液相微萃取-气相色谱/质谱测定水中硝基苯类化合物

建立了水中硝基苯类化合物(硝基苯、1-硝基甲苯、2-硝基甲苯、3-硝基甲苯和邻氯硝基苯)的液相微萃取-气相色谱/质谱检测方法。实验结果显示:甲苯为最佳的萃取剂。确定最佳实验条件为:甲苯体积2μL,萃取时间15 min,搅拌速度300 r/min,萃取温度45℃,溶液pH=5。在此条件下,各目标物的萃取富集倍数为30~38,线性范围为2~250μg/L,检出限为1~2μg/L,测定的相对标准偏差为5%~7%。     

固相微萃取-气相色谱-质谱联用测定水中酚类化合物

建立了固相微萃取与气相色谱－质谱联用技术（SPME－GC－MS）测定水中酚类化合物的新方法，探讨了萃取时间、搅拌速度、离子强度、pH值和解吸时间等条件对萃取量的影响。结果表明：65μm PDMS/DVB涂层对水中的酚类化合物有较好的萃取效果，用于水中酚类化合物的测定，结果满意。     

磁性分散固相萃取气相色谱法测定地表水中硝基苯类

建立了一种磁性分散固相萃取气相色谱法快速测定地表水中硝基苯类化合物的分析方法,并优化了磁性萃取材料的用量、萃取的时间、解吸溶剂的选择、盐效应等试验影响因素.试验结果表明,硝基苯类化合物的检出限为0.000 4~0.007 mg/L,回收率为84.0%~97.6%,相对标准偏差为3.4%~5.3%.方法具有适用性广、溶剂用量少和操作简便等特点,能很好的测定地表水中的硝基苯类化合物.     

固相萃取-气相色谱法测定水中毒死蜱

水样中的毒死蜱经全自动固相萃取仪萃取、乙酸乙酯洗脱后,用气相色谱火焰光度检测法测定,以保留时间定性,外标法定量．结果表明：选用ENVI-18小柱萃取、乙酸乙酯洗脱,在2mL／min的过水速率下取得了良好的回收率．方法的线性范围为0．25～4．0mg／L．r为0．9998,回收率为88．6％～100．6％,相对标准偏差为2．58％～7．34％,最低定量浓度为2．5μg／L．本方法快速、灵敏、准确,并能够很好的排除干扰,可以满足水中痕量毒死蜱的测定．     

固相萃取-气相色谱质谱联用法测定蔬菜中杜烯残留

建立固相萃取-气相色谱-质谱联用内标法测定蔬菜中杜烯残留量的检测方法.样品经乙腈提取,弗罗里硅土固相柱净化后,用气相色谱质谱联用仪进行检测.方法的检出限为0.005 mg/kg,经过不同实验室验证,样品中杜烯的平均基体添加回收率在81.0%～112.0%之间,室间精密度在1.03%～3.89%之间.     

环境水样中9种三唑类农药的固相萃取-气相色谱-质谱分析

应用C18柱萃取/富集,NH2柱净化,气相色谱-质谱联用技术检测,建立了环境水样中9种三唑类农药同时分析的方法。9种目标农药在0.025～0.500 mg/L质量浓度范围内线性关系良好,方法的检出限为0.002～0.009 μg/L。以实际水样为基底,加标质量浓度为0.025 μg/L和0.100 μg/L时,9种目标农药的基底加标回收率和相对标准偏差(n=3)分别为68.4%～113.9%,1.6%～6.9%(河水)和70.3%～115.2%,0.8%～8.2%(海水)。该方法操作简单、灵敏度高、选择性好,符合多种农药残留分析的要求,并成功地应用于福建九龙江河口区表层水样中三唑类农药的残留状况调查。     

分散固相萃取-气相色谱-质谱联用法测定水产品中的痕量酮麝香

建立了水产品中痕量酮麝香测定的分散固相萃取-气相色谱-质谱联用法(GC-MS)。目标化合物经1%乙酸-乙腈高速匀浆提取,以N-丙基乙二胺(PSA)、C₁₈和石墨化碳(GCB)混合物为分散剂对其进行净化,采用GC-MS在选择离子监测模式下测定,外标法定量,并应用正交试验对前处理条件进行优化,以及对酮麝香的裂解机制进行探讨。在优化条件下,方法在1～50 μg/L范围内线性关系良好,相关系数不低于0.999,检出限(S/N=3)为0.30 μg/kg。对于明虾和罗非鱼空白样品,在1.0、2.0、10.0 μg/kg 3个水平下的加标回收率为91.8%～110.6%,相对标准偏差(RSD)为2.6%～8.4%。该方法操作简便、快速、准确,可用于水产品中痕量酮麝香的日常检验。     

