SDE-GC-μEGD分析水中挥发性卤代烃

运用微滴溶剂萃取-气相色谱-微池电子捕获检测器联用技术(SDE-GC-μECD)对水中挥发性卤代烃(vHH)的分析进行了可行性探讨,优化了微滴溶剂萃取技术的多种影响因素.方法在0.1～20μg/L之间呈线性,相关系数为0.999 1～0.999 8,相对标准偏差在1.2%～4.6%之间,加标回收率在83%～117%之间.该方法所用的有机溶剂很少(1～2 μL),装置简便,是值得推广的绿色环保、高效的前处理方法.     

顶空气相色谱质谱法快速测定液体食品中的挥发性酸

建立了一种用于快速测定食品中挥发性有机酸的分析方法.利用顶空技术对样品进行前处理,并与气相色谱质谱联用,用离子选择对11种挥发性有机酸进行定量分析.在优化的实验条件下,方法线性关系良好,线性范围为0.20 ～5 mg/L.11种挥发性有机酸的相关系数均大于0.998 6,检出限为0.000 2 ～35.5 mg/L,比全扫描检出限低1 ～3个数量级.11种挥发性有机酸的回收率为93% ～99%,相对标准偏差均小于10%.该方法简便、快速、重复性好、定性定量准确,适于食品中挥发性有机化合物的检测.     

HS/GC-MS法对卷烟包装材料中挥发性有机化合物的检测

建立了一种用于测定卷烟包装材料中挥发性有机物(VOCs)的分析方法.采用三醋酸甘油酯为基质,利用顶空技术对样品进行前处理,并与气相色谱质谱(GC-MS)联用,用离子选择对17种挥发性有机物进行了定量分析.在优化的实验条件下,方法线性关系良好,17种挥发性有机物的相关系数均大于0.999,检出限为0.30 ～18 μg/m2,比全扫描的检出限低1 ～3个数量级.17种挥发性有机物的回收率为90% ～101%,相对标准偏差小于3.67%.该法简便、快速、重复性好、定性定量准确,适于大批卷烟包装材料中挥发性有机化合物的检测.     

顶空固相萃取/表面增强拉曼法对挥发性农药的快速检测研究

该文开发了一种基于金纳米膜的快速检测挥发性农药地虫磷和福美铁的方法。将通过氧化还原法在 不锈钢片表面制备的金纳米膜作为表面增强拉曼光谱（SERS）基底,结合顶空固相萃取法对挥发性农药地虫磷 和福美铁进行检测。地虫磷和福美铁分别在 75 ℃和 55 ℃顶空固相萃取 15 min得到显著的拉曼光谱信号,检 出限（LOD）均为5 × 10－3 mg/L;地虫磷（999 cm－1 ）和福美铁（1 381 cm－1 ）的特征峰拉曼光谱强度与农药质量浓 度在一定范围内呈线性关系,相关系数R2 分别为0. 984 8和0. 977 8。采用本法对果汁中的地虫磷和福美铁进 行检测,回收率分别为93. 3%～112%和92. 5%～104%,相对标准偏差分别为4. 1%～5. 2%和3. 4%～6. 5%。该 方法快速、灵敏,在挥发性农药检测方面具有潜在的应用价值。     

烟叶中26种挥发性与半挥发性有机酸的GC-MS/SIM法同时分析

采用加速溶剂萃取,以二氯甲烷-乙腈(体积比1 : 2)为萃取溶剂,N,O-双(三甲基硅基)三氟乙酰胺硅烷化,反-2-己烯酸和肉桂酸为内标,GC-MS/SIM法同时测定了烟叶中的甲酸、乙酸、乳酸、苯甲酸、十六酸、十八酸等26种挥发性、半挥发性有机酸.方法的回收率为81% ～106%,相对标准偏差为1.73% ～7.08%,检出限为0.1 ～13.72 μg/g.以该方法对部分烟叶样品中挥发性、半挥发性有机酸进行了定量分析.     

