2-(2-喹啉偶氮)-1,3-二羟基苯固相萃取分光光度法测定环境样品中钒的研究

根据新试剂 2 (2 喹啉偶氮 ) 1,3 二羟基苯 (QADHB)与钒的显色反应及C1 8固相萃取小柱对显色络合物的固相萃取 ,建立了一种测定环境样品中痕量钒的新方法 ,在pH 3 5的柠檬酸 -氢氧化钠缓冲介质中 ,溴化十六烷基三甲基铵 (CTMAB)存在下 ,QADHB与钒反应生成 2∶1稳定络合物 ,该络合物可用C1 8固相萃取小柱富集 ,小柱上富集的络合物用乙醇 (内含 2 %乙酸 )洗脱后用分光光度法测定 ,在富集后的测定液中 ,络合物最大吸收波长为 5 5 2nm ,摩尔吸光系数ε=8 2 9ⅹ 10 4 L·moL- 1 ·cm- 1 ,钒含量在 0～ 1 0 μg ml内符合比尔定律。方法用于几种环境样品中钒的分析 ,结果令人满意     

固相萃取-液相色谱-串联质谱法测定氯化消毒副产物二氯对苯醌

目的 建立饮水中新型氯化消毒副产物二氯对苯醌的固相萃取-液相色谱-串联质谱检测方法。方法 水样经0.45 μm滤膜过滤,用 Oasis HLB 固相萃取小柱富集进样,以含0.25%甲酸甲醇溶液-0.25%甲酸的水溶液为流动相,梯度洗脱,经Agilent ZORBAX Eclipse XDB-C18色谱柱（2.1 mm×50 mm,1.8 μm） 分离后,采用四极杆串联质谱仪电喷雾负离子模式和多反应监测（MRM）模式进行检测。结果 二氯对苯醌在2～100 μg/L的范围内回归方程为Y = 12.978x + 0.285,线性相关系数r = 0.9937;方法检出限为0.01 μg/L,定量下线限为0.03 μg/L。管网末梢自来水加标回收率为80.0％～85.0％,相对标准偏差(RSD)为3.4%～4.1%。结论 方法的灵敏度和准确度较高,适用于饮用水中二氯对苯醌的测定。     

同位素稀释-气相色谱串联质谱法测定啤酒中4种亚硝胺类化合物

目的 建立啤酒中4种N-亚硝胺类化合物（N-亚硝基二甲胺、N-亚硝基二乙胺、N-亚硝基二丙胺、N-亚硝基二苯胺）的同位素稀释固相萃取-气相色谱串联质谱测定方法。 方法 样品经活性炭固相萃取小柱富集、二氯甲烷洗脱,洗脱液经氮吹浓缩定容后,采用INNOWAX毛细管色谱柱分离,多反应监测（MRM）模式检测,同位素稀释内标法定量。 结果 各物质在5 μg/L~200 μg/L范围内线性关系良好,相关系数均大于0.9995。方法的检出限为0.03-0.10 μg/L,定量限为0.10~0.33 μg/L。不同水平的加标回收率为72.1%~100.3%,相对标准偏差为1.5%~9.5%（n=6）。 结论 该方法操作简单,灵敏度和准确度高,适用于啤酒中4种N-亚硝胺类化合物的测定。     

微波消化—固相萃取光度法测定中草药及制剂中的镍

目的:选用2-(2′-喹啉偶氮)-5-二乙氨基苯胺(QADEAA)作为显色试剂,并研究了其与镍的显色反应。方法:在pH=6.0的六次甲基四胺—盐酸缓冲溶液介质中,SDS存在下,2-(2′-喹啉偶氮)-5-二乙氨基苯胺(QADEAA)与镍反应生成2∶1稳定配合物,该配合物可被Waters Porapak Sep-Pak-C18固相萃取小柱萃取,用异丙醇洗脱后用光度法测定。结果:异丙醇相中配合物λmax=595 nm,ε=1.38×105 L/mol/cm。镍含量在0~1.0μg/ml内符合比尔定律。结论:以上方法可用于中草药及制剂中镍元素含量的测定。     

