气相色谱法测定饮用水中二氯一溴甲烷和一氯二溴甲烷

建立液液萃取气相色谱法测定饮用水中二氯一溴甲烷和一氯二溴甲烷的方法。在200 m L水样中加入26g硫酸钠,以正己烷为萃取剂,用DB–5毛细管柱进行分离,以电子捕获检测器进行检测。二氯一溴甲烷和一氯二溴甲的质量浓度在0~50μg/L范围内与色谱峰面积均呈良好的线性,线性相关系数大于0.999,检出限均为0.01μg/L。水样加标回收率在92.4%~102.5%之间,测定结果的相对标准偏差均小于3%(n=7)。该方法操作简便,灵敏度高,适用于生活饮用水中二氯一溴甲烷和一氯二溴甲烷的测定。     

微囊藻毒素-LR阻抗型电化学免疫传感器的研究

基于1,6-己二硫醇自组装技术和纳米金吸附作用相结合的方法固定微囊藻毒素抗体,采用循环伏安法及交流阻抗法研究了该修饰电极的电化学性质,并优化了微囊藻毒素-LR(MC-LR)的测定条件.结果表明,在优化条件下,阻抗变化值与MC-LR标准品质量浓度分别在0.25 ～2.0 μg/L和2.0 ～95 μg/L 范围内呈良好的线性关系,其线性相关系数分别为0.994 4和0.997 2,检出限达0.085 μg/L(S/N=3);电极的重现性及稳定性较好,连续测定12次,相对标准偏差为7.8%;4 ℃下储存60 d后阻抗响应信号无明显变化;应用于饮用水中MC-LR的测定,样品的回收率为93% ～118%;检测时间为15 min.该传感器无需标记、灵敏度高、稳定性好,可用于快速检测饮用水源水中的MC-LR.     

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。     

自动顶空毛细管气相色谱法测定水中8种苯系物

建立自动顶空-毛细管气相色谱同时测定水中8种苯系物的方法.采用stabilwax-DA色谱柱,对平衡温度、平衡时间等顶空条件进行了优化,并对水中苯系物进行测定.8种苯系物平均加标回收率为93.3%～115.0%,检出限为1.2～2.0 μg/L,测定结果的相对标准偏差为1.8%～7.3%(n=6).该法操作简单、灵敏度高、重现性好,可以满足饮用水中苯系物的测定.     

气相色谱-负化学源质谱法测定船舶压载水中4种三卤甲烷北大核心CSCD

我国每年的船舶压载水排放量巨大,压载水中含有浮游生物、病原体及其幼虫或孢子等,若处理不当,会对排放水域的生态环境造成严重影响。排放压载水前常使用电解法对其进行处理,电解产生的次氯酸钠溶液,能有效杀灭残余的微生物。但电解后会产生副产物三卤甲烷(THMs),其对人体有一定的健康风险,建立船舶压载水中三卤甲烷的测定方法具有重要意义。该研究建立了采用气相色谱-负化学源质谱(GC-NCI-MS)测定船舶压载水中4种三卤甲烷(包括三氯甲烷、二氯一溴甲烷、一氯二溴甲烷、三溴甲烷)的分析方法。船舶压载水样品经过顶空进样技术处理后,通过DB-5MS UI毛细管色谱柱(30 m×0.25 mm×1.0μm)分离,气相色谱-负化学源质谱仪测定,在选择离子扫描(SIM)模式下分析,采用外标法进行定量。4种三卤甲烷在0.2~50μg/L范围内线性关系良好,相关系数(r)≥0.995,定量限(S/N=10)为0.1~0.2μg/L,在0.2、0.5、2.0μg/L 3个加标水平下,4种THMs的平均回收率为90.3%~106.8%,相对标准偏差(RSD)为1.4%~6.2%。该方法准确、稳定、可靠,可用于测定船舶压载水中4种THMs的含量。使用建立的测定方法对36个船舶压载水进行测定,三溴甲烷、二溴一氯甲烷、一溴二氯甲烷与三氯甲烷的检出率分别为83.3%、69.4%、22.2%和19.4%,检出值分别为34.25~221.5μg/L、3.52~41.87μg/L、1.52~8.56μg/L和0.02~5.46μg/L。     