固相萃取-气相色谱-质谱联用法测定食品中丙环唑残留量

提出了18种食品基质中丙环唑残留量的气相色谱-质谱联用分析方法。样品中丙环唑利用乙腈或乙酸乙酯提取,C18和活性炭串联固相萃取柱净化,采用DB-1701弹性毛细管色谱柱进行分离。采用气相色谱-质谱电子轰击电离源和选择离子监测模式进行测定。在0.02～5.0mg.L-1范围内丙环唑标准溶液的峰面积与浓度呈线性关系(r=0.9995),在0.01,0.02,0.05mg.kg-13个添加水平下丙环唑的回收率在70%～115%之间,相对标准偏差(n=6)小于10.2%,检出限(3S/N)为0.004mg·kg-1。     

配位聚合物固相萃取/气相色谱-质谱联用法测定环境水样中的6种多环芳烃

制备了一种二维的[Zn(benzotriazole)2]n配位聚合物,并经过XRD、SEM及元素分析法的表征,将其用于富集萃取环境水样中的6种重质多环芳烃,该配合物对于含多苯环的化合物显示出较强的吸附力。实验中分别对填料用量、淋洗剂、洗脱剂的种类及用量、穿透体积等参数进行考察,并将其与同等上样量及加标量的C18固相萃取小柱进行对比,建立了水样中6种多环芳烃的气相色谱-质谱联用检测方法。结果表明,使用200mg[Zn(benzotriazole)2]n配合物作为固相萃取填料,以10%甲醇为淋洗剂,0.5mL丙酮和5mL二氯甲烷作为洗脱剂,在上样体积为200mL、流速为4mL/min的条件下,6种多环芳烃均具有较高的回收率。荧蒽(Flan)、苯并(b)荧蒽(BbF)、苯并(g,h,i)芘(BghiP)的质量浓度在20～1000μg/L范围内,苯并(k)荧蒽(BkF)、苯并(a)芘(BaP)、茚并(1,2,3-Cd)芘(InP)在10～500μg/L范围内与峰面积呈良好线性关系,相关系数为0.9968～0.9993。方法的检出限为0.45～10.7ng/L,加标回收率为77%～112%,相对标准偏差为3.8%～8.5%。结果表明,该方法具有成本低、灵敏度高等特点,能够满足实际水样中6种多环芳烃的测定要求。     

固相微萃取/气相色谱-质谱联用法测定橡胶密封材料中N-亚硝胺

建立了固相微萃取/气相色谱-质谱联用法(SPME/GC-MS)测定橡胶密封材料中N-亚硝基-N-甲基苯胺(NMPh A)、N-亚硝基-N-乙基苯胺(NEPh A)和N-亚硝基二苯基胺(NDPhe A)3种N-亚硝胺化合物含量的方法。样品参考国标GB/T 24153-2009进行预处理后,采用固相微萃取进行提取,对影响固相微萃取效率的纤维涂覆种类、萃取时间、搅拌速度和萃取温度等条件进行优化。在优化条件下,方法的线性范围为5~500μg/L,相关系数(r)均大于0.99,检出限为0.5μg/kg,回收率为77%~92%,相对标准偏差(RSD,n=6)为3.8%~7.7%。     

Determination of chloro-s-triazines including didealkylatrazine using solid-phase extraction coupled with gas chromatography-mass spectrometry

Chloro-s-triazines are a class of compounds comprising atrazine, simazine, propazine, cyanazine and their chlorinated metabolites. The US Environmental Protection Agency (EPA) has determined that selected chloro-s-triazines--atrazine, simazine, propazine, deethylatrazine, deisopropylatrazine, and didealkylatrazine--have a common mode of toxicity related to endocrine disruption. In this paper, a dual-resin solid-phase extraction (SPE) gas chromatography-mass spectrometry (GC-MS) method is reported that provides for each of these chloro-s-triazines including the polar metabolite, didealkylatrazine. The method utilizes deuterated internal standards for quantitation and terbuthylazine as a recovery standard. The limit-of-detection was 0.01 microg/L for simazine, deethylatrazine, deisopropylatrazine and didealkylatrazine, and 0.02 microg/L for atrazine and propazine in surface water. Mean recoveries for 0.5 and 3.0 microg/L spikes for atrazine, simazine, propazine, deethylatrazine, deisopropylatrazine and didealkylatrazine were 94, 104, 103, 110, 108 and 102%, respectively, in surface water. The method was also validated by matrix spikes into fourteen different raw and treated natural surface waters. This method is useful for monitoring "total chloro-s-triazines" in both raw and treated drinking waters.     