饮用水中3种一氯酚异构体的液相色谱-质谱联用法测定研究

目的:建立一种能同时测定饮用水中2-氯酚、3-氯酚和4-氯酚的检测方法。方法:水样经Oasis(HLB固相萃取小柱富集、净化后,在C8柱(250 mm×4.0 mm×5μm)上,以乙酸-乙酸铵缓冲溶液(5 mmol/L,pH=4.5)/乙腈/甲醇(65:28:7)为流动相,采用大气压化学电离(APC I)离子化方式在选择离子监测(SIM)模式下进行检测,定量检测离子为m/:z 127[M-H]-。结果:2-氯酚、3-氯酚和4-氯酚的日内与日间精密度分别小于9.3%和10.9%,它们在0.05~5.00μg/L范围均具有良好的线性,水样中它们的最低定量检出限分别为0.05、0.02和0.02μg/L。结论:本方法可用于饮用水中痕量一氯酚的测定。     

自动固相萃取-气相色谱-质谱法测定生活饮用水中60种半挥发性有机物

目的提出一种同时测定生活饮用水中60种半挥发性有机物的自动固相萃取-气相色谱-质谱联用法。方法1 L水样中加入5 m L甲醇,通过自动固相萃取装置使用LC-Florisil固相萃取柱对水样进行富集,再分别用5 m L二氯甲烷和5 m L乙酸乙酯洗脱,氮吹浓缩定容至1 m L,进样分析。结果60种半挥发性有机物在(0.125~4.00)μg/L的含量范围内具有较好的线性,其相关系数均≥0.99,方法检出限为(0.002~0.06)μg/L,检测限为(0.01~0.26)μg/L,回收率范围70.8%~129%,精密度(RSD)范围0.2%~21.5%。结论该方法实现了前处理过程自动化,具有准确度高、操作简单和溶剂使用量少等优点,适用于同时测定生活饮用水中60种半挥发性有机物。     

高铁试剂离子对固相萃取光度法测定几种中草药中的铁

根据高铁试剂与铁的显色反应以及用Waters PorapakRSep—Pak—C18固相萃取小柱对显色配合物的高倍数富集,建立了一种测定中草药中铁的新方法。在pH=4.0的HAc—NH4Ac缓冲介质中,CTMAB作为离子对试剂,高铁试剂与铁反应生成3∶1稳定配合物,该显色配合物可用C18固相萃取小柱进行富集,用乙醇(内含1%的乙酸)洗脱后用光度法测定,在乙醇相中配合物λmax=610 nm,ε=8.92×103L/(mol.cm)。铁含量在0.05~5.0μg/ml内符合比尔定律,方法用于中草药中铁含量的测定,结果令人满意。     

SPE小柱在调味品3-氯-1,2-丙二醇检测中的应用研究

目的:了解固相萃取小柱在调味品3-氯-1,2-丙二醇测定中的应用效果。方法:采用固相萃取小柱替代传统的基质固相分散萃取技术对样品进行前处理,用正己烷净化,乙醚洗脱,结合三乙胺催化的七氟丁酸酐(HFBA-Et3N)衍生,GC-MS测定。结果:实验结果表明,SPE小柱对样品的净化效果较好,与国标法比较测定结果基本一致,t检验无显著性差异(P>0.05),对5种调味品的三个加标水平回收率在91.6%～108.2%之间,相对标准偏差在3.05%～8.79%之间(n=6)。结论:该方法简单、快速、准确、经济,适用于调味品中3-MCPD的检测。     

固相萃取-分光光度法测定食品和水中亚硝酸盐

目的 建立腌渍蔬菜、肉制品、食盐和水中亚硝酸盐的快速固相萃取净化-分光光度法。方法 1 g粉碎样品加入饱和硼砂溶液,沸水浴15 min提取其中的亚硝酸盐。提取液经0.22 μm有机系滤膜过滤和PRiME HLB固相萃取小柱净化除去其中蛋白质、脂类等杂质后,取过柱液进行重氮偶氮显色反应,于538 nm处进行分光光度测定。水样过膜过柱后直接用于分光光度测定。结果 方法线性范围为0.0080～0.500 μg/ml,以10次空白测定值的3倍相对标准差计算方法检出限,当水样取8 ml时,检出限为0.0032 mg/L;当固体样品称取1g样品时,检出限为0.13 mg/kg。相对标准偏差为0.38%～4.67%,腌菜、肉制品、食盐、水样的加标回收率分别为93.3%～98.4%、88.5%～102%、97.2%～103%和95.6%～98.6%。与国家标准方法比较,测定相对偏差为1.01%～5.31%。结论 该方法简单、快速、准确,适用于腌制蔬菜、肉制品、水和食盐样品中亚硝酸盐快速检测。     

