负载茜素红S的纳米磁性碳粉修饰电极测定牛白蛋白

采用化学沉积法在纳米碳粉上合成磁性Fe3O4颗粒,纳米碳粉吸附茜素红S后通过磁力附着在石墨电极上,制成了负载茜素红S的纳米磁性碳粉修饰电极。研究了该电极在0.014 mol/L H2SO4-0.2 mol/L KC l溶液中对ARS-牛白蛋白的电还原作用,考察了多种实验条件对峰电流的影响。在-0.45 V电位下,牛白蛋白浓度在1.5×10-8~9×10-7mol/L范围内与线性扫描伏安法还原电流成反比,从而实现对牛白蛋白的测定,并初步研究了电化学反应机理。此方法制成的磁性纳米颗粒修饰电极集分离、富集、测定和更新于一体,具有更新方便的特点。     

铅笔芯电极表面多层自组装膜制备及其对牛血清白蛋白的测定

采用电沉积技术将金沉积在铅笔芯电极(PGE)上,借助Au-S作用,将L-半胱氨酸(L-Cys)组装于金表面,利用吖啶橙(AO)与L-半胱氨酸之间的静电作用,将吖啶橙间接组装于金表面,构建成三层自组装膜电极AO/L-Cys/Au/PGE。将该复合膜电极连接在电化学工作站的工作电极和辅助电极端之间,与参比电极浸入溶液中,构建了一个新的检测回路。采用电化学阻抗谱技术和循环伏安法对多层自组装膜的组装过程进行表征。利用吖啶橙与牛血清白蛋白(BSA)间的相互作用,采用零流电位法,通过对比加入不同浓度BSA后零流电位值的变化(ΔEzcp)对BSA进行检测。结果显示,在1.0×10-9～1.0×10-5mol/L范围内,ΔEzcp与BSA浓度的对数值呈良好线性,相关系数(r)为0.997 0,检出限为1.41×10-11mol/L。该方法选择性和重复性好,有望应用于其它蛋白的测定。     

树脂快速静态分离-石墨炉原子吸收光谱法测定砷的形态化合物

用离子交换树脂静态吸附和溶剂萃取相结合的分离技术,结合塞曼GFAAS测定方法,分析了砷的四种形态化合物:As(Ⅲ)、As(Ⅴ)、MMA和DMA。文中的静态吸附分离是指采用少量树脂,对小体积溶液室温下用电磁搅拌数分钟,经短时间的相对静态的吸附或解吸过程,达到分离的目的。分离和测定全过程约为30～40min。方法对As(Ⅲ)、As(Ⅴ)、MMA和DMA和总As的检出限分别是0.94、0.89、0.94、0.26(富集4倍)和0.90μg/L。可应用于河水、植物中砷形态分析。     

柱前衍生高效液相色谱法检测合成牛磺酸及其中间产物的含量

提出了柱前衍生高效液相色谱法检测工业合成牛磺酸及其中间产物2-氨基乙基硫酸酯.用2,4-二硝基氟苯作为衍生化试剂,以乙腈-水-磷酸缓冲溶液(pH=7)为流动相,在360nm处进行紫外检测.上述两种物质在C_(18)反相色谱柱上得到良好的分离,并进行了定量测定.     

巯基棉分离富集-石墨炉原子吸收法测定痕量铟的研究

研究了巯基棉(SCF)富集痕量In(Ⅲ)的条件,并用石墨炉原子吸收光谱(GFAAS)法测定痕量In(Ⅲ)。结果表明,在pH=4.0时,巯基棉能定量富集痕量In(Ⅲ),其饱和吸附量为181μg/g。吸附的In(Ⅲ)可被0.8 mol/L的HNO3定量洗脱。本法用于人工合成铝基、锌基样品和锌精矿中痕量In(Ⅲ)的富集和测定,回收率为92.8%~100.6%。     

Separation and Concentration of the Trimethylselenonium Ion for Its Determination in Urine by Graphite Furnace Atomic Absorption Spectrometry

The separation and concentration methods for the trimethylselenonium ion (TMSe) in urine samples were developed utilizing the formation of the ion pair of TMSe with tetrakis(4-fluorophenyl)borate. The ion pair could be quantitatively collected by a solvent extraction technique as well as a cellulose nitrate (CN) filter collection technique. The collected TMSe was determined by graphite furnace atomic absorption spectrometry with the addition of palladium as a matrix modifier. In the case of urine analysis for TMSe, the CN filter technique gave better reproducibility than the solvent extraction technique. The detection limit of this method for TMSe was 1 ngSe/ml for 20 ml of urine sample.     