Determination of nitrosamines in water by gas chromatography/chemical ionization/selective ion trapping mass spectrometry

A gas chromatography/mass spectrometry (GC/MS) method for determination of nine N-nitrosamines (NAs) in water is described. Two ionization modes, electron impact (EI) and chemical ionization (CI) with methanol, as well as different ion analysis techniques, i.e. full scan, selected ion storage (SIS) and tandem mass spectrometry (MS/MS) were tested. Chemical ionization followed by SIS resulted the mass spectrometric method of choice, with detection limits in the range of 1-2ng/L. Solid Phase Extraction (SPE) with coconut charcoal cartridges was applied to extract NAs from real samples, according EPA Method 521. Drinking water samples were collected from seven surface- and two groundwater treatment plants. Three surface water treatment plants were sampled before and after addition of O(3)/ClO(2) to observe the effect of disinfection on NAs' formation. N-nitrosodiethylamine (NDEA), n-nitrosodipropylamine (NDPA), n-nitrosomorpholine (NMOR) and n-nitrosodibutylamine (NDBA) were found up to concentrations exceeding three times the risk level of 10ng/L set by the California Department of Public Health. Because dermal adsorption has been recently indicated as a new contamination route of exposure to NAs for people who practice swimming activity, water samples from five swimming pools in the Bologna (Italy) area were collected. N-nitrosopyrrolidine (NPYR) was detected in all samples at concentrations larger than 50ng/L, likely as a disinfection by-product from the amino acid precursor proline, a main constituent of skin collagen.     

Determination of pesticides in water samples by solid phase extraction and gas chromatography tandem mass spectrometry

A multiresidue method for the determination of more than 80 pesticides in water has been developed and validated. The proposed method is based on SPE followed by GC coupled to MS/MS. Different variables affecting SPE procedure, such as cartridges, sample volume and solvents were studied, and mass spectrometric conditions were optimised in order to increase selectivity and sensitivity. Calibration curves were linear over the range of 0.03-0.5 microg/L. Recoveries were in the range of 70-110% and repeatability was below 20% for the lowest calibration point. LODs ranged from 0.001 to 0.025 microg/L and LOQs from 0.003 to 0.076 microg/L. Finally, the method was successfully applied to the analysis of water samples from southeast of Spain.     

Continuous solid-phase extraction and gas chromatography–mass spectrometry determination of pharmaceuticals and hormones in water samples

A semi-automatic flow-based method for the simultaneous determination of 9 pharmaceuticals and 3 hormones in water samples in a single analytical run is proposed. The analytes were retained on a solid-phase extraction sorbent column and 1 μL of the eluate analysed by gas chromatography in combination with electron impact ionization mass spectrometry in the SIM mode. The sorbent used, Oasis-HLB, provided near-quantitative recovery of all analytes. The proposed method was validated with quite good analytical results including low limits of detection (0.01–0.06 ng L⁻¹ for 100 mL of water) and good linearity (r² > 0.993) throughout the studied concentration ranges. The method provided good accuracy (recoveries of 85–103%) and precision (between- and within-day RSD values less than 7%) in the determination of the pharmaceuticals and hormones in tap, river, pond, well, swimming pool and wastewater.     

Analysis of earthy and musty odors in water samples by solid-phase microextraction coupled with gas chromatography/ion trap mass spectrometry

A method for the determination of the earthy and musty odors geosmin, 2-methylisoborneol (2-MIB), 2-isobutyl-3-methoxy pyrazine (IBMP), 2-isopropyl-3-methoxy pyrazine (IPMP) and 2,4,6-trichloroanisole (2,4,6-TCA) in water by headspace solid-phase microextraction (HSSPME) combined with gas chromatography-ion trap mass spectrometry (GC-ITMS) is described. Several parameters of the extraction and desorption procedure were studied and optimized (such as types of fibers, extraction temperature, extraction time, desorption temperature, desorption time, ionic strength and elutropic strength and pH of samples). The method shows good linearity over the concentration range 1-500 ng l⁻¹ and gives detection limits of sub-part per trillion levels for all compounds. Good precision (5.9-9.8%) is obtained using IBMP as internal standard. Finally, the method was successfully applied to analyze earthy and musty odors in tap water and lake water.     

Determination of gaseous carbonyl compounds by their pentafluorophenyl hydrazones with gas chromatography/mass spectrometry