气相色谱-串联质谱法测定土壤中的有机氯农药

建立了气相色谱-串联质谱测定土壤中有机氯农药的方法,同时测定了上海郊区的20个农业土壤。样品前处理包括加速溶剂萃取(弗罗里硅土池内净化)和凝胶渗透色谱净化在线浓缩。采用多反应监测模式的气相色谱-串联质谱分析有机氯农药,降低了背景干扰,提高了分析的灵敏度。在0.001～2 mg/L的质量浓度范围内,各种农药标准溶液的线性相关系数均大于0.995。分别向3种实际土壤样品中添加农药的混合标准溶液,所测定的有机氯农药的平均回收率为65.9%～140.0%,相对标准偏差为1.5%～20.3%(n=5)。有机氯农药的检出限（S/N=3）为0.1～3.0 μg/kg,定量限（S/N=10）为0.3～8.0 μg/kg。实际土壤样品的测定结果表明：六六六(1.82～3.70 μg/kg)和六氯苯(0.94～9.8 μg/kg)有少量检出,滴滴涕的检出率高达100%,其含量范围较宽(1.08～308.76 μg/kg),平均值为53.28 μg/kg,其中85%的样品中滴滴涕含量/(滴滴伊+滴滴滴)含量的比值小于1,表明滴滴涕主要来自于早期的使用     

超声萃取/气相色谱-质谱联用法对PVC制品中三(2-氯乙基)磷酸酯的快速测定

建立了PVC制品中三(2-氯乙基)磷酸酯(TCEP)的超声萃取/气相色谱-质谱联用快速测定分析方法.考察了萃取溶剂、萃取时间和水浴温度等因素对测定的影响.优化的超声萃取条件为以乙酸乙酯为萃取溶剂,萃取时间为60 min,水浴温度为40 ℃.在优化实验条件下,TCEP的质量浓度在0.1 ～10 mg/L范围内与峰面积呈良好的线性关系,相关系数为0.999 6,方法的定量下限(S/N=10)为0.1 mg/L,回收率为101% ～104%,相对标准偏差为0.76% ～3.5%.该方法具有线性范围宽、重复性好、准确度高、速度快等特点,可用于PVC制品中TCEP含量的测定.     

超高效液相色谱-串联质谱法同时检测环境水体中27种EDCs

应用超高效液相色谱-串联质谱法(UPLC-MS/MS)建立了环境水体中27种典型EDCs的分析方法。通过对固相萃取柱、淋洗液、流动相等的优化,确定以Oasis HLB固相萃取柱、二氯甲烷/丙酮(85:15,V/V)为淋洗液、0.1%氨水/乙腈(7:3,V/V)为流动相做水样预处理。在最优条件下,目标物在水中回收率约85.1%~119.8%,相对标准偏差(RSDs)在5.1%~11%,线性范围均在0.1~1000μg/L,各目标物标准品在UPLC-M S/M S系统中线性相关导致(R2)均大于0.997,检出限(S/N=3)为0.15~0.65μg/L,定量限(S/N=10)为0.20~0.81μg/L。该方法可适用于环境水中27种EDCs的同时检测。     

顶空气相色谱法同时测定树脂工艺品中7种残留苯系物

建立了顶空气相色谱(HS-GC)同时测定树脂工艺品中7种残留苯系物BTEX(苯、甲苯、乙苯、对二甲苯、间二甲苯、邻二甲苯、苯乙烯)的方法。对溶剂种类、萃取温度、萃取时间及HG-GC分离测定条件进行优化。结果表明,在顶空温度为130℃、平衡时间为60 min、粉碎样品粒径低于2 mm、选择DB-WAX色谱柱的条件下,可获得良好的分离效果和定量结果。7种残留苯系物在0.1～500μg范围内具有良好的线性关系(r2>0.999)。方法的定量下限(LOQ,S/N=10)在0.1～0.4μg.g-1之间,加标回收率为93%～114%,相对标准偏差(RSDs,n=6)为0.7%～4.8%。所建立的方法快速、准确,适用于树脂工艺品中苯系物的测定。     