多孔膜萃取/微捕集方法及在线测定水中挥发性有机物

基于多孔膜萃取水中挥发性有机物和微捕集技术,构建了一套水中挥发性有机物(Volatile OrganicCompounds,VOCs)样品前处理装置,可自动、在线、连续完成水中挥发性有机物萃取、富集、热解析,传输给气相色谱分离检测。实验分别对膜萃取材料、萃取温度、萃取时间、吹扫气流速等进行了系统优化,并用于氯仿、1,2-二氯甲烷、四氯化碳、三氯乙烯、甲苯、四氯乙烯、乙苯、氯苯、苯乙烯9种挥发性有机物的检测。研究结果表明,采用膜萃取/微捕集装置,与气相色谱联用,在萃取温度60℃,萃取时间30 min,吹扫气流速8 mL/min条件下,采用氢焰离子化检测器(Flame ionization detector,FID),对氯代烃的检出限达到0.003～0.041μg/L,精确度为2.7%～13.0%,线性相关系数均大于0.9936,适用于在线检测水中挥发性有机物。     

CaO对煤中砷挥发性的抑制作用

在一定条件下CaO与As化合生成稳定的Ca3 (AsO4 ) 2 。模拟固定床燃烧试验 ,815℃下 ,CaO对煤中砷挥发性的抑制率范围在 3 0 5 %～ 37 35 % ,平均为 15 31% ,抑制效果明显。又进行了循环流化床燃烧试验 ,加入CaO后 ,砷在不同粒级流化床灰中的配置明显发生变化。细粒飞灰中砷含量明显降低 ,<0 0 30 8mm飞灰中砷含量从 172 8mg kg-1降至 17 6 7mg kg-1。烟道灰中砷含量降低 4～ 5 4倍以上。说明在煤燃烧过程中 ,一定温度条件下 ,CaO不仅可以固硫 ,而且对砷的挥发性也有明显的抑制作用。     

吹扫捕集和GC-MS测定水中26种挥发性有机物

用吹扫捕集和气相色谱―质谱联用技术对地表水中的26种挥发性有机污染物进行同时测定。实验结果在2.0～50.0μg/L范围内线性良好,相关系数均大于0.99,检出限在0.08～0.91μg/L范围内。方法的平均回收率为87.33%～116.68%,相对标准偏差(RSD)均小于5%。该方法前处理简单快速,采用内标法定量准确度高,重复性好,适用于清洁水中挥发性有机物的测定。     

固相萃取净化-气相色谱-质谱法测定记号笔油墨中8种挥发性苯系物的含量

称取记号笔笔芯中油墨0.200 0g,加入乙酸乙酯至体积为5.0mL,涡旋提取2min,将提取液流经HLB固相萃取柱进行净化处理。经净化的流出液用乙酸乙酯定容至10.0 mL,经0.22μm滤膜过滤,取滤液按仪器工作条件进行气相色谱-质谱法分析。选择HP-INNOWax毛细管色谱柱,在35～220℃之间按程序升温模式对8种挥发性苯系物(苯、甲苯、乙苯、对二甲苯、间二甲苯、异丙苯、邻二甲苯和苯乙烯)进行分离,并在电子轰击离子源(EI)和选择离子监测(SIM)模式下进行质谱测定。8种挥发性苯系物均在0.1～5.0mg·L~(-1)内与其相应的峰面积呈线性关系,其检出限(3S/N)为0.06～0.18mg·kg~(-1)。在阴性样品的基础上,在3个浓度水平上进行加标回收试验,测得8种化合物的回收率为79.8%～114%,测定值的相对标准偏差(n=5)为0.20～11%。应用此方法分析了116支记号笔中不同颜色的油墨样品,苯系物的检出率为76.9%,其质量分数为0.33～3.49×10~4 mg·kg~(-1)。     

冠心苏合丸中挥发性组分的分析及主成分冰片的测定

采用同时蒸馏-萃取法提取冠心苏合丸中的挥发性组分,测得两种冠心苏合丸中的挥发性组分含量分别为14％和9．8％。利用GC-MS方法对两种冠心苏合丸所得的挥发性组分进行分析,通过检索NIST98谱图库,并结合标准谱图库和有关文献,从冠心苏合丸的挥发性组分中分别确定出14、19种化学成分,分别占挥发性组分总检出量的97．24％和98．76％。用峰面积归一化法,得出各化学成分在挥发性组分中的相对百分含量。主要挥发性组分是冰片。并采用气相色谱法对冠心苏合丸中冰片的含量进行了测定冰片质量浓度在1．0～5、0mg／mL范围内成良好的线性关系,冰片的平均回收率为98％～106％。     

