一滴溶剂微萃取-毛细管气相色谱法分析水中的七种硝基苯类化合物

用一滴溶剂微萃取(SDME)-毛细管气相色谱联用技术测定水中的硝基苯、硝基甲苯类和硝基氯苯类化合物,对影响萃取的因素如萃取溶剂种类、液滴体积、搅拌速度、针尖入水深度、水样体积、萃取时间、萃取温度等进行了优化,结果表明:硝基苯和硝基甲苯类化合物在0.8～32 μg/L 范围内,硝基氯苯类化合物在0.04～3.2 μg/L 范围内均呈现良好的线性(r2>0.999),检出限可达0.01～0.3 μg/L。自来水加标样品测定的相对标准偏差和平均回收率(n=5)范围分别为3.1%～7.9%和101%～105%,废水加标样品测定的相对标准偏差和平均回收率(n=5)范围分别为3.3%～7.9%和92.5%～97.0%。优化后的SDME具有环保、灵敏、快速、简便等特点,适用于萃取水中的痕量硝基苯、硝基甲苯类和硝基氯苯类化合物。     

2，4-二硝基苯肼比色法快速测定餐饮企业油烟中醛酮类化合物含量的研究

基于醛酮类化合物中的羰基与2,4-二硝基苯肼在加热及酸的催化条件下生成黄色的苯腙类化合物,该化合物在强碱性条件下进一步生成红色或酒红色的显色物质,该文建立了一种2,4-二硝基苯肼比色法快速测定醛酮类化合物的方法,并将其应用于实际餐饮体系。最佳实验条件为：反应温度60 ℃,反应时间30 min,浓盐酸45 μL,醛肼比为1∶50,60 g/L KOH 2.0 mL。该方法操作简单,样品通量大,线性范围宽（2.5～15 μmol/L）,用于实际餐饮油烟样品的分析,加标回收率为80.0%～84.0%,相对标准偏差（RSD）均小于5%。该方法为快速、高效测量餐饮油烟中高浓度的醛酮类化合物提供了参考。     

固态萃取搅拌棒技术/气相色谱联用分析废水中的痕量爆炸物

制备了以聚醚砜酮(PPESK)为萃取相的新型固态萃取搅拌棒, 建立了一种固态萃取搅拌棒/热解吸器直接热解吸/气相色谱联用分析水样品中痕量爆炸物的新方法. 将萃取搅拌棒放入水样品中完成萃取后, 再直接放入热解吸器中于250 ℃热解吸, 将萃取到搅拌棒上的分析物一次性全部导入气相色谱柱中. 对于硝基苯类爆炸物, PPESK固态萃取搅拌棒的萃取容量比萃取纤维针提高1个数量级以上; 其萃取效率比PDMS固态萃取搅拌棒高2个数量级. 对所测定的7种爆炸物的最低检出限为0.008~0.022 μg/L, 方法的重复性误差(RSD)为6.9%~16%, 在线性浓度范围0.06~10.0 μg/L(除TNT)内, 线性相关系数r为0.9962~0.9998. 在优化的条件下对硝基苯类炸药生产过程中产生的废水进行了分析, 结果表明, 方法的回收率分别为88%~100%(低浓度样品)和61%~88%(高浓度样品), 该方法的重复性误差(RSD)小于11%.     

固相萃取-电感耦合等离子体质谱（ICP-MS）法测定海水中6种金属元素

为了实现海水中金属元素的绿色分离和快速检测,建立了新型螯合树脂为填料,固相萃取-电感耦合等离子体质谱（ICP-MS）测定海水中6种金属元素含量的方法。海水中Cu,Pb,Co,Ni,Cr,Mo金属离子与亚氨基二乙酸型螯合树脂形成螯合物,经固相萃取、洗脱,实现金属离子从海水中定量分离富集。在最佳实验条件下,测得方法的相对标准偏差（RSD）为1.7 %～3.6 % ,加标回收率为82.6 %～102 %,检出限为0.03 μg /L～0.15 μg /L。本研究采用亚氨基二乙酸型螯合树脂为填料的固相萃取,实现了海水分析的绿色样品前处理方法,与ICP-MS相结合用于海水标准样品和实际样品的分析,获得了满意的结果。     