分散液液微萃取-柱前衍生-高效液相色谱法测定水样中双酚A

建立了分散液液微萃取-柱前衍生-高效液相色谱法测定水样中双酚A的分析方法.通过交互正交试验和混合型优化实验设计对影响因素(萃取剂体积、分散剂类型及其体积、水样体积、pH值及离子强度)进行了优化.优化后的分散液液微萃取条件为:60 μL萃取剂,0.4 mL分散剂(甲醇),pH 4.0;优化后的柱前衍生化条件:0.1 mL 2.0 g/L衍生剂(对硝基苯甲酰氯)、衍生化时间30 min;方法的线性范围:0.002～0.2 mg/L(r=0.9997),检出限0.007 μg/L(S/N=3);不同浓度双酚A的萃取率为59.0%～63.0%,相对标准偏差(RSD)2.5%～9.2%(n=5);水样中双酚A的加标率为86.5%～107.1%,RSD为4.0%～11.9%(n=5),其它雌激素(雌酮、雌二醇、雌三醇和17α-乙炔基雌二醇)对双酚A的测定无干扰.本方法可以对水环境中的痕量BPA进行检测,具有操作简便、快速等优点.     

Multivariate optimization of a solid phase microextraction-headspace procedure for the determination of benzene, toluene, ethylbenzene and xylenes in effluent samples from a waste treatment plant

A method based on solid-phase microextraction (SPME) and gas chromatography with flame ionization detection (GC-FID) has been optimized for the determination of benzene, toluene, ethylbenzene and xylenes (BTEX) in water released from a waste treatment plant. The extraction step was optimized using fractional factorial and central composite designs including the following experimental factors: saline concentration; extraction time; desorption time; agitation velocity; headspace volume. A multiple function was used to describe the experimental conditions for simultaneous extraction of the compounds. The procedure, based on direct SPME at 50 degrees C, using a polydimethylsiloxane fiber, showed good linearity (r>0.997 over a concentration range 2-200 microg L(-1)) and repeatability (relative standard deviation (RSD)<4.23%) for all compounds, with limits of detection ranging from 0.05 to 0.28 microg L(-1), and limits of quantification ranging from 0.14 to 0.84 microg L(-1). Concentrations of the target compounds in these samples were between 145.8 and 1891 microg L(-1).     

Determination of phenols in landfill leachate-contaminated groundwaters by solid-phase extraction

A solid-phase extraction method for phenols in landfill leachates was developed and optimized in order to solve the expected and observed problems associated with an anaerobic matrix containing high concentrations of salts and organic matter. Isolute ENV+ cartridges exhibited the best retention of phenols of the four sorbents examined, and was the only cartridge which a 1 L leachate sample could pass through. With the other cartridges, clogging made this impossible. The final method, which included 27 different phenols, gave detection limits of <0.1 microg/L (drinking water concentration limit for pesticides) for most phenols (25), and for 12 phenols <0.01 microg/L. Recovery rates (determined for four concentrations in the range 1-25 microg/L, two replicates of each) were in the range 79-104% (SD 1-12%), except for phenol (26+/-1.3%) and 2-methoxyphenol (62+/-4.2%). Up to 12 different phenols could be identified in leachates from three Danish landfills, ranging in concentration from 0.01 to 29 microg/L, which is at the lower end of the concentration range usually found for phenols in landfill leachates (sub-microg/L to mg/L).     

