 000r·min~(-1)转速离心10min,在-20℃冷冻30min后,上清液经0.22μm有机滤膜过滤,采用超高效液相色谱-串联质谱法快速测定滤液中黄曲霉毒素B_1的含量。以Accucore aQ色谱柱为固定相,以不同体积比的含5mmol·L~(-1)乙酸铵的0.1%(体积分数)甲酸溶液和甲醇的混合液为流动相进行梯度洗脱,串联质谱分析中采用电喷雾正离子源和选择离子监测模式。黄曲霉毒素B_1的质量浓度在0.50～10.00μg·L~(-1)内与其对应的峰面积呈线性关系,检出限(3S/N)为0.02μg·kg~(-1)。以空白样品为基体进行加标回收试验,所得回收率为86.0%～96.6%,回收量的相对标准偏差(n=6)为5.6%～8.4%。     

凝胶渗透色谱-超高效液相色谱-串联质谱法测定奶及奶粉中黄曲霉毒素M_1

建立了用凝胶渗透色谱-超高效液相色谱/串联三重四级杆质谱测定牛奶中黄曲霉毒素M_1的方法。方法以乙腈超声提取,凝胶渗透色谱净化后,以乙腈-0.1%甲酸(3:7,V/V)为流动相,UPLC BEH C18分离,ESI+模式质谱检测,外标法定量。黄曲霉毒素M_1在0.1~4.0μg/L范围内线性关系良好,相关系数r为0.9955,检出限为0.01μg/kg,定量限为0.05μg/kg。牛奶样品在0.1,0.2,0.5μg/kg 3个加标浓度下,黄曲霉毒素M_1的回收率为72.4%~92.2%,相对标准偏差为4.0%~7.8%。     

免疫亲和柱净化-光化学柱后衍生-高效液相色谱法测定柏子仁中的黄曲霉毒素

采用免疫亲和柱净化-光化学柱后衍生-高效液相色谱法测定中药材柏子仁中的黄曲霉毒素G_2、G_1、B_2和B_1。样品经甲醇(7+3)溶液提取,提取液经免疫亲和柱净化,用甲醇洗脱,洗脱液经黄曲霉毒素专用C18色谱柱分离,以甲醇(45+55)溶液为流动相进行洗脱,柱后光化学衍生波长为254nm,荧光检测器的激发波长为365nm,发射波长为440nm。黄曲霉毒素G2、B2的线性范围均为0.125~5.0μg·L~(-1),黄曲霉毒素G_1、B_1的线性范围均为0.50~20μg·L~(-1),检出限(3S/N)在0.012~0.047μg·L~(-1)之间。加标回收率81.4%~105%之间,测定值的相对标准偏差(n=6)在1.6%~6.9%之间。     

液相色谱-串联质谱法测定虾饲料中7种真菌毒素

建立了虾饲料中黄曲霉毒素B_1(AFB_1)、黄曲霉毒素M_1(AFM_1)、T-2毒素(T-2)、HT-2毒素(HT-2)、脱氧雪腐镰刀菌烯醇(DON)、赭曲霉毒素A(OTA)和玉米赤霉烯酮(ZEN)的液相色谱-串联质谱(LC-MS/MS)同时检测方法。样品中加入15 mL乙腈-水(体积比4∶1)和10 mL乙腈饱和正己烷,涡旋混匀,超声提取,MycoSpin~(TM)400多毒素净化柱净化后上机测定。采用Hypersil Gold (150 mm×2.1 mm,5μm)色谱柱进行分离,以甲醇-水(含0.03%氨水)为流动相梯度洗脱,在电喷雾电离模式下正、负离子同时扫描检测,基质匹配外标法定量。在优化条件下,7种真菌毒素的线性相关系数(r~2)均大于0.991,检出限为1.83～12.63μg/kg。在高、中、低3个加标水平下,各目标毒素的回收率为87.5%～116%,相对标准偏差为2.4%～18%。该法可为水产饲料中多种真菌毒素的同时检测提供参考。     

柱前衍生-高效液相色谱法测定茶叶中的黄曲霉毒素B1

应用柱前衍生-高效液相色谱法测定茶叶中黄曲霉毒素B1的含量。样品采用乙腈(85+15)溶液提取,滤液用MycoSepTM226柱净化,加入正己烷和三氟乙酸衍生,经C18色谱柱分离,荧光检测器检测。黄曲霉毒素B1的质量浓度在0.20~10.0μg·L-1范围内与其峰面积呈线性关系,检出限(3S/N)为0.1μg·kg-1。在0.5,1.0,5.0μg·L-1等3个浓度水平进行加标回收试验,回收率在91.9%~102%之间,测定值的相对标准偏差(n=6)在1.5%~6.9%之间。     