高效液相色谱-电喷雾电离质谱联用法测定水中痕量五氯酚研究

目的建立简便、灵敏、准确的测定水中痕量五氯酚的固相萃取-高效液相色谱-质谱联用的检测方法,并用于生活饮用水、渔塘水中痕量五氯酚的污染监测。方法水样经Oasis HLB小柱富集,以甲醇-甲基叔丁基醚(10+90)洗脱,采用甲醇和2mmol/L醋酸铵溶液为流动相进行梯度淋洗,以ZORBAXEclipseXDB-C18柱( 150mm×2 1mm×5μm)分离,通过选择性离子检测(SIM)及电喷雾电离离子化技术进行测定。结果线性范围为5 0μg/L~500 0μg/L,定量检测下限为5 0ng/L,方法回收率在82 8% ~108 5%,RSD均小于10%。结论该法灵敏度高、操作简便、快速,适用于实际样品的测定。     

Synthesis, structure and biological activity of copper(II) complexes of 4-(2-pyridylmethyl)-1,7-dimethyl-1,4,7-triazonane-2,6-dione and 4-(2-pyridylethyl)-1,7-dimethyl-1,4,7-triazonane-2,6-dione

Four mononuclear copper(II) complexes 1-4 have been synthesized with two new N-functionalized macrocyclic ligands L(1) and L(2). All complexes are well characterized by various spectroscopic techniques, elemental analyses and conductivity measurements. Results suggest that Cu(II) ion has N(2)O coordination from ligand and S(2) from two coordinated solvent molecules (SCH(3)CN for 1 and 3 while CH(3)OH for 2 and 4). The crystal structure of a representative complex 3 strengthen the proposed formulations for other isostructural copper(II) complexes. The structure of 3 shows few interesting features including rare bent mode of the coordinated CH(3)CN molecules. All complexes were assayed for in vitro antimicrobial activity against clinically isolated resistant strains of Pseudomonas aeruginosa and Proteus vulgaris; and standard strains of Staphylococcus aureus, P. aeruginosa, Klebsiella planticola and Escherichia coli. Results indicate that the copper complexes possess notable antimicrobial properties with MIC values of 62.5-500 microg/ml. Studies on the U87 cancerous cell lines show potent cytotoxicity with IC(50) and IC(90) values of 2.9-93.5 and 30-250 microg/ml, respectively. In vitro toxicity tests demonstrate that all copper complexes are less cytotoxic than that of gentamycin on normal HEK cell lines. These copper complexes show the potential to act as antimicrobial and anticancer agent.     

催化动力学光度法测定水中痕量铬(Ⅵ)

目的:建立了催化动力学光度法测定水样中痕量Cr(Ⅵ)的新方法。方法:在硫酸介质中,痕量Cr(Ⅵ)催化过硫酸铵氧化邻甲氧基酚显色,其化合物的最大吸收波长为513nm。结果:方法的线性范围为01016～116μg/25ml Cr(Ⅵ),检出限为5142×10-10g/ml Cr(Ⅵ),相对标准偏差(RSD)<3.27%,样品加标回收率为9716%～10111%。结论:该法用于环境水样中微量铬含量的测定快速、准确、简便。     

固相萃取-高效液相色谱法测定水中痕量苯并（α）芘

目的建立水中痕量苯并（a）芘的检测方法。方法采用高效液相色谱法，以Waters PAH C18（250mm×4．6mm×5μm）为分析柱，甲醇为流动相，流速1．2ml／min，荧光检测器检测，水样用ENVI-18柱富集并用四氢呋喃洗脱。结果方法最低检出限为0．002μg／L，线性相关系数r=0．9999，平均回收率为86．4％，RSD=2．33％（n=6）。结论本方法可以对水中苯并（a）芘进行定量测定，且简便、准确、可靠。     

Synthesis and characterization of dinuclear macrocyclic cobalt(II), copper(II) and zinc(II) complexes derived from 2,2,2('),2(')-S,S[bis(bis-N,N-2-thiobenzimidazolyloxalato-1,2-ethane)]: DNA binding and cleavage studies