液相色谱-二极管阵列检测器/离子阱质谱法检测水中的5种微囊藻毒素

建立了一种液相色谱-二极管阵列检测器(LC-DAD)/离子阱质谱(IT MS)对水中5种微囊藻毒素(microcystins)的分析方法。水中的微囊藻毒素经固相萃取富集和净化,经LC分离后,采用DAD和IT MS定性分析,DAD定量分析。在优化的条件下,水中5种微囊藻毒素的检出限为0.1 μg/L; 3个质量浓度加标水平(0.2、0.8和5 μg/L)的平均回收率为52.2%～115.2%,相对标准偏差为1.2%～10.0%。该方法从紫外吸收光谱和质谱角度同时进行定性定量分析,可用于地表水和饮用水中多种微囊藻毒素的检测。     

Determination of chlorophenols in water samples using simultaneous dispersive liquid-liquid microextraction and derivatization followed by gas chromatography-electron-capture detection

Simultaneous dispersive liquid-liquid microextraction (DLLME) and derivatization combined with gas chromatography-electron-capture detection (GC-ECD) was used to determine chlorophenols (CPs) in water sample. In this derivatization/extraction method, 500 microL acetone (disperser solvent) containing 10.0 microL chlorobenzene (extraction solvent) and 50 microL acetic anhydride (derivatization reagent) was rapidly injected by syringe in 5.00 mL aqueous sample containing CPs (analytes) and K(2)CO(3) (0.5%, w/v). Within a few seconds the analytes derivatized and extracted at the same time. After centrifugation, 0.50 microL of sedimented phase containing enriched analytes was determined by GC-ECD. Some effective parameters on derivatization and extraction, such as extraction and disperser solvent type and their volume, amount of derivatization reagent, derivatization and extraction time, salt addition and amount of K(2)CO(3) were studied and optimized. Under the optimum conditions, enrichment factors and recoveries are in the range of 287-906 and 28.7-90.6%, respectively. The calibration graphs are linear in the range of 0.02-400 microg L(-1) and limit of detections (LODs) are in the range of 0.010-2.0 microg L(-1). The relative standard deviations (RSDs, for 200 microg L(-1) of MCPs, 100 microg L(-1) of DCPs, 4.00 microg L(-1) of TCPs, 2.00 microg L(-1) of TeCPs and PCP in water) with and without using internal standard are in the range of 0.6-4.7% (n=7) and 1.7-7.1% (n=7), respectively. The relative recoveries of well, tap and river water samples which have been spiked with different levels of CPs are 91.6-104.7, 80.8-117.9 and 83.3-101.3%, respectively. The obtained results show that simultaneous DLLME and derivatization combined with GC-ECD is a fast simple method for the determination of CPs in water samples.     

Determination of selenium(IV) by catalytic stripping voltammetry with an in situ plated bismuth-film electrode.

A very sensitive and simple method is presented for the determination of Se(IV) by Osteryang square-wave cathodic stripping voltammery (OSWCSV). The method is based on the reduction of Se(IV) with Bi(III) onto an edge-plane type of pyrolytic graphite substrate, followed by a cathodic potential scan. OSWCSV studies indicate that the reduced selenium produced a distinct catalytic hydrogen wave at -1150 mV vs. Ag/AgCl. The peak height of the catalytic hydrogen wave was directly proportional to the initial Se(IV) concentration in the ranges of 0.1 - 1.0 and 1.0 - 20.0 microg L(-1) (correlation coefficients 0.9800 and 0.9901, respectively) when the optimized parameters were used. A 3sigma detection limit of 0.025 microg L(-1)0 Se(IV) was obtained at 30 s deposition time. The relative standard deviation was 4.0% on replicate runs (n = 12) for the determinations of 0.10 microg L(-1) Se(IV). Analytical results of natural water samples demonstrate that the proposed method is applicable to speciation analysis of Se(IV) and Se(VI).     

