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1.
应用气相色谱-质谱法确证及测定谷物(糙米、玉米)中噻吩甲氯的残留含量,试样采用水-丙酮提取,提取液经与石油醚液-液分配后,再以硅酸镁载体(Florisil)柱净化,气相色谱-质量选择检测器选择离子监测方式(GC-MSD-SIM)进行测定和阳性确证。噻吩甲氯选择监测离子的种类为m/z287、288、323,其丰度比约为46∶100∶11。采用外标法定量,方法检出限为0.010×10  相似文献   

2.
提出了用新试剂1-(对偶氮苯)-3-(2-吡啶)-三氮烯分光光度法测定镍的方法,研究结果表明,显色反应有很好的选择性,常见离子除镉外,基本上不干扰。  相似文献   

3.
报道了饱和漆酚30-冠-10轻稀土(Ln=La~Nd)配合物的合成,通过元素分析、IR、UV、摩尔电导和DTA等方法对配合物进行了表征;并以饱和漆酚冠醚为传感活性物质,研制了镧(Ⅲ)离子选择电极,它的线性响应范围为1×10-2~1×10-6mol/LLa(NO3)3,检测下限为1×10-6mol/LLa(NO3)3,对镧离子的选择优于其他镧离子电极。  相似文献   

4.
氯铝酸离子液体介质中醚化反应的研究   总被引:3,自引:0,他引:3  
乔焜  邓友全 《催化学报》2002,23(6):559-561
 在1-烷基吡啶、1-甲基-3-烷基咪唑季铵盐或盐酸三甲铵与无水AlCl3构成的室温离子液体反应介质中,尝试进行了叔丁醇的醚化反应.结果表明,在中性或碱性氯铝酸离子液体中,叔丁醇与甲醇、乙醇、丙醇、丁醇或戊醇在80~140℃反应6~12h,可以得到较高的醇转化率和醚选择性,而且产物叔丁基醚和离子液体系分层,便于分离.  相似文献   

5.
徐友宣  申利 《分析化学》1997,25(1):63-65
采用液-液萃取结合GC/MS选择离子的方法,建立了人尿中8种合成麻醉镇痛剂的分析方法,讨论了回收率和检测限问题,并成功地用于实际尿样检测。  相似文献   

6.
侯艳文  牟世芬 《分析化学》1997,25(11):1241-1245
提出了用离子色谱柱后衍生法同时测定汞和其它金属离子的新方法。本方法中样品离子以阴离子交换分离,用2-(5-溴-2-吡啶偶氮)-5-二乙氨基酚和非离子表面活性剂TritonX-100显色体系作柱后衍生,分光光度法测定。  相似文献   

7.
镉离子选择电极电位滴定测定钙镁   总被引:2,自引:0,他引:2  
建立了以镉离子选择电极极作指示电极EDTA、EGTA电位滴定测定钙、镁的方法,详细考察了电位滴定的适宜条件,干扰离子的影响及消除办法。在四硼酸钠-氢氧化钠缓冲介质中,EGTA滴定钙,EDTA滴定钙镁含量,测定矿泉水及硅酸盐样品中钙镁含量,结果符合要求。  相似文献   

8.
以苯酚为起始剂,用先聚合后功能基化和Na^ 离子模板的简捷方法合成了一种新型聚合物-氮杂假冠醚,研究了其对金属离子的静态吸附性能,结果表明,聚合物对Na^ 和Ca^2+离子具有良好的选择吸附性能,对浓度为0.026mol/L-0.028mol/L的Na^ 和Ca^2 的静态吸附容量分别达2.54mmol/g和3.06mmol/g;通过红外光谱研究了聚合物及其与Na^ 和Ca^2 的配合物的结构,结果表明,在吸附聚合物中,不仅-CH2OCH2-和-CH2NCH2-参与了配位,-CH2OH和PhOCH2-亦不同程度地参与了配位。  相似文献   