离子交换分离石墨炉原子吸收光谱法测定高纯铟中痕量铜

高纯铟样品经盐酸溶解、以阳离子交换树脂分离出痕量铜后,用石墨炉原子吸收光谱法测定铜。研究了溶样方法、离子交换分离和测定铜的条件:用8mL浓盐酸将1g样品溶解;以0.6mol/L盐酸作为淋洗液进行离子交换,可把绝大部分铟基体及样品中痕量的银、砷、镉、硅分离除去,随后用2.0mol/L盐酸把铜洗出并收集之。铝、铁、镁、镍、铅、锡、铊、锌与小于10μg的铟不能与铜分离,但对测定无影响。当称样量为1g,进样量为50μL时,方法线性范围为1~4ng/mL,检出限为0.1ng/mL,测定下限为0.001μg/g,比行业标准方法 YS/T 230.1—2011的0.1μg/g低两个数量级。方法用于实际样品分析,结果与电感耦合等离子体质谱法(ICP-MS)相符,相对标准偏差(RSD,n=8)为1.7%~18.5%,加标回收率为94.8%~115.0%。     

HPLC Determination of Glyphosate,Aminomethylphosphonic Acid,and Glufosinate Using a Hypercarb Porous Graphite Adsorbent

A method for the HPLC determination of glyphosate, aminomethylphosphonic acid, and glufosinate using the gradient separation of analytes on a Hypercarb porous graphitized carbon adsorbent and an aqueous solution of ammonium formate and ammonia as a mobile phase is proposed. Analytes are detected using quadrupole and three-quadrupole mass spectrometers. In order to increase the retention of the analytes, the chromatographic column is washed with water before the injection of a sample solution. This procedure results in a three- to fourfold increase in the retention factors of the analytes in comparison with the analogues described in the publications.     

Simultaneous Determination of Heavy Metals in Bovine Liver and Oyster Tissue by Solvent Extraction-Reversed Phase High Performance Liquid Chromatography

Abstract

High performance liquid chromatographie method for the simultaneous determination of ppm levels of cadmium, nickel, lead, zinc, cobalt, copper and bismuth in biological samples has been developed. Each 250 mg of Bovine Liver(NBS 1577) or Oyster Tissue(NBS 1566) was ashed in a muffle furnace over night at 500 to 55O°C. Then the ash was treated with 1.5 ml of 2 N hydrochloric acid; and the solution was put into a separatory funnel. The dissolved heavy metals were extracted into chloroform as hexamethylenedithiocarbamato chelates. The metal chelates were separated on a reversed phase column(5 μm, ODS, 4.6 × 15O mm), and determined by measuring the peak height of each metal chelate. Cd, Ni, Pb, Zn and Cu were determined accurately over the concentration range of 0.5–850 ppm with standard deviation ca. 7%.     

高频燃烧–红外吸收法测定石墨及其制品中的硫含量

建立高频燃烧–红外吸收法测定石墨及其制品中的硫含量。结合高频红外碳硫分析仪器特点,试验确定了方法的实验条件:试样粉碎至2.5 mm以下颗粒状,所有试样均为干燥状态,称样量控制在0.200 0~0.300 0 g之间,助熔剂为纯铁和钨粒,助熔剂添加顺序为纯铁+样品+钨粒。采用该方法对石墨标准样品进行测定,测定结果与标准值相符合,测定结果的相对标准偏差为0.86%~1.96%(n=10)。该法可用于石墨及其制品中硫含量的测定。     

石墨炉原子吸收分光光度法测定血清中铜

铜系人体内含有的微量元素。测定血清中Cu/Zn比值,有助于病因分析和提供诊断依据。目前,测定血清铜所用的仪器分析方法甚多。本法无需对血清样进行预处理,取样量仅20—50μl。碱金属和碱土金属卤化物无干扰。特征质量m。为5.6pg/0.0044A.S,回收率98～102%,变异系数1.7-2.7%。     

喜树碱合成中间体的光学异构体分离及分离机理研究

首次在CHI-DMB及(R,R)-DNB-DPEDA手性柱上对喜树碱合成中间体--2-[N-对甲苯磺酰基-(R)-脯氨酰氧基]-2-[6-氰基-(1,1-亚乙二氧基)-5-酮-1,2,3,9-四氢中氮茚-7-基]-丁酸乙酯进行了光学异构体分离. 考察了流动相中极性醇类添加剂对手性分离种类及浓度对分离的影响, 并比较了溶质在这两种手性柱上的手性识别机理, 结果发现在这两种手性固定相上, 溶质与手性固定相之间的吸引作用都是产生手性识别的关键. 从溶质与固定相的空间结构看, 在CHI-DMB手性柱上, π-π堆积作用及偶极偶极作用起了关键作用; 而在(R,R)-DNB-DPEDA手性柱上, π-π堆积作用, 偶极偶极作用及氢键作用对分离起了重要作用. 此外, 空间位阻在喜树碱中间体的光学异构体分离中也起了一定的作用. 根据溶质和固定相的空间结构, 推导出的两个光学异构体的流出顺序, 并通过相应的光学异构体得到验证.     