ACF-SPME检测海洋水体中的多环芳烃

使用新型活性炭纤维(ACF)作为固相微萃取(SPME)技术的萃取纤维,检测了海水中的多环芳烃。得到ACF-SPME萃取多环芳烃的最优条件为:在搅拌条件下,盐浓度10%,pH3,温度60℃水浴中直接萃取40min。并确定16种多环芳烃的RSD(n=5)为1.8%～10%、线性范围为0.1～500μg/L、检出限为0.1～100μg/L。对东海近海海水进行了分析,结果表明海水中PAHs浓度在检测限以下,同时进行加标回收实验,得到16种多环芳烃的回收率在80%～128%。     

固相微萃取气相色谱法测定水产品中五氯苯酚及其钠盐残留量

采用自动固相微萃取(Automated SPME)超声波辅助萃取技术(UE)与气相色谱联用测定水产品中五氯苯酚及其钠盐残留量.实验优化了SPME直接萃取技术,样品调pH 2,超声波40℃萃取30 min后,用85μm聚丙烯酸酯(PA)萃取头90℃自动搅拌萃取30 min,270℃解吸5 min.最低检出量为0.01μg/kg;五氯苯酚线性范围0.001～10 μg/L,r=0.9999;对鳕鱼加标五氯苯酚1.0、5.0μg/kg回收率分别为71.0%～80.0%、77.2%～91.4%,相对标准偏差(RSD)为6.3%和8.6%(n=3).该方法简便、灵敏、稳定,无溶剂污染,是测定水产品中五氯苯酚及其钠盐残留量的理想方法.     

高效液相色谱-串联质谱法同时测定红小豆中残留的6种咪唑啉酮类除草剂

建立了同时测定红小豆中6种咪唑啉酮类除草剂残留的高效液相色谱-串联质谱分析方法。样品经0.1 mol/L NH4HCO3(pH 5)-甲醇(体积比为70∶30)溶液提取,二氯甲烷液-液萃取和凝胶渗透色谱净化后,采用Inertsil ODS-3色谱柱(2.1 mm×150 mm, 5 μm)分离,以甲醇-0.1%乙酸为流动相梯度洗脱,离子阱质谱在选择离子模式下测定。咪唑啉酮类除草剂在10～200 μg/L(灭草喹在5～100 μg/L)内线性关系良好,相关系数为0.9987～0.9997;方法的检出限为0.2～0.5 μg/kg;在红小豆中3个加标水平的平均加标回收率为81.6%～99.4%,相对标准偏差为3.1%～7.8%。该方法简便、灵敏度高、精密度好,适用于红小豆中多种咪唑啉酮类除草剂残留的测定。     

活性炭固相微萃取-气相色谱联用测定海水中酞酸酯

利用自制的活性炭纤维结合固相微萃取-气相色谱联用技术(ACF-SPME-GC)分析了海水中4种邻苯二甲酸酯.对萃取温度、离子强度、吸附和热解吸时间等影响因素进行了研究.结果表明,在盐浓度为15%和萃取温度为60 ℃条件下萃取60 min,效果最好.在最优化条件下,本方法的线性范围为0.1～1000 μg/L; 检出限为0.01～10 μg/L; 相对标准偏差均小于10%.将ACF-SPME-GC技术用于实际海水样品的分析,未检测出这4种邻苯二甲酸酯化合物.     

固相微萃取-气相色谱法测定白洋淀水样中的邻苯二甲酸酯类化合物

建立了固相微萃取(SPME)-气相色谱法(GC)分析环境水样中痕量邻苯二甲酸酯类化合物(PAEs)的方法。选用100 μm聚二甲基硅烷(PDMS)萃取纤维,在磁力搅拌条件下,对水样中的PAEs萃取富集60 min,然后直接注入GC进样口,在250 ℃温度下解吸4 min后进行分析测定,13种PAEs能得到充分提取和分离。方法的重现性(以相对标准偏差(RSD)计为0.2%～9.7%,检出限为0.02～0.83 μg/L。将本方法应用于白洋淀水样中PAEs的分析检测发现,样品中邻苯二甲酸二异丁酯(DIBP)、邻苯二甲酸二丁酯(DBP)、邻苯二甲酸二(2-乙基己基)酯(DEHP)检出率相对较高。对水样进行两个浓度水平(2.5 μg/L和5.0 μg/L)的加标试验,加标回收率为75.3%～111.0%,RSD为2.1%～8.0%(n=3),能够满足环境水样中痕量PAEs的测定要求。     

单滴液相微萃取气相色谱测定水中的酞酸酯类化合物

采用单滴液相微萃取与气相色谱测定水中的酞酸二甲酯(DMP)和酞酸二丁酯(DBP).考察了萃取溶剂、萃取时间及搅拌速度等因素对萃取结果的影响,确定最佳萃取条件为:3 mL水样放置于4 mL样品瓶中,以600 r/min速度进行磁力搅拌,萃取20 min.该方法对酞酸二甲酯和酞酸二丁酯的富集倍数为228和318,检出限为1.4和0.8 μg/L,相对标准偏差为9.4%和6.4%.对地表水、污水和海水的加标回收率DMP在94.5%～99.3%,DBP在87.0%～102%之间.     

