加速器质谱法测定环境和生物样品中的129I

建立了环境和生物样品中的129I的分析方法,采用碱式灰化、萃取-反萃、沉淀等步骤对环境和生物样品中的碘进行预浓集,用131I[NaI] 为放射性示踪剂优化各分步的制备条件,运用加速器质谱法测定了北京地区松针和干草、青岛地区海藻和海水中的129I/127I.用超热中子活化法测定样品中的稳定碘(即127I)含量.上述松针、干草、海藻和海水样品中的129I/127I分别为8.11×10-9、5.97×10-9、1.70×10-10和6.05×10-10;相应的129I浓度分别为3.22×10-15、1.24×10-14、1.27×10-14 g/g干重和2.30×10-14 g/L.与文献报道值相比,我国与国外同类地区相当甚至更低,比法国和英国乏核燃料后处理厂附近环境中的129I低2～3个数量级,表明我国这些非核设施影响地区的129I处于当今全球环境的本底放射性沉降水平.     

高纯钨酸钠中痕量杂质元素的共沉淀分离和ICP—AES测定

提出了以氢氧化镧为共沉淀剂，对高纯钨酸钠中痕量金属杂质元素（钙，镉，钴，铜，铁，锰，镍，锌）进行了共沉淀分离富集后以ＩＣＰ－ＡＥＳ法进行测定的方法，ｐＨ１２时，用１０ｇ．Ｌ＾－１镧溶液６ｍｌ进行两次共沉淀，能使杂质元素定量分离回收，钨酸钠残留量降至很低水平，试样测定结果表明，各元素回收率在９２．４％～１０４．８％之间，相对标准偏差为１．８％～６．９％。     

磷酸铈共沉淀分离富集硫酸钴中痕量铅及铅的原子吸收光谱测定

提出了用磷酸铈(CePO4)作为共沉淀捕集剂分离富集CoSO4溶液中的痕量Pb2+,用火焰原子吸收光谱(FAAS)测定的方法。共沉淀效率受pH、Ce(NO3)3和H3PO4溶液用量的影响。结果显示,在溶液pH3.0～4.0时,CePO4能够定量共沉淀CoSO4溶液中的Pb2+,对于20mL的样品溶液,方法的检出限为5.59×10-2mg/L,铅的标准加入回收率为98.32%,排除了基体干扰,取得了较为满意的结果。     

加速器质谱用NH4HfF5的分离条件及热稳定性研究

研究了不同淋洗液浓度对加速器质谱测量用NH4HfF5制样过程中阳离子交换产额的影响,用重量法对阳离子交换产额进行了测量。研究了多相法合成的NH4HfF5样品热稳定性,用XRD表征了不同温度处理下样品物相的变化情况。研究了三种(液相、固相和多相)合成方法对样品中180HfF5-离子束流和19F-/16O-比值的影响,用离子源进行了测量。结果表明:在阳离子交换过程选择60mL 1mol/L HCl为淋洗液时,阳离子交换产额可达97%。多相法合成的NH4HfF5样品在573K热处理1h后物相转变为NH4Hf2F9,在773 K、973 K、1173 K和1373 K热处理1h后物相则转变为HfO2,说明在热处理温度高于573 K后NH4HfF5热稳定较差。多相法合成的NH4HfF5样品中19F-/16O-比值能达到35,180HfF5-离子束流能达到560 nA,优于液相和固相法合成的样品。     

磷酸钇共沉淀分离富集硫酸钴中痕量铁及铁的原子吸收光谱测定

共沉淀预浓集是原子光谱分析中有效的样品前处理技术之一，是提高原子吸收光谱测定灵敏度和选择性的有效手段。YPO4作为一种新型共沉淀捕集剂，最先由日本化学家Shigehiro Kagaya等提出，能够在弱酸性条件下对Pb、Fe选择性共沉淀，并且结构紧密，便于离心分离。根据这一特性，本实验采用YPO4共沉淀分离富集过渡金属盐CoSO4溶液中的痕量Fe^3 而后采用火焰原子吸收光谱测定的方法。     