9.
姜浩  姜泓  江骥  钟大放 《分析化学》2002,30(12):1431-1434
应用高效液相色谱-电喷雾离子阱质谱法鉴定了人口服奥美拉唑(OPZ)后0-6h内尿中的代谢物。尿中代谢物经富集后,应用高效液相色谱法分离,然后在线进行选择离子扫描(SIM)、二级碎片离子全扫描(full scan MS^2)和三级碎片离子全扫描(full scan MS^3),进行对尿中微量的烷烃羟基化、O-脱烷烃化、硫氧化和还原以及葡萄糖醛酸化和硫酸化的9种代谢物进行了质谱解析。  相似文献   

10.
硬膏剂中甲苯残留的吹扫—捕集GC—MS测定方法   总被引:1,自引:0,他引:1  
建立了一种吹扫-捕集进样与气相色谱-质谱联用、选择离子监测的方式,测定样品中甲苯溶剂残留的方法。该法操作方便、简单。方法相对标准偏差为375%,平均回收率为957%。适用于医药、食品包装等行业甲苯残留的检测。  相似文献   

11.
In order to determine PAHs in marine sediment samples by GC/MS(SIM) a new extraction approach of ASE-SFE was evaluated using combined accelerated solvent extraction (ASE, dynamic and static mode) and supercritical fluid extraction (SFE, dynamic mode) without further purification of the sample. The solvents used for ASE-SFE were methylene chloride and carbon dioxide. The recovery data, precision and accuracy of the whole method were evaluated statistically. The average recoveries of PAHs, based on deuterated internal standards were 77% for 2-3-ring PAHs, 85% for 4-ring PAHs, 88% for 5-ring PAHs and 97% for 6-ring PAHs. The extraction time required for the ASE-SFE technique was 30 min, which is longer than in the case of independent use of ASE and shorter compared to SFE. ASE-SFE recoveries of PAHs from SRM marine sediment are comparable for (2-3-ring, 4-ring PAHs) or higher (5-ring, 6-ring PAHs) than reported for the conventional extraction methods of ASE and SFE. Method detection limits of (MDL) were statistically estimated. MDL values obtained for 15 PAHs compounds vary between 0.06 ngg(-1) and 3.54 ngg(-1).  相似文献   

12.
In order to determine PAHs in marine sediment samples by GC/MS(SIM) a new extraction approach of ASE-SFE was evaluated using combined accelerated solvent extraction (ASE, dynamic and static mode) and supercritical fluid extraction (SFE, dynamic mode) without further purification of the sample. The solvents used for ASE-SFE were methylene chloride and carbon dioxide. The recovery data, precision and accuracy of the whole method were evaluated statistically. The average recoveries of PAHs, based on deuterated internal standards were 77% for 2–3-ring PAHs, 85% for 4-ring PAHs, 88% for ¶5-ring PAHs and 97% for 6-ring PAHs. The extraction time required for the ASE-SFE technique was 30 min, which is longer than in the case of independent use of ASE and shorter compared to SFE. ASE-SFE recoveries of PAHs from SRM marine sediment are comparable for (2–3-ring, 4-ring PAHs) or higher (5-ring, 6-ring PAHs) than reported for the conventional extraction methods of ASE and SFE. Method detection limits of (MDL) were statistically estimated. MDL values obtained for 15 PAHs compounds vary between 0.06 ngg?1 and 3.54 ngg?1.  相似文献   