超声-气相联合扩散法快速合成ZIF-8用于硝基芳香化合物炸药的传感

三维微孔沸石咪唑基骨架(ZIF-8)纳米晶通过超声-气相联合扩散法快速合成.对该纳米晶进行荧光研究表明,纳米晶对硝基芳香化合物炸药具有良好的荧光淬灭能力.通过建立的Stern-Volmer方程,在1×10-4～8×10-4 mol/L范围内,每种炸药的浓度与纳米晶的荧光淬灭程度呈线性关系.对于2,4,6-三硝基苯酚(T...     

The determination of nitroaromatics and nitramines in ground and drinking water by wide-bore capillary gas chromatography

A method has been developed to determine the concentration of nitroaromatics and nitramines in drinking water at levels below those previously achieved by gas chromatography. The nitroaromatics and nitramines are extracted from water using toluene and isoamyl acetate, respectively. The extracts are analyzed via a gas chromatograph equipped with a DB-1301 widebore fused-silica capillary column and an electron capture detector. Method detection limits of 0.003 micrograms/L for 2,6-dinitrotoluene (2,6-DNT), 0.04 micrograms/L for 2,4-dinitrotoluene (2,4-DNT), 0.06 micrograms/L for 2,4,6-trinitrotoluene (TNT), 0.3 micrograms/L for cyclotrimethylenetrinitramine (RDX), and 6.0 micrograms/L for cyclotetramethylenetetranitramine (HMX) have been obtained using this method.     

Effects of Nitrobenzenes on DNA Damage in Germ Cells of Rats

IntroductionSince nitroaromatic compounds constitute a classof industrial chemicals that are present in China andprobably in many other industrialized countries as well,it is necessary to gain insight into their potential hazardto organisms.In recent year…     

Simultaneous determination of organic and cationic species in explosives residues with column-switching liquid chromatography-ion chromatography system

A new column-switching method has been proposed for the determination of 14 organic explosives (1,3,5,7-tetranitro-N-methylaniline, 1,3,5-trinitro-1,3,5-triazacyclohexane, 1,3,5-trinitrobenzene, 1,3-dinitrobenzene, nitrobenzene, 2,4,6-N-tetranitro-N-methylaniline, Trinitrotoluene, 4-amino-2,6-dinitrotoluene, 2-amino-4,6-dinitrotoluene, 2,6-dinitrotoluene, 2,4-dinitrotoluene, 2-nitrotoluene, 4-nitrotoluene, and 3-nitrotoluene) and/or five inorganic cations (Na(+), NH(4)(+), K(+), Mg(2+), and Ca(2+)) using liquid chromatography linked to ion chromatography by a switching valve. The mobile phase was methanol-water (40/60, v/v) for a C18 reversed-phase column and 3 mM of methanesulfonic acid (pH 2.5) for a cation-exchange column, respectively. Under the optimal conditions, the 14 organic explosives and the five inorganic cations were separated and detected simultaneously within 45 min. The limits of detection (S/N = 3) of the 14 organic explosives and the five inorganic cations were in the range of 0.0048-0.0333 mg/L and 0.0116-0.1851 mg/L, respectively. The linear correlation coefficients were 0.9971-0.9999, and the relative standard deviation of the retention time and the peak area were 0.02-0.31% and 0.51-3.64%, respectively. The method was successfully applied to the determination of organic explosives and inorganic cations in dust samples.     

Determination of nitroaromatic, nitramine, and nitrate ester explosives in soil by gas chromatography and an electron capture detector