电感耦合等离子体质谱测定铜精矿及废料中痕量锇同位素

样品经过碱熔氧化和蒸馏分离处理,用冰浴水吸收ＯｓＯ４,电感耦合等离子体质谱（ＩＣＰ－ＭＳ）测定纳克量６种Ｏｓ同位素。方法检出限为０．００１８μｇ／Ｌ￣０．０１５μｇ／Ｌ,加标回收率为９３．８％￣１０９．７％。     

离子色谱-质谱联用技术测定污泥样品中的痕量高氯酸盐

建立了离子色谱-质谱联用技术测定活性污泥样品中高氯酸盐的分析方法。以高容量、强亲水性的IonPacAS20(2mm)阴离子交换柱为分析柱,EGC在线产生等浓度KOH为淋洗液,淋洗液经抑制成水后将样品带入质谱检测。ESI-MS-MS以多元反应监测模式监控100.8/84.9、98.8/66.9、100.8/68.9和98.8/82.9离子对,以98.8/82.9离子对的峰面积进行定量。该方法对高氯酸盐的检出限(S/N=3)为0.01μg/L,高氯酸盐在0.05~100μg/L浓度范围内具有良好的线性,线性相关系数r=0.9988。0.2μg/L的标准溶液重复进样9次,高氯酸盐峰面积的相对标准偏差(RSD)为2.3%。运用该方法测定采自不同地区的活性污泥样品中的高氯酸盐,并对样品加标回收,得回收率在88.5%~102.2%之间。     

碱土金属盐中痕量铅的共沉淀分离富集及其机理研究

研究提出Ｃｕ（Ⅱ）＿ＰＤＣ在溶液ｐＨ２－１１时定量共沉淀碱土金属盐中的痕量铅,用ＦＡＡＳ测定,检出限可达１．５×１０＾２ｍｇ／Ｌ Ｐｂ（Ⅱ）,标准加入回收率在９８％－１０４％之间,克服了基体干扰,取得了较为满意的结果。同时对共沉淀机理进行了初步的研究探讨,结果表明其属于吸附共沉淀类型。     

共沉淀法辅助分离-离子色谱与电感耦合等离子体质谱联用测定玩具材料中三价铬及超痕量六价铬

采用0.07 mol/L盐酸萃取样品,取一部分萃取液用电感耦合等离子体质谱法(ICP-MS)测定可迁移总铬含量,另一部分萃取液通过Al(NO3)3共沉淀法去除高含量干扰阳离子后用离子色谱-电感耦合等离子体质谱联用法(IC-ICP-MS)测定六价铬(Cr(Ⅵ))含量,用可迁移总铬量减去Cr(Ⅵ)含量求得Cr(Ⅲ)含量,可迁移总铭及Cr(Ⅵ)的方法定量下限分别达0.01 mg/kg和0.003 mg/kg。选取2009/48/EC玩具新指令涉及的玩具材料进行加标及阳性样品验证,可迁移总铭及Cr(Ⅵ)的加标回收率分别为90.2%~101.5%和96.7%~106.7%,实验室间相对标准偏差分别不高于7.4%和7.9%。方法准确可靠,可实现玩具新指令所涉及的3类玩具材料中Cr(Ⅲ)及Cr(Ⅵ)的检测。     