Simple analysis of naphthalene, fluorene, and anthracene in whole blood by gas chromatography/mass spectrometry after headspace-solid phase microextraction

A simple and sensitive method for the simultaneous analysis of naphthalene, fluorene, and anthracene in whole blood was developed using headspace-solid-phase microextraction (SPME) and GC/MS. A 0.5 g whole blood sample, 5 microL naphthalene, fluorene, and anthracene (50 microg/mL) as spiked standards, and 0.5 mL sodium hydroxide were placed into a 12 mL vial and sealed rapidly. The vial was immediately heated to 70 degrees C in an aluminium block heater, the needle of the SPME device was inserted through the septum of the vial, and the extraction fiber was exposed to the headspace for 15 min. Afterwards, the compounds extracted by the fiber were desorbed simultaneously by exposing the fiber in the gas chromatograph injection port. No interferences were found, and the time for analysis was about 30 min for one sample. This method was applied to a suicide case in which the victim ingested naphthalene, fluorene, and anthracene.     

干洗织物中氯代烃溶剂残留的气相-质谱测定

 采用固相微萃取和气 质联用技术(GC MS)对干洗衣物中氯代烯烃的残留和释放进行了分析测定。干洗过程使用的有害物质包括四氯乙烯(PCE)、三氯乙烯(TCE)及少量的三氯乙烷,这些挥发性有机物已列入许多国家和地区优先控制的污染物指标。该方法参照欧洲生态纺织品标准100对目标化合物的限量控制,以加标的标准贴衬为样品基质,将样品浸渍在含5%(体积分数)甲醇的饱和NaCl溶液中,于(40±1)℃水浴中超声处理10min后,再将样液用100μmPDMS固相微萃取纤维顶空提取,然后进行GC MS测定。     

Automated headspace solid-phase microextraction and in-matrix derivatization for the determination of amphetamine-related drugs in human urine by gas chromatography-mass spectrometry

An automated extraction and determination method for the gas chromatography (GC)-mass spectrometry (MS) analysis of amphetamine-related drugs in human urine is developed using headspace solid-phase microextraction (SPME) and in-matrix derivatization. A urine sample (0.5 mL, potassium carbonate (5 M, 1.0 mL), sodium chloride (0.5 g), and ethylchloroformate (20 microL) are put in a sample vial. Amphetamine-related drugs are converted to ethylformate derivatives (carbamates) in the vial because amphetamine-related drugs in urine are quickly reacted with ethylchloroformate. An SPME fiber is then exposed at 80 degrees C for 15 min in the headspace of the vial. The extracted derivatives to the fiber are desorbed by exposing the fiber in the injection port of a GC-MS. The calibration curves show linearity in the range of 1.0 to 1000 ng/mL for methamphetamine, fenfluramine, and methylenedioxymethamphetamine; 2.0 to 1000 ng/mL for amphetamine and phentermine; 5.0 to 1000 ng/mL for methylenedioxyamphetamine; 10 to 1000 ng/mL for phenethylamine; and 50 to 1000 ng/mL for 4-bromo-2,5-dimethoxyphenethylamine in urine. No interferences are found, and the time for analysis is 30 min for one sample. Furthermore, this proposed method is applied to some clinical and medico-legal cases by taking methamphetamine. Methamphetamine and its metabolite amphetamine are detected in the urine samples collected from the patients involved in the clinical cases. Methamphetamine, amphetamine, and phenethylamine are detected in the urine sample collected from the victim of a medico-legal case.     

Detection of ethanol in human body fluids by headspace solid-phase micro extraction (SPME)/capillary gas chromatography

Summary Ethanol has been found extractable from human whole blood and urine samples by headspace solid-phase micro extraction (SPME) with a Carbowax/divinylbenzene-coated fiber. After heating a vial containing the body fluid sample with ethanol, and isobutanol as internal standard (IS) at 70°C in the presence of (NH₄)₂SO₄, a Carbowax/divinylbenzene-coated SPME fiber was exposed in the headspace of the vial to allow adsorption of the compounds. The fiber needle was then injected into a middle-bore capillary gas chromatography (GC) port. The headspace SPME-GC gave intense peaks for both compounds; a small amount of background noises appeared, but did not interfere with the detection of the compounds. Recoveries of ethanol and IS were 0.049 and 0.026% for whole blood, respectively, and 0.054 and 0.085% for urine, respectively. The calibration curves for ethanol showed excellent linearity in the range of 80–5000 mg L^–1 for whole blood and 40–5000 mg L^–1 for urine; the detection limits for both samples were 20 and 10 mg L^–1, respectively. The data on actual determination of ethanol after the drinking of beer are also presented for two subjects.     