Hazardous waste site characterization, forensic investigations, and land mine detection are scenarios where soils may be collected and analyzed for traces of nitroaromatic, nitramine, and nitrate ester explosives. These thermally labile analytes are traditionally determined by high-performance liquid chromatography (HPLC); however, commercially available deactivated injection port liners and wide-bore capillary columns have made routine analysis by gas chromatography (GC) possible. The electron-withdrawing nitro group common to each of these explosives makes the electron capture detector (ECD) suitable for determination of low concentrations of explosives in soil, water, and air. GC-ECD and HPLC-UV concentration estimates of explosives residues in field-contaminated soils from hazardous waste sites were compared, and correlation (r>0.97) was excellent between the two methods of analysis for each of the compounds most frequently detected: 2,4,6-trinitrotoluene (TNT), hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), 2,4-dinitrotoluene (2,4-DNT), 1,3-dinitrobenzene (1,3-DNB), 1,3,5-trinitrobenzene (TNB), and octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX). The analytes were extracted from soils with acetonitrile by 18 h of sonication in a cooled ultrasonic bath. Two soil-to-solvent ratios were evaluated: 2.00 g:10.00 ml and 25.0 g:50.0 ml. GC-ECD method detection limits were similar for the two soil-to-solvent ratios and were about 1 mug kg(-1) for the di- and trinitroaromatics, about 10 mug kg(-1) for the mono-nitroaromatics, 3 mug kg(-1) for RDX, 25 mug kg(-1) for HMX, and between 10 and 40 mug kg(-1) for the nitrate esters (nitroglycerine [NG] and pentaerythritol tetranitrate [PETN]). Spike recovery studies revealed artifacts introduced by the spiking procedure. Recoveries were low in some soils if the amount of soil spiked was large (25.0 g) compared to the volume of spike solution added (1.00 ml). Recoveries were close to 100% when 2.00-g soil samples were spiked with 1.00 ml of solution. Analytes most frequently found in soils collected near buried land mines were the microbial transformation products of TNT (2-amino-4,6-dinitrotoluene [2-Am-DNT] and 4-amino-2,6-dinitrotoluene [4-Am-DNT]), manufacturing impurities of TNT (2,4-DNT, 2,6-DNT, and 1,3-DNB), and TNT. The microbial reduction products of the isomers of DNT and of 1,3-DNB were also detected, but the ECD response to these compounds is poor.     

Metabolism of 2,4-dinitrotoluene and 2,6-dinitrotoluene, and their dinitrobenzyl alcohols and dinitrobenzaldehydes by Wistar and Sprague-Dawley rat liver microsomal and cytosol fractions

The metabolism of 2,4-dinitrotoluene (2,4-DNT), 2,4-dinitrobenzyl alcohol (2,4-DNB), 2,4-dinitrobenzaldehyde (2,4-DNBAl), 2,6-DNT, 2,6-DNB and 2,6-DNBAl in the microsomal and cytosol fractions prepared from unfortified male Wistar and male Sprague-Dawley (S.D.) rat livers was investigated. Data obtained by high-performance liquid chromatography (HPLC) indicated that the products of dinitrotoluenes (2,4-DNT and 2,6-DNT), dinitrobenzyl alcohols (2,4-DNB and 2,6-DNB), and dinitrobenzaldehydes (2,4-DNBAl and 2,6-DNBAl) in the microsomal and cytosol preparations containing nicotinamide adenine dinucleotide phosphate (NAD(P] and reduced NAD(P)(NAD(P)H) were dinitrobenzyl alcohols (2,4-DNB and 2,6-DNB), dinitrobenzaldehydes (2,4-DNBAl and 2,6-DNBAl), and dinitrobenzoic acids (2,4-DNBA and 2,6-DNBA), and dinitrobenzyl alcohols (2,4-DNB and 2,6-DNB), respectively. From these results, it was concluded that the dinitrobenzaldehydes (2,4-DNBAl and 2,6-DNBAl) were intermediates in the oxidations of dinitrobenzyl alchols (2,4-DNB and 2,6-DNB) to dinitrobenzoic acids (2,4-DNBA and 2,6-DNBA), and that the oxidations of dinitrobenzyl alcohols (2,4-DNB and 2,6-DNB) to dinitrobenzaldehydes (2,4-DNBAl and 2,6-DNBAl) and the reductions of dinitrobenzaldehydes to dinitrobenzyl alcohols (2,4-DNB and 2,6-DNB) were reversible.(ABSTRACT TRUNCATED AT 250 WORDS)     