土壤及蔬菜中微量汞的同位素稀释电感耦合等离子体质谱测定

建立了微波消解电感耦合等离子体质谱同位素稀释(ID/ICP-MS)测定微量汞的方法。考察了仪器参数及测量条件对汞同位素比值RHg(202Hg/200Hg)测量的影响,根据同位素比值测量误差的传递因子优化了富集同位素稀释剂(202Hg98%)的加入量,并以铊同位素比值(205Tl/203Tl)作为RHg(202Hg/200Hg)测量时发生质量歧视效应的校正因子;通过反同位素稀释法标定了富集汞同位素稀释剂的浓度。利用所建立的ID/ICP-MS方法测定了杨树叶(GBW07604)和湖积物(GBW07423)2种标准参考物中汞的含量,回收率分别为112%和100%。该方法具有准确度高、精密度好等优点,且样品前处理简便,适用于土壤及蔬菜等样品中微量及痕量汞的准确测定。     

电感耦合等离子体质谱(ICP-MS)法测定土壤中的碘

通过电感耦合等离子体质谱法(ICP-MS)测定土壤中的碘。样品预处理采用艾斯卡试剂熔融、热水提取和阳离子树脂静态交换,试验加入了不同剂量的阳离子交换树脂在不同程度上降低了溶液中Na+ 和Zn2+^{等阳离子的盐效应干扰。研究了乙醇在}ICP-MS中对碘元素的增强效应,用3%的氨水溶液清洗进样系统,有效减少的碘的记忆效应和清洗时间。该方法线性范围宽,方法灵敏度高,检出限低,试剂用量少,环境友好。对苏州及周边区域若干非污染土壤点位进行采样、制备和测试,碘平均含量为2.7μg.g_-1^;同步测试国家有证标准物质,精密度和准确度良好。     

化学分离－质谱法定量分析高纯Dy_2O_3中稀土杂质

以Ｐ_（５０７）萃淋树脂为固定相，ＨＣｌ－ＮＨ４Ｃｌ为淋洗液，研究了９９．９９９％～９９．９９９９％高纯Ｄｙ２Ｏ３中痕量稀土与基体Ｄｙ的分离法，以及火花源质谱法的测定条件。可分析９９．９９９９％超高纯Ｄｙ２Ｏ３中痕量稀土杂质，测定限０．００１～０．１×１０－６，误差３０％。     

Determination of 30 Free Fatty Acids in Two Famous Tibetan Medicines by HPLC with Fluorescence Detection and Mass Spectrometric Identification

A simple and sensitive high-performance liquid chromatographic (HPLC) method with fluorescence detection and mass spectrometric identification has been developed for analysis of 30 long-chain and short-chain free fatty acids (FFAs). The fatty acids were derivatized to their esters with 1-[2-(p-toluenesulfonate)ethyl]-2-phenylimidazole-[4,5-f]-9,10-phenanthrene (TSPP) in N,N-dimethylformamide (DMF) at 90 °C with anhydrous K₂CO₃ as catalyst. A mixture of C₁–C₃₀ fatty acids was completely separated within 60 min by gradient elution on a reversed-phase C₈ column. Qualitative identification of the acids was performed by atmospheric-pressure chemical ionization mass spectrometry (APCI–MS) in positive-ion mode. The fluorescence excitation and emission wavelengths were 260 and 380 nm, respectively. Quantitative determination of the 30 acids in two Tibetan medicines Gentiana straminea and G. dahurica was performed. The results indicated that the medicines contained many FFAs. Linear correlation coefficients for the FFA derivatives were >0.9991. Relative standard deviations (RSDs, n = 6) for the fatty acid derivatives were <3%. Detection limits (at a signal-to-noise ratio of 3:1) were 3.1–38 fmol. When the fatty acid derivatives were determined in the two real samples results were satisfactory and the sensitivity and reproducibility of the method were good.     