One step and highly sensitive headspace solid-phase microextraction sample preparation approach for the analysis of methamphetamine and amphetamine in human urine

A fiber-stable, repeatable and highly sensitive headspace solid-phase microextraction (HS-SPME) method was developed for the analysis of methamphetamine (MA) and amphetamine (AM) in urine using gas chromatography-mass spectrometry (GC-MS) in the selected ion monitoring mode. For sample preparation, the test specimen was placed in a 7 ml vial along with the additives (KOH and NaCl) and the internal standards (d8-MA and d8-AM), a glass insert containing heptafluorobutyric anhydride (HFBA) and heptafluorobutyric chloride (HFBCl) as derivatizing reagents was inserted into the vial, the vial was then sealed tightly. A SPME device with a 100 microm polydimethylsiloxane fiber was inserted into the vial and the fiber was exposed to the headspace in the insert, then the vial was heated and stirred at 100 degrees C and 600 rpm for 20 min for evaporation/adsorption/derivatization. The vaporized analytes (AM and MA) in the vial diffused into the glass insert though the holes on the insert, they absorbed onto the fiber, and then interacted with the vapor of the derivatizing reagent. Some of the analytes in the headspace of the glass insert may react with the vapor of the derivatizing reagent first, and then adsorb onto the fiber. The needle was finally removed and inserted into the injection port to desorb the analytes with the fiber exposed to the liner of the GC-MS system for analysis. By combining HFBCl and HFBA as derivatizing reagents and placing them in an insert, the HS-SPME method achieves high sensitivity for the analysis of AM and MA. Correlation coefficients derived from typical calibration curves in the 1.0-1700 ng ml(-1) range are 0.998 for MA and 0.994 for AM. The limits of detection and the limits of quantitation using a sample size of 1 ml are 0.3 and 1.0 ng ml(-1), respectively, for both MA and AM in urine specimens. Because the water hydrolysis of derivatizing reagent is much faster than the acylation reaction of the primary and secondary amines with the derivatizing reagent, the amphetamines cannot be acylated effectively over heated aqueous solution, and therefore this study provides a new acylation design in moisture surroundings. The proposed process also simplifies the procedure for urine sample preparation, and makes the automation of SPME possible.     

固相微萃取-气相色谱/质谱分析栀子花的头香成分

 分别用固相微萃取和动态顶空法分离栀子鲜花的头香成分,用GC/MS技术分析鉴定,并用GC/MS总离子流色谱峰的峰面积进行归一化定量。在固相微萃取方法中,共鉴定了54种化学成分,占总峰面积的99.98%。主要成分(质量分数)依次为金合欢烯（64.86%）、罗勒烯（29.33%）、芳樟醇（2.74%）、惕各酸顺式叶醇酯（1.34%）和苯甲酸甲酯（0.25%）等。经与动态顶空法的分析结果比较发现,固相微萃取法不仅操作简便,而且具有较高的采样灵敏度,获得的化学成分的信息量多于动态顶空法。     

Rapid determination of volatile constituents of Michelia alba flowers by gas chromatography-mass spectrometry with solid-phase microextraction

The volatile constituents of Michelia alba flowers, including fresh flowers, frozen flowers and withered flowers, were investigated by GC-MS. The volatiles in a simulated natural environment were sampled by solid-phase microextraction (SPME), with a 100 microm polydimethylsiloxane fiber at 25+/-5 degrees C for 4 h. The fibers were desorbed in a GC injection liner at 250 degrees C for 3 min. With headspace SPME-GC-MS analysis, 61 peaks were separated. The main compounds in headspace of fresh Michelia alba flowers included alpha-myrcene, (S)-limonene, (R)-fenchone, linalool, camphor, caryophyllene, germacrene D, etc., a greater number of compounds than for frozen flowers and withered flowers. At the same time, the biomarkers of fresh flowers were compared with the frozen flowers and withered flowers. In this study, headspace SPME-GC-MS afforded a simple and more sensitive sampling method for fresh Michelia alba flowers and other fresh flowers.     