分散液-液微萃取与气相色谱-质谱联用分析环境水样中痕量的2,4-二硝基甲苯和磷酸三(2-氯乙基)酯

建立了分散液-液微萃取与气相色谱-质谱联用同时测定环境水样中痕量2,4-二硝基甲苯和磷酸三(2-氯乙基)酯的新方法。对影响萃取效率的因素进行了详细的考察和优化,确定采用的最佳萃取条件为: 将0.8 mL乙醇和60 μL氯仿的混合溶液快速注入5.0 mL的样品溶液中,振动混匀120 s后,离心分离,吸取沉积在试管底部的氯仿相直接进样分析。该方法对磷酸三(2-氯乙基)酯和2,4-二硝基甲苯的检出限(信噪比为3)分别为0.01和0.04 μg/L,富集倍数分别为96.6和127.5;两种物质的线性范围达3到4个数量级;日内和日间测定的相对标准偏差(RSDs, n=6)分别为8.6%～11.5%和8.9%～12.0%。将该方法用于环境水样中2,4-二硝基甲苯和磷酸三(2-氯乙基)酯的分析,其加标回收率为102.1%～110.9%。方法具有操作简单、方便快速、灵敏度高、无交叉污染和环境友好等优点。     

Investigation of different alcoholic modifiers for the separation and determination of two isomers of dinitrotoluene (2,4 and 2,6) by ion mobility spectrometry

Some alcoholic modifier gases were applied to separate isomer peaks in ion mobility spectrometry (IMS). Different mechanisms have been investigated on the separation, such as collision cross-section and analyte-modifier cluster formation. In this regard, some parameters that affected the cluster formation, such as dipole moment, electron affinity, the position of functional groups, and the modifier structure, were evaluated. On the other hand, some effective experimental parameters, including cell temperature and the flow rates of the drift and modifier gases, were also optimized. The combination of dispersive liquid–liquid microextraction with thin-film evaporation (DLLME-TFE) was used as a sample preparation method for the extraction of 2,4-dinitrotoluene (2,4-DNT) and 2,6-dinitrotoluene (2,6-DNT) isomers (as the target analytes). Isobutanol was selected as the alcoholic modifier to separate the ion molecular peaks of these isomers. The limit of detection and the limit of quantification obtained were 15 and 50 μg L⁻¹, and the linear dynamic range (50–700 μg L⁻¹) with coefficient of determination of 0.9941 and 0.9914 were obtained for 2,4-DNT and 2,6-DNT, respectively. The intra- and inter-day relative standard deviations were obtained between 3% and 5%. For validation of the method, determination of the isomers was accomplished for a red wastewater field sample, resulting in relative recovery values of about 96%.     

Solvating gas chromatography with chemiluminescence detection of nitroglycerine and other explosives

A separation technique known as solvating gas chromatography (SGC), which utilizes packed capillary columns and neat carbon dioxide as mobile phase, was used for the separation of nitroglycerine (NG) and other nitrogen-containing explosives including 2,6-dinitrotoluene (2,6-DNT), 2,4-dinitrotolulene (2,4-DNT), 2,4,6-trinitrotoluene (2,4,6-TNT), and pentaerythritol tetranitrate (PETN). SGC was coupled for the first time to a selective chemiluminescence thermal energy analyzer (TEA) detector for nitro-functional group specificity and sensitive detection of these compounds. TEA calibration curve for NG showed linearity in the sub-microg ml(-1) range. Soil samples containing NG were used to test the validity of the technique. Detector response of SGC-TEA versus SGC-flame ionization detection for NG was also evaluated.     

Solid phase microextraction ion mobility spectrometer interface for explosive and taggant detection

Ion mobility spectrometry (IMS) is a rugged, inexpensive, sensitive, field portable technique for the detection of organic compounds. It is widely employed in ports of entry and by the military as a particle detector for explosives and drugs of abuse. Solid phase microextraction (SPME) is an effective extraction technique that has been successfully employed in the field for the pre-concentration of a variety of compounds. Many organic high explosives do not have a high enough vapor pressure for effective vapor sampling. However, these explosives and their commercial explosive mixtures have characteristic volatile components detectable in their headspace. In addition, taggants are added to explosives to aid in detection through headspace sampling. SPME can easily extract these compounds from the headspace for IMS vapor detection. An interface that couples SPME to IMS was constructed and evaluated for the detection of the following detection taggants: 2-nitrotoluene (2-NT), 4-nitrotoluene (4-NT), and 2,3-dimethyl-2,3-dinitrobutane (DMNB). The interface was also evaluated for the following common explosives: smokeless powder (nitrocellulose, NC), 2,4-dinitrotoluene (2,4-DNT), 2,6-dinitrotoluene (2,6-DNT), 2,4,6-trinitrotoluene (2,4,6-TNT), hexahydro-1,3,5-trinitro-s-triazine (RDX), and pentaerythritol tetranitrate (PETN). This is the first peer reviewed report of a SPME-IMS system that is shown to extract volatile constituent chemicals and detection taggants in explosives from a headspace for subsequent detection in a simple, rapid, sensitive, and inexpensive manner.