13.
Two new marine sediment standard reference materials (SRMs), SRM 1941b Organics in Marine Sediment and SRM 1944 New York/New Jersey Waterway Sediment, have been recently issued by the National Institute of Standards and Technology (NIST) for the determination of organic contaminants including polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyl (PCB) congeners, and chlorinated pesticides. Both sediment SRMs were analyzed using multiple analytical methods including gas chromatography/mass spectrometry (GC/MS) on columns with different selectivity, reversed-phase liquid chromatography with fluorescence detection (for PAHs only), and GC with electron capture detection (for PCBs and pesticides only). SRM 1941b has certified concentrations for 24 PAHs, 29 PCB congeners, and 7 pesticides, and SRM 1944 has certified concentrations for 24 PAHs, 29 PCB congeners, and 4 pesticides. Reference concentrations are also provided for an additional 58 (SRM 1941b) and 39 (SRM 1944) PAHs, PCB congeners, and pesticides. SRM 1944, which was collected from multiple sites within New York/New Jersey coastal waterways, has contaminant concentrations that are generally a factor of 10–20 greater than SRM 1941b, which was collected in the Baltimore (Maryland) harbor. These two SRMs represent the most extensively characterized marine sediment certified reference materials available for the determination of organic contaminants.Electronic Supplementary Material Supplementary material is available in the online version of this article at . A link in the frame on the left on that page takes you directly to the supplementary material.  相似文献   

14.
Polycyclic aromatic hydrocarbons (PAHs) are frequently measured in the atmosphere for air quality assessment, in biological tissues for health-effects monitoring, in sediments and mollusks for environmental monitoring, and in foodstuffs for safety reasons. In contemporary analysis of these complex matrices, gas chromatography (GC), rather than liquid chromatography (LC), is often the preferred approach for separation, identification, and quantification of PAHs, largely because GC generally affords greater selectivity, resolution, and sensitivity than LC. This article reviews modern-day GC and state-of-the-art GC techniques used for the determination of PAHs in environmental samples. Standard test methods are discussed. GC separations of PAHs on a variety of capillary columns are examined, and the properties and uses of selected mass spectrometric (MS) techniques are presented. PAH literature on GC with MS techniques, including chemical ionization, ion-trap MS, time-of-flight MS (TOF-MS), and isotope-ratio mass spectrometry (IRMS), is reviewed. Enhancements to GC, for example large-volume injection, thermal desorption, fast GC, and coupling of GC to LC, are also discussed with regard to the determination of PAHs in an effort to demonstrate the vigor and robustness GC continues to achieve in the analytical sciences.  相似文献   

15.
The potential of gas chromatography coupled to tandem mass spectrometry (GC/MS/MS) with a triple quadrupole analyzer (QqQ) has been investigated for the quantification and reliable identification of sixteen polycyclic aromatic hydrocarbons (PAHs) from the EPA priority list in animal and vegetable samples from aquaculture activities, whose fat content ranged from 5 to 100%. Matrices analyzed included fish fillet, fish feed, fish oil and linseed oil. Combining optimized saponification and solid‐phase extraction led to high efficiency in the elimination of interfering compounds, mainly fat, from the extracts. The developed procedure minimized the presence of these interfering compounds in the extracts and provided satisfactory recoveries of PAHs. The excellent sensitivity and selectivity of GC/(QqQ)MS/MS in selected reaction monitoring (SRM) allowed to reach limits of detection at pg/g levels. Two SRM transitions were acquired for each analyte to ensure reliable identification of compounds detected in samples. Confirmation of positive findings was performed by GC coupled to high‐resolution time‐of‐flight mass spectrometry (GC/TOFMS). The accurate mass information provided by GC/TOFMS in full acquisition mode together with its high mass resolution makes it a powerful analytical tool for the unequivocal confirmation of PAHs in the matrices tested. The method developed was applied to the analysis of real‐world samples of each matrix studied with the result of detecting and confirming the majority of analytes at the µg/kg level by both QqQ and TOF mass spectrometers. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