基于轻质萃取剂的溶剂去乳化分散液-液微萃取-气相色谱法测定水样中多环芳烃

以密度小于水的轻质溶剂为萃取剂,建立了无需离心步骤的溶剂去乳化分散液-液微萃取-气相色谱(SD-DLLME-GC)测定水样中多环芳烃的新方法。传统分散液-液微萃取技术一般采用密度大于水的有机溶剂为萃取剂,并需要通过离心步骤促进分相。而本方法以密度比水小的轻质溶剂甲苯为萃取剂,将其与丙酮(分散剂)混合并快速注入水样,获得雾化体系;然后注入乙腈作为去乳化剂,破坏该雾化体系,无需离心,溶液立即澄清、分相;取上层有机相(甲苯)进行GC分析。考察了萃取剂、分散剂、去乳化剂的种类及其体积等因素对萃取率的影响。以40 μL甲苯为萃取剂,500 μL丙酮为分散剂,800 μL乙腈为去乳化剂,方法在20～500 μg/L范围内呈现出良好的线性(r2=0.9942～0.9999),多环芳烃的检出限(S/N=3)为0.52～5.11 μg/L。用所建立的方法平行测定5份质量浓度为40 μg/L的多环芳烃标准水样,其含量的相对标准偏差为2.2%～13.6%。本法已成功用于实际水样中多环芳烃的分析,并测得其加标回收率为80.2%～115.1%。     

固相萃取-超高效液相色谱-电喷雾串联质谱法同时测定地表水中9种微囊藻毒素

建立了固相萃取-超高效液相色谱-电喷雾串联三重四极杆质谱(SPE-UPLC-ESI-MS/MS)联用技术分析水中9种微囊藻毒素的方法。样品经SPE提取和净化后,以Waters ACQUITY UPLCTM BEH C18色谱柱为分离柱,以含0.1%甲酸乙腈和含0.1%甲酸水作为流动相进行梯度洗脱,电喷雾离子源电离、正离子多反应监测模式质谱进行定性和定量分析。9种微囊藻毒素在0.1～50 μg/L或0.5～100 μg/L质量浓度范围内线性良好,相关系数为0.9990～0.9998,方法的检出限(以3倍信噪比计)为0.1～0.5 ng/L;高、中、低3个添加水平的回收率为75.8%～109%,相对标准偏差为0.49%～10.0%。结果表明,该方法灵敏、准确,检测范围广,分析速度快。应用该方法检测了杭州市两处水库水样中的微囊藻毒素,分别检出了3种和8种微囊藻毒素。     

On-line preconcentration with different solid adsorbents for lead determination

An on-line column preconcentration method based on the combined use of ammonium O,O-diethyldithiophosphate and activated carbon or polyurethane foam as adsorbents has been developed for the determination of Pb in water samples. The complexed Pb was eluted with ethanol and determined by flame atomic absorption spectrometry. The optimum preconcentration conditions are given for each adsorbent. The enrichment factors were 63 and 294, and the detection limits (3sigma) 3 microg L(-1) and 0.8 microg L(-1), respectively, for the carbon and foam systems. When the optimized procedures were applied to the determination of Pb in water samples the recovery efficiency was > 96%.     

Hydride generation for the direct determination of trace and ultra-trace level of arsenic and antimony in waters using derivative atomic absorption spectrometry

A new method is developed for the direct determination of trace and ultra-trace level of arsenic and antimony in waters by hydride generation derivative atomic absorption spectrometry (DHGAAS). The signal model and fundamentals of DHGAAS are described. The effects of atomization temperature, argon flow rate, acidity and concentration of KBH(4)and KI were investigated and analytical conditions were optimized. The sensitivities for arsenic and antimony were increased 36.4 and 27.6 times better than those of conventional hydride generation atomic absorption spectrometry (HGAAS). For a 2 mV min(-1) sensitivity range setting, the characteristic concentration was 0.003 microg L(-1) for arsenic and 0.004 microg L(-1)for antimony, and the detection limits (3sigma) were 0.015 micro g L(-1) for arsenic and 0.020 microg L(-1) for antimony. The proposed method was applied to the determination of arsenic and antimony in several water samples with satisfactory results.