超声萃取-反相高效液相色谱-荧光法测定黑参中的苯并芘

0.500 0 g黑参样品用5 mL正己烷于40℃超声提取0.5 h,提取液用分子印迹固相萃取柱净化,净化液以Agilent TC-C_(18)色谱柱为固定相,以88% (体积分数)乙腈溶液为流动相进行分离,采用反相高效液相色谱-荧光法测定。在优化的试验条件下,苯并芘的质量浓度在0.50～20.0μg·L~(-1)内与其峰面积呈线性关系,检出限(3S/N)为0.20μg·kg~(-1)。按标准加入法进行回收试验,回收率为92.8%～97.5%,相对标准偏差(n=6)均小于2.5%。     

Atomic-absorption determination of beryllium in liquid environmental samples

A method is described for the atomic-absorption determination of beryllium in liquid environmental samples after separation by solvent extraction and cation-exchange. The beryllium is first isolated from natural waters and beverages by chloroform extraction of its acetylacetonate from a solution at pH 7 and containing EDTA. The chloroform extract is then mixed in the ratio of 3:6:1 with tetrahydrofuran and methanol containing nitric acid, and passed through a column of Dowex 50 x 8 (H(+)-form). After removal of acetylacetone, chloroform and tetrahydrofuran by washing the resin bed with methanol-HNO(3), beryllium is eluted with 6M hydrochloric acid and determined by atomic-absorption spectroscopy. The method was successfully applied to determine beryllium in tap-, river- and sea-water samples, mineral waters and wines. Beryllium contents in the range from < 0.01 to 2.3 microg/l were found in these materials.     

Simultaneous determination of vanadium and molybdenum as N-benzoyl-N-phenylhydroxamate complexes by combining solvent extraction and liquid chromatography

A normal-phase high-performance liquid chromatographic method for the selective simultaneous determination of vanadium and molybdenum with N-benzoyl-N-phenylhydroxylamine (BPHA) is described. The V(V)-BPHA and Mo(Vl)-BPHA complexes were preconcentrated by solvent extraction into chloroform and injected on to a nitrile-bonded column for chromatography. The mobile phase was a 5.9· 10⁻⁴ M solution of BPHA in chloroform (stabilized with amylene). The detection limits for vanadium and molybdenum were 2.1 and 3.3 ng ml⁻¹, respectively, for an aqueous to organic phase-volume ratio of 20:1. The procedure, applied to the analysis of a synthetic water, showed satisfactory accuracy and precision.     

Ultrasound-assisted analyte extraction for the determination of sulfate and elemental sulfur in zinc sulfide by different liquid chromatography techniques

The speciation and determination of sulfate (SO4(2-)) and elemental sulfur (S degree) in zinc sulfide (ZnS) using ion-chromatography (IC) and reversed-phase liquid chromatography (RPLC) respectively is described. Three sample pretreatment approaches were employed with the aim of determining sulfate: (i) conventional water extraction of the analyte; (ii) solid-liquid aqueous extraction with an ultrasonic probe; and (iii) elimination of the zinc sulfide matrix via ion-exchange dissolution (IED). The separation of sulfate was carried out by an anion-exchange column (IonPac AS17), followed by suppressed conductivity detection. Elemental sulfur was extracted ultrasonically from the acid treated sample solution into chloroform and separated on a reversed phase HPLC column equipped with a diode array detector (DAD) at 264 nm. The achievable solid detection limits for sulfate and sulfur were 35 and 10 microg g(-1) respectively.     