16.
建立了快速溶剂萃取(ASE)-气相色谱-串联质谱(GC-MS/MS)分析海洋沉积物中16种多环芳烃(PAHs)的分析方法。样品由正己烷-丙酮(1∶1,v/v)溶液萃取,经无水硫酸钠脱水、氮吹浓缩后,采用硅胶固相萃取小柱进行净化,然后经HP-5MS色谱柱(30 m×0.25 mm×0.25 μm)分离,在电子轰击电离源下以多反应监测(MRM)模式进行检测,内标法定量。分析结果表明,16种PAHs在0.01~1.00 mg/L范围内线性关系良好,相关系数(R)大于0.997;目标物的加标回收率为75.8%~97.8%;日内与日间精密度(RSD)均小于10%。当取样量为20.0 g时,16种PAHs的方法检出限为0.048~0.234 μg/kg。该法快速、准确、稳定,能够满足海洋沉积物中痕量PAHs的测定。  相似文献   

17.
多环芳烃指纹用于渤海采油平台原油的鉴别   总被引:5,自引:0,他引:5  
采用气相色谱/质谱方法,对渤海海上4个不同区块、5个平台的6口油井原油进行了烷基化多环芳烃系列化合物和美国环保署(EPA)优先控制多环芳烃系列化合物的准确定性定量分析。通过多环芳烃原始指纹谱图、多环芳烃组分分布模式和特征比值的比较对上述原油进行鉴别。结果证明不同区块的原油中多环芳烃指纹信息不尽相同,即使在同一平台不同油井中所产的原油其指纹也存在一定差异。为确保原油鉴别的准确性,分析过程中必须在仪器的稳定性和样品前处理方面实施严格的质量控制措施。  相似文献   

18.
Microprobe two-step laser desorption/laser ionization mass spectrometry (μL2MS) and gas chromatography/mass spectrometry (GC/MS) were used to analyze polycyclic aromatic hydrocarbons (PAHs) in ancient terrestrial rocks. μL2MS provides an in situ analysis of very small samples, records the PAHs with no isomer information, and gives quantitative data on the degree of alkylation of a given PAH series over the complete mass range. GC/MS provides isomer separation and quantitation of PAHs in bitumen but not kerogen, and is limited by sample size. Combination of these techniques allows analysis of very small samples by μL2MS with GC/MS confirmation of isomer distributions of the solvent extractable components (bitumen). It was found that the concentration of bitumen within the rock samples affects the PAH alkylation signal for μL2MS. At low bitumen concentrations μL2MS can produce pyrolysis products from kerogen that is present; however, as bitumen concentrations increase, the PAH distribution from bitumen dominates the signal.  相似文献   

19.
气质联用仪测定电子电气产品中多环芳烃   总被引:1,自引:0,他引:1  
建立了以甲苯溶剂超声波震荡提取、离心机分离萃取液、气相色谱-质谱联用仪测定电子电气产品中16种多环芳烃组分的方法,萃取条件为:用甲苯溶剂在60℃超声波震荡60 min,外标法定量。各组分的浓度在10~500ng/mL范围内具有良好的线性,线性相关系数r2大于0.994,检出限为0.05~0.30 mg/kg。方法的加标回收率为80%~120%,测定结果的相对标准偏差小于5%。  相似文献   

20.
Thermal desorption coupled with gas chromatography/mass spectrometry (TD-GC/MS) is an alternative to solvent extraction (SE)-based GC/MS (SE-GC/MS) for the analysis of non-polar organic compounds in filter or impactor-collected aerosols. TD-GC/MS has no sample pretreatment and requires a small filter aliquot for detecting individual organic compounds. The performance of an in-injection port TD-GC/MS is evaluated for polycyclic aromatic hydrocarbons (PAHs), n-alkanes, iso-/anteiso-alkanes, hopanes, steranes, branched alkanes, cyclohexanes, alkenes, and phthalates in standards and ambient air samples. Replicate analysis for 132 organic compounds showed relative standard deviations <10%, with the majority <5%. Accuracy for 15 PAHs, determined with NIST standard reference material (SRM) 1649a urban dust, was within +/-5% of the certified values. TD-GC/MS and SE-GC/MS method comparisons for 14 Hong Kong ambient samples agreed within 11% for 106 non-polar compounds. For 19 Tong Liang, China samples, agreement was within 13% for 23 PAHs.  相似文献   

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