Simple and sensitive analysis of nereistoxin and its metabolites in human serum using headspace solid-phase microextraction and gas chromatography-mass spectrometry

A simple method for the analysis of nereistoxin and its metabolites in human serum using headspace solid-phase microextraction (SPME) and gas chromatography-mass spectrometry (GC-MS) is developed. A vial containing a serum sample, 5M sodium hydroxide, and benzylacetone (internal standard) is heated to 70 degrees C, and an SPME fiber is exposed for 30 min in the headspace of the vial. The compounds extracted by the fiber are desorbed by exposing the fiber in the injection port of the GC-MS. The calibration curves show linearity in the range of 0.05-5.0 micrograms/mL for nereistoxin and N-methyl-N-(2-methylthio-1-methylthiomethyl)ethylamine, 0.01-5.0 micrograms/mL for S,S'-dimethyl dihydronereistoxin, and 0.5-10 micrograms/mL for 2-methylthio-1-methylthiomethylethylamine in serum. No interferences are found, and the analysis time is 50 min for one sample. In addition, this proposed method is applied to a patient who attempted suicide by ingesting Padan 4R, a herbicide. Padan 4R contains 4% cartap hydrochloride, which is an analogue of nereistoxin. Nereistoxin and its metabolites are detected in the serum samples collected from the patient during hospitalization. The concentration ranges of nereistoxin in the serum are 0.09-2.69 micrograms/mL.     

In Vitro and In Vivo Human Body Odor Analysis Method Using GO:PANI/ZNRs/ZIF−8 Adsorbent Followed by GC/MS

Among various volatile organic compounds (VOCs) emitted from human skin, trans-2-nonenal, benzothiazole, hexyl salicylate, α-hexyl cinnamaldehyde, and isopropyl palmitate are key indicators associated with the degrees of aging. In our study, extraction and determination methods of human body odor are newly developed using headspace-in needle microextraction (HS-INME). The adsorbent was synthesized with graphene oxide:polyaniline/zinc nanorods/zeolitic imidazolate framework-8 (GO:PANI/ZNRs/ZIF−8). Then, a wire coated with the adsorbent was placed into the adsorption kit to be directly exposed to human skin as in vivo sampling and inserted into the needle so that it was able to be desorbed at the GC injector. The adsorption kit was made in-house with a 3D printer. For the in vitro method, the wire coated with the adsorbent was inserted into the needle and exposed to the headspace of the vial. When a cotton T-shirt containing body odor was transferred to a vial, the headspace of the vial was saturated with body odor VOCs. After volatile organic compounds were adsorbed in the dynamic mode, the needle was transferred to the injector for analysis of the volatile organic compounds by gas chromatography/mass spectrometry (GC/MS). The conditions of adsorbent fabrication and extraction for body odor compounds were optimized by response surface methodology (RSM). In conclusion, it was able to synthesize GO:PANI/ZNRs/ZIF−8 at the optimal condition and applicable to both in vivo and in vitro methods for body odor VOCs analysis.     

Solid-phase Microextraction of Volatile Polar Compounds in Water

A method was developed for the analysis of volatile polar compounds in a water matrix using open cap vials Solid Phase Micro-Extraction (SPME) and Capillary Gas Chromatography (CGC). Both SPME techniques – direct sampling and headspace – were tested. Optimization of experimental conditions – exposure time, desorption time, with headspace SPME in addition the influence of the temperature and ionic strength of the sample solution on compound sorption, and finally GC response – were investigated. The analytes were extracted by directly immersing the 85 μm polyacrylate fiber in the aqueous sample or in the headspace. The linear range of the preconcentration process and the precision were examined. The amount of polar analytes sorbed on the fiber was determined and was found to be concentration dependent; it amounted to 0.014–0.64% in the concentration range of 0.00425–425 ppm studied in aqueous solution for direct sampling SPME and to 0.011–2.76% for solutions of concentration 0.0425–255 ppm for headspace SPME. The limits of determination were ascertained. Headspace SPME was applied to the analysis of real-life samples.