石墨炉原子吸收光谱法测定尿镉

采用磷酸作为基体改进剂，石墨炉原子吸收光谱法测定了尿镉，其检测限为０．０７μｇ／Ｌ，标准曲线线性范围０．０－５．０μｇ／Ｌ回收率９９．９１％，方法准确、简便、快速、污染少。     

用于毛细管电泳DNA分离的合成聚合物*

毛细管电泳的无胶筛分方法在DNA片段分离、DNA 测序方面取得了显著的成绩并已成功应用于人类基因组计划.该法是在毛细管柱中充入一定浓度和组成的线性高分子溶液,利用其对样品组分电泳迁移时的阻滞作用,按分子量大小对DNA等生物大分子进行筛分分离分析.因此,聚合物筛分介质的类型、组成和性质会显著影响分离效果.近年来,由于受到基因组计划的影响,出现了许多用于DNA片段分离和DNA测序的水溶性高分子聚合物,并取得很大进展.本文按照均聚物和共聚物的分类,综述了作为筛分介质的各种合成聚合物及其应用效果,并简要介绍了有关的筛分理论和分离的评价指标.     

Multiresidue Determination of Ten Nonsteroidal Anti-inflammatory Drugs in Bovine,Porcine, and Chicken Liver Tissues by HPLC-MS/MS

Nonsteroidal anti-inflammatory drugs (NSAIDs) are the group of drugs having the therapeutic efficacy of analgesic and antipyretic. To detect health-threatening residues of NSAIDs, a fast and easy multiresidue method based on liquid chromatography tandem mass spectrometry (LC-MS/MS) was described. Ten NSAIDs were extracted from the tissues using 2 mL of acetonitrile and 0.1 mL of 2 mM ammonium formate in distilled water. After clean-up using C18 sorbent, it was evaporated under nitrogen, reconstituted with 1 mL distilled water and analyzed by LC-MS/MS. The method was validated based on guideline for residue testing laboratory. Furthermore, the method has also been applied successfully to detect ten NSAIDs from bovine, porcine, and chicken liver tissues. In a total of 315 liver samples tested, acetylic salicylic acid was detected from 28 porcine and 2 chicken liver tissues at levels of 13?～?576 and 50?～?53 ng/g, respectively. Subsequently, paracetamol was detected in 15 porcine liver tissues with a detection levels of 28?～?381 ng/g. Phenylbutazone and its metabolite, oxyphenylbutazone, were detected at 247 and 15 ng/g range in one of the bovine liver tissue, respectively.     

Nafion化学修饰圆盘预富集-石墨炉 原子吸收联用法对牛血超氧化物歧化酶中铜、锌分布状态的研究

本文研究了Nafion化学修饰钨丝圆盘预富集-石墨炉原子吸收(GFAAS)方法测定牛血超氧化物歧化酶(SOD)中游离态Cu～(2+)及Zn～(2+)的方法,并用GFAAS法直接测定SOD中铜、锌的总量,证实了牛血SOD中金属辅基铜、锌原子个数比为1:1,初步探讨了一定浓度的牛血SOD中Cu～(2+)、Zn～(2+)的表观离解平衡常数。为提高SOD的活性和稳定性的研究,提供了一种有效的方法。     

涂钨石墨管石墨炉原子吸收光谱法测定人参中锗

石墨炉原子吸收法测定锗的问题主要是样品原子化前会形成易挥发的GeO,影响分析灵敏度。有关测锗的报道见文献。本工作应用CCl_4萃取和水反萃取,涂钨石墨管石墨炉原子吸收测定人参中锗,获得满意的结果。     

石墨消解石墨炉原子吸收光谱法测定地沟油中的镍、铅

建立石墨炉原子吸收光谱仪测定地沟油中镍和铅含量的方法。采用石墨消解仪对样品进行消解,消解试剂为10 m L硝酸和2 m L高氯酸。对灰化温度、原子化温度等实验条件进行了优化,用磷酸二氢铵作基体改进剂消除氯离子的干扰。镍、铅的线性范围分别为0~50μg/L,0~100μg/L,相关系数均大于0.999。镍、铅的检出限分别为0.03,0.10 mg/kg。镍、铅测定结果的相对标准偏差分别为2.8%,2.5%(n=6)。镍、铅的回收率分别为94.0%,95.0%。该方法适用于测定地沟油中镍和铅元素含量。