固液萃取-高效液相色谱-串联质谱法同时测定土壤中阿特拉津及其降解产物

建立了高效液相色谱-串联质谱法(HPLC-MS/MS)同时检测土壤中阿特拉津及其降解产物残留的分析方法。样品以甲醇-水(4∶1,V/V)作为提取溶剂,使用涡旋振荡提取,采用HPLC-MS/MS法进行测定,外标法定量。在0.01、0.2和5.0mg/kg三个添加浓度水平下,阿特拉津及其降解产物的平均回收率在73.7%~104.7%之间,相对标准偏差为0.4%~5.1%;阿特拉津,羟基阿特拉津在土壤样品中的方法检出限均0.045μg/kg,而脱乙基阿特拉津、脱乙基脱异丙基阿特拉津及脱异丙基阿特拉津在土壤样品中的方法检出限则分别为0.090、0.45和0.90μg/kg。本方法的灵敏度较高,且简便、快速,能较好的解决目标物极性差别大及样品基质对检测结果的干扰等问题,可以满足土壤中阿特拉津及其降解产物残留检测的需要。     

Simultaneous Determination of Multi-Class Pesticide Residues and PAHs in Plant Material and Soil Samples Using the Optimized QuEChERS Method and Tandem Mass Spectrometry Analysis

New analytical approaches to the simultaneous identification and quantification of 94 pesticides and 13 polycyclic aromatic hydrocarbons (PAHs) in five representative matrices (pepper, apple, lettuce, wheat, and soil) were developed. The analyses were based on gas chromatography coupled with triple quadrupole tandem mass spectrometry (GC-MS/MS). The procedure was optimized by changing the solvent used during the extraction, from acetonitrile to the acetone: n-hexane mixture at a volume ratio of 1:4 (v/v), as well as the use of a reduced amount of water during the extraction of compounds from cereals. An additional modification was the use of florisil instead of GCB in the sample cleanup step. A full method validation study was performed, at two concentration levels (LOQ and 1000 × LOQ), which showed satisfactory results for all analytes from the PAHs group, with recoveries ranging from 70.7–115.1%, and an average RSD of 3.9%. Linearity was tested in the range of 0.001–1.000 mg/kg and showed coefficients of determination (R²) ≥ 0.99 for all PAHs. Satisfactory recovery and precision parameters (LOQ and 100 × LOQ) were achieved for almost all analytes from the pesticide group in the range of 70.1–119.3% with the mean RSD equal to 5.9%. The observed linearity for all analytes in the concentration range of 0.005–1.44 mg/kg was R² ≥ 0.99, with the exception of famoxadone, chizalofop-p-ethyl, prothioconazole, spirodiclofen, tefluthrin, and zoxamid. The extended uncertainties were estimated, using a top-down approach of 9.9% (average) and 15.3% (average) for PAHs and pesticides samples, respectively (the coverage factor k = 2, the 95% confidence level). Ultimately, the method was successfully applied to determine pesticide residues in commercial samples of fruit, vegetables and grain, and soil samples for PAHs, which were collected from selected places in the Podkarpacie region. A total of 38 real samples were tested, in which 10 pesticides and 13 PAHs were determined. Proposed changes allow us to shorten the sample preparation time (by 20%) and to reduce the consumption of organic solvents (by 17%). The use of florisil for sample cleanup, instead of GCB, improves the recovery of compounds with flat particles.     

反反相色谱-串联质谱法直接测定植物源性食品中草甘膦及其代谢物残留

采用反反相色谱-串联质谱法建立了直接测定植物源性食品中草甘膦(GLY)及其主要代谢物氨甲基膦酸(AMPA)的方法。样品用水提取,阴离子交换柱(MAX)净化,以5 mmol/L的乙酸铵溶液和5%水-95%乙腈的乙酸铵溶液为流动相,反反相色谱分离,采用电喷雾离子源、负离子扫描模式和多反应监测模式质谱检测,外标法定量。草甘膦和氨甲基膦酸的线性范围分别为10～500μg/L和20～1 000μg/L,相关系数(r2)均大于0.99。方法的检出限(S/N=3)均为0.01 mg/kg,定量下限(S/N=10)分别为0.02 mg/kg和0.04 mg/kg。在6种基质中,GLY和AMPA在3个加标水平下的回收率为78%～113%,相对标准偏差(RSD,n=6)为3.2%～11.0%。方法的灵敏度和回收率高,选择性好,能满足日常食品检测工作的要求。     