高效液相色谱法测定土壤中香豆素类灭鼠药残留

建立了测定土壤中杀鼠灵、杀鼠醚、溴敌隆、氟鼠灵、溴鼠隆5种香豆素类灭鼠药残留量的柱后衍生荧光检测高效液相色谱方法。样品在加入内标物氯杀鼠灵后用丙酮-氨水-甲醇（体积比为100：3：100）混合液提取,浓缩的提取液用5 mL正己烷-氯仿（体积比为3：1）混合液溶解,NH₂固相萃取小柱净化,用15 mL 50 mmol/L四丁基磷酸二氢铵甲醇溶液洗脱分析物,移除溶剂,用甲醇-0.25%（体积分数）乙酸水溶液（体积比为3：2）混合液溶解,过滤后,经高效液相色谱分离,以甲醇-氨水-水（体积比为1：1：8）混合液为衍生试剂进行柱后衍生,采用荧光检测器检测。杀鼠灵、杀鼠醚、溴敌隆、氟鼠灵、溴鼠隆5种鼠药在0.02～10.00 mg/L范围内线性关系良好,相关系数均大于0.999,定量限（LOQ,S/N=10）为2.2～18.5 μg/L。在0.1～0.3 mg/kg添加水平内,5种灭鼠药的回收率为94.6%～118.0%,相对标准偏差（RSD）为0.8%～10.2% （n=3）。实验结果表明该方法灵敏、准确,重复性好。     

High-performance liquid chromatographic determination of zinc pyrithione in antidandruff preparations based on copper chelate formation

A simple and rapid method for the determination of zinc pyrithione (ZPT) in antidandruff preparations by high-performance liquid chromatography (HPLC) has been developed. ZPT in samples was converted into a stable copper(II) complex by mixing with cupric sulphate solution followed by extraction with chloroform. HPLC was carried out on a Nucleosil 5 C18 column (15 cm X 4.6 mm I.D.) using methanol-water (3:2) as the mobile phase with UV detection at 320 nm. The calibration graph was linear from 0.1-0.5 micrograms for ZPT. The recoveries from four shampoos were 98.0-100.6% with high accuracy.     

峰蜜中杀虫脒的快速测定法

 建立了测定峰蜜中杀虫脒的薄层色谱法,不需要大型仪器和特殊试剂,不受基体干扰,整个测定过程仅需３ｈ,回收率在７０％以上,能满足蜂蜜生产和加工现场检验工作需要。     

大口径毛细管气相色谱法测定罂粟壳中的生物碱

摘要：采用超声提取大口径毛细管气相色谱法同时测定罂粟壳中可待因、吗啡、蒂巴因、罂粟碱和那可汀的质量比,用HP-1（5m×0.53mm×2.65μm）毛细管柱,GC-FID测定,结果表明,可待因、吗啡、蒂巴因、罂粟碱和那可汀的平均回收率分别为94.0％,96.5％,93.8％,91.0％,91.4％,RSD=0.92％～2.75％。     

配位色谱法从葛根素浸膏中分离纯化葛根素

建立了采用配位色谱柱从葛根素浸膏中分离纯化葛根素的方法。以铜离子为中心离子,制备了中心离子含量为7%的配位色谱柱。样品上样于配位色谱柱后,以氯仿-甲醇（体积比为10∶1）混合溶剂洗脱,得到了较纯的葛根素,较之用传统的硅胶色谱柱纯化,纯度提高了11%,回收率提高了12%,且柱容量提高了两倍。配位色谱改变了葛根素在传统硅胶柱上的洗脱顺序,对目标物质的分辨率比传统硅胶色谱柱高。     

COMPATIBILITY IN POLYMER BLENDS OF POLY (VINYL ACETATE) AND POLY (METHYL METHACRYLATE)STUDIED BY NMR

Compatibility of poly (vinyl acetate) (PVAc) with poly (methyl methacrylate) (PMMA) mixtures has been studied by using nuclear magnetic relaxation, differential scanning calorimeter and small-angle X-ray scattering techniques. The nuclear magnetic relaxation time T_1's were measured as a function of composition in blends of PMMA and PVAc prepared from chloroform solution. The results show that the system is miscible for casting from chloroform solution.     

Determination of paraquat in marijuana by reversed-phase paired-ion high performance liquid chromatography.

A sensitive and selective method is described for the quantitative determination of paraquat in marijuana. Paraquat is extracted from finely ground plant material with hydrochloric acid with sonification, and the resulting acidic solution is extracted with chloroform:isopropanol (9:1) and evaporated to dryness. The residue is reconstituted with aqueous phosphate buffer pH 7.0; the solution is passed through a C-18 SEP-PAK TM and is analyzed with high performance liquid chromatography, using a reversed-phase column and an "ion pairing" reagent in the mobile phase. The recovery of paraquat in laboratory-spiked material varied from 90-97%. Results obtained with confiscated, field-sprayed marijuana by the procedure described were in excellent agreement with those obtained with a well-established ultraviolet procedure. The calculated limit of detection with this method is 2 ng of paraquat.