A sensitive and reliable method has been developed for the simultaneous determination of 20 airborne carbonyl compounds in the C₁-C₁₀ range. The carbonyls were collected onto solid sorbent coated with pentafluorophenyl hydrazine (PFPH), followed by solvent extraction and gas chromatographic (GC)/mass spectrometric (MS) analysis of the PFPH derivatives. The sorbent is packed into two separate sections in a glass sampling tube. The two-section design allows convenient checking of collection efficiency and breakthrough. The sampling tube, with a coating amount of 971 nmol PFPH per 100 mg Tenax TA and operated at a sampling flow rate of 80 mL min⁻¹, collects the 20 carbonyls with efficiencies above 95%. Hexane extracts the collected carbonyls in their PFPH derivatives in the sampling tube with better than 95% extraction efficiency. It is necessary to let the sampling tube sit at ambient temperature for 3 days before solvent extraction to ensure complete derivatization of the carbonyls. The limits of detection (LODs) of the tested carbonyls are in the range of 3.7-11.6 ng per sample. The method has been field-tested both in ambient environment and in an indoor environment from burning mosquito-repellent incense. Eighteen carbonyls were detected in the ambient air samples with the exception of o-tolualdehyde and m-tolualdehyde, while all the 20 target carbonyls were found in the incense smoke. Compare field test with classical DNPH-HPLC/UV method, good agreement exited between the two methods for lower molecular carbonyls but PFPH method is found to be a better analytical method for determination of high molecular weight carbonyls.     

Determination of antimicrobial residues and metabolites in the aquatic environment by liquid chromatography tandem mass spectrometry

Antimicrobials are used in large quantities in human and veterinary medicine. Their environmental occurrence is of particular concern due to the potential spread and maintenance of bacterial resistance. After intake by the organisms, the unchanged drug and its metabolized forms are excreted and enter wastewater treatment plants where they are mostly incompletely eliminated, and are therefore eventually released into the aquatic environment. The reliable detection of several antimicrobials in different environmental aqueous compartments is the result of great improvements achieved in analytical chemistry. This article provides an overview of the more outstanding analytical methods based on liquid chromatography tandem mass spectrometry, developed and applied to determine antimicrobial residues and metabolites present in surface, waste, and ground waters.      

Determination of priority organic micro-pollutants in water by gas chromatography coupled to triple quadrupole mass spectrometry

A multiclass method has been developed for screening, quantification and confirmation of organic micro-pollutants in water by gas chromatography coupled to mass spectrometry with a triple quadrupole analyzer. The work has been focused on the determination of more than 50 compounds belonging to different chemical families: 19 organochlorine and organophosphorus insecticides, 6 herbicides, 7 polychlorinated biphenyls, 16 polycyclic aromatics hydrocarbons, 2 brominated diphenyl ethers, and 3 octyl/nonyl phenols and pentachlorobenzene. Most of these analytes are included in the list of priority substances in the framework on European Water Policy.Analyte extraction was performed by solid phase extraction using C₁₈ cartridges, and five isotopically labeled standards were added before extraction as surrogates. Analyses were performed by gas chromatography with tandem mass spectrometry (MS/MS) in electron impact mode. Accuracy and precision were evaluated by means of recovery experiments using water samples fortified at two concentration levels (25 and 250 ng L⁻¹), with satisfactory results for most of analytes. The excellent selectivity and sensitivity reached in selected reaction monitoring mode allowed us satisfactory quantification and confirmation at levels as low as 25 ng L⁻¹. Two MS/MS transitions were acquired for each analyte, using the Q/q intensity ratio as a confirmatory parameter. The method developed was applied to the analysis of surface, ground and wastewater samples collected from the Valencia Region (Spain).Analytical methodology using negative chemical ionization mode was also validated for the organochlorine compounds selected, showing a superior sensitivity and lower detection limits.     

固相萃取净化-气相色谱/串联质谱法测定茶叶中54种农药残留量

建立了固相萃取净化-气相色谱/串联质谱(SPE-GC-MS/MS)分析茶叶中54种农药残留的方法。样品用乙睛提取,提取液经石墨化炭黑/氨基固相萃取柱净化后,采用气相色谱-串联质谱方法在分时段选择反应监测模式下进行测定,外标法定量。当54种农药加标水平为10、50、100μg/kg时,回收率为60%～150%,方法的相对标准偏差小于16%;定量限(LOQ)均小于10μg/kg;在20～320μg/L范围内线性关系良好。方法已用于同时检测茶叶中农药多残留。     

捕集阱顶空气相色谱/质谱法测定水中的二氯一溴甲烷

建立了捕集阱顶空气相色谱/质谱测定水中二氯一溴甲烷的方法。采用正交实验设计对平衡温度、平衡时间、循环次数3个参数进行了优化,在平衡温度70 ℃、平衡时间20 min、循环次数2次的优化条件下,对水中的二氯一溴甲烷进行测定。结果显示,在0.1～10.0 μg/L范围内,二氯一溴甲烷的质量浓度和峰面积呈良好的线性关系,相关系数为0.9991。方法的检出限(S/N=3)为0.03 μg/L,定量限(S/N=10)为0.1 μg/L,回收率为83.1%～111.3%,相对标准偏差为1.7%～5.2%(n=6)。将该方法应用于水中二氯一溴甲烷的定性定量分析,效果良好。