New homodinuclear macrocyclic complexes of cobalt(II), copper(II) and zinc(II) were isolated from the newly synthesized ligand 2,2,2',2'-S,S[bis(bis-N,N-2-thiobenzimidazolyloxalato-1,2-ethane)]. The structures of the complexes were elucidated by elemental analysis, molar conductance measurements, IR, 1H NMR, 13C NMR, electronic and ESI-MS spectroscopic techniques. In complex 1, Co(II) ions possess a tetrahedral coordination environment composed of O2S2 donor atoms while its Cu(II) and Zn(II) counterparts 2 and 3, respectively, reveal a six coordinate octahedral structure, defined by the O2S2 donors from the macrocyclic ring and two chloride ions. Molar conductance and spectroscopic data also support the proposed geometry of the complexes. DNA binding properties of complexes 1-3 were investigated using electronic absorption spectroscopy, fluorescence spectroscopy, viscosity measurements and cyclic voltammetry. The absorption spectra of complexes 2 and 3 with calf thymus DNA showed hypochromism, while complex 1 showed hyperchromism attributed to a partial intercalation and electrostatic binding modes, respectively. The intrinsic binding constant K(b) of complexes 1-3 were determined as 16.6 x 10(4) M(-1), 4.25 x 10(4) M(-1) and 3.0 x 10(4) M(-1), respectively. The decrease in the relative specific viscosity of calf thymus DNA with increasing concentration of the complexes authenticates the partial intercalation binding mode. Gel electrophoresis of complex 2 with plasmid DNA demonstrated that complex exhibits excellent "artificial" nuclease activity.     

柱前衍生-高效液相色谱法测定L-(-)-岩藻糖含量

目的采用对氨基苯甲酸乙酯(p-ABBE)为衍生剂,建立L-(-)-岩藻糖含量测定的柱前衍生-高效液相色谱法。方法对L-(-)-岩藻糖样品与p-ABBE的衍生比例、衍生温度、衍生时间等衍生条件进行优化,同时进行色谱柱、流动相等高效液相色谱条件的优化。结果衍生化条件为:衍生化试剂(p-ABEE)和L-(-)-岩藻糖的摩尔比为7∶1,衍生温度为85℃,反应时间为1.5 h;色谱条件为:色谱柱Agilent 5 TC-C18(2)(250 mm×4.6 mm,5μm),流动相为0.02%TFA-乙腈(77∶23,V/V),流速为1.0 ml/min,检测波长为307 nm。本方法在0.50 mmol/L^6.02 mmol/L浓度与峰面积呈现良好的线性关系(r=0.9995),定量限(S/N=10)及检出限(S/N=3)分别为0.20 ng/ml和0.10 ng/ml;平均加标回收率为82.94%,RSD为1.74%。结论本方法操作简便、结果准确、实用性强,能够用于L-(-)-岩藻糖的含量测定。     

Determination of benzoic acid in air

A gas chromatographic method is described for direct determination of free benzoic acid in air samples. Benzoic acid is absorbed from air on Porapak Q packing in the presence of other compounds, thermally desorbed at 240 degrees C with helium flow into a capillary column, and detected with a flame ionization detector. The method is calibrated by injecting benzoic acid standard solutions into the Porapak Q. The method was validated with dynamic standards and recovery yields were good. Benzoic acid levels of 0.1-1.0 ppm (v/v) in air can be determined with sampling volumes of 8-24 L.     

A method for the trace analysis of naptalam (N-1-naphthylphthalamic acid) in water

A method for the trace analysis of naptalam, N-1-naphthylphthalamic acid, in water is presented. Naptalam, a pre-emergent, broad-leaf, and grassy herbicide, is used with soybean, peanut, and vine crops. Tap and well water samples are extracted on a cyclohexyl solid phase extraction cartridge, eluted from the cartridge with methanol, and evaporated to dryness. The sample is esterified with diazoethane, evaporated to dryness, reconstituted with methanol, and converted to the stable N-1-naphthyl phthalimide in the gas chromatograph (GC) injector port for detection and quantitation using a nitrogen-phosphorus detector. Sample injection technique and injector port temperature are critical to high derivatization yields. Confirmation of conversion to N-1-naphthyl phthalimide was made by gas chromatograph/mass spectrometer (GC/MS). Spiking tests at levels of 3 to 100 g/L showed good recovery.