Sensitive and Selective Spectrophotometric Determination of Hg(II), Ni(II), Cu(II) and Co(II) Using Iminodibenzyl and 3-Chloroiminodibenzyl as New Reagents and Their Applications to Industrial Effluents and Soil Samples

Iminodibenzyl (IDB) and 3-chloroiminodibenzyl (Cl-IDB) are proposed as a new class of spectrophotometric reagents for the determination of micro amounts of mercury(II), nickel(II), copper(II) and cobalt(II) in the presence of 3-methyl-2-benzothiazoline hydrazone hydrochloride hydrate (MBTH) or 4-aminoantipyrine (AAP) as electrophilic coupling reagents. The reaction is carried out in neutral aqueous medium. The blue colour formed shows maximum absorbance at 660 nm using MBTH and 630 nm with AAP. The methods obey Beer's law. The molar absorptivity and Sandell's sensitivity show different values with different metals and reagents. The blue colour can also be extracted quantitatively which can be exploited as an efficient extractive spectrophotometric technique for the separation of metal ion from other interfering species. As many as 15 cations and 12 anions and/or complexing agents listed do not interfere. Both the methods have good reproducibility and can be satisfactorily applied in the determination of metals in industrial effluents and soil samples.     

Determination of Herbicides in Natural Waters Using Solid Phase Microextraction (SPME) and Gas Chromatography Coupled with Flame Thermionic and Mass Spectrometric Detection

Abstract

This study develops a method for solid phase microextraction (SPME) of ten widespread herbicides from water. The selected herbicides belong to different chemical groups are EPTC, molinate, propachlor, trifluralin, atrazine, propazine, terbuthylazine, prometryne, alachlor. Their determination was carried out by gas chromatography with flame thermionic and mass spectrometric detection. To perform the SPME, two types of fibre have been assayed: Carbowax-divinylbenzene (CW-DVB) of 65 μm thickness and polydimethylsiloxane-divinylbenzene (PDMS-DVB) of 65 μm thickness. The main factors affecting the SPME process such as pH, ionic strength, methanol content, memory effect, stirring rate and adsorption-time profile were studied. The method was applied to spiked natural waters such as ground water, sea water, lake water and river water in a concentration range of 0.1 to 10 μg/L. Limits of detection with each of the detectors were determined to be 1 – 20 ng/L in PDMS-DVB and 2–20 ng/L CW-DVB fibres. The recoveries of herbicides compared to distilled water were in relatively high levels 78.3–127.3 % and the average r² values of the calibration curves were above 0.99 for all the analytes. The SPME conditions were finally optimized in order to obtain maximum sensitivity and samples were applied for the trace-level determination in river water samples originating from Ioannina region (Greece).     

碱消解-离子色谱与电感耦合等离子体质谱(IC-ICP-MS)法测定土壤中的六价铬

采用碱消解土壤溶液提取土壤溶液中的六价铬,用离子色谱(IC)进行分离,有效避免了高盐及焰色反应的干扰,电感耦合等离子体质谱(ICP-MS)法进行检测。研究了消解液使用量、消解温度、消解时间等因素,测定结果和火焰原子吸收光谱(FAAS)法进行对比。结果表明,当称样量为5.0 g,消解液40.0 mL,磷酸缓冲溶液0.4 mL,无水氯化镁0.4 g,消解温度在90～95℃范围内消解0.75 h能保证土壤中六价铬的完全提取。方法检出限为0.01 mg/kg,相对标准偏差为3.5%,土壤标准物质的回收率为92.4%;与FAAS法(检出限0.35 mg/kg,精密度为6.3%)相比,检出限更低,精密度更好,抗干扰能力强;通过实际样品的测定结果统计学检验,两种方法结果无显著性差异;方法适用于土壤中低浓度六价铬的测定。