喷涂废水中邻苯二甲酸酯测定的优化研究

选取固相萃取GC-MS法定量检测喷涂废水中四种邻苯二甲酸酯类(PAEs),运用正交设计法,研究了pH、洗脱剂、洗脱体积、洗脱速率和水样流速对废水中PAEs回收率的影响。结果表明,pH为2.5时回收率最佳(均100%);在该pH下,洗脱剂对4种PAEs的回收率影响最大,水样流速次之,洗脱速率与洗脱体积对4种PAEs的回收率影响相对较小。样品前处理最优参数为:水样流速8mL/min、洗脱剂为乙酸乙酯、洗脱体积4mL、洗脱速率2mL/min;该条件下4种PAEs的线性范围为0.2～8.0μg/mL,相关系数均0.99,喷漆废水中平均加标回收率为61.1%～103%,相对标准偏差为3.1%～14.6%,均可满足试验要求。     

固相萃取—气相色谱法测定海水中的666、DDT

采用固相萃取技术富集海水中的666、DDT,并使用气相色谱进行测定。主要包括不同填料(C8、C18、C18-N)、SPE柱规格(500 mg/3 mL、500 mg/6 mL)、洗脱试剂、上样流速、水样pH和洗脱试剂体积6个因素对666、DDT富集效率的影响。最终确定最优条件为:采用500 mg/6 mL C18SPE小柱,调节海水pH=6,上样流速4~5mL/min,10 mL二氯甲烷洗脱。优化后的固相萃取-气相色谱方法测定海水中666、DDT加标10 ng/L回收率为75.7%~110.4%,精密度为1.16%~4.00%,方法检出限为0.19~1.20 ng/L。     

固相萃取法测定土茯苓中4种有机磷农药残留量

文章研究了固相萃取法测定土苻苓中4种有机磷农药(敌敌畏、乐果、甲基对硫磷、对硫磷)的可行性。对影响实验结果的提取剂、洗脱剂、洗脱剂用量进行了条件优化。在优化后的实验条件下,该方法除了对乐果的线性范围在3.55～20μg/mL之间,其余三种有机磷农药线性范围均在2.5～20μg/mL之间,相关系数R为0.9991～0.9997,回收率为79.0%～109%,相对标准偏差为6.7%～8.9%。检出限分别为:敌敌畏0.25μg/mL;乐果2.85μg/mL;甲基对硫磷0.20μg/mL;对硫磷0.15μg/mL。实验结果表明,该方法操作简便省时,灵敏准确,适用于多种有机磷农药的同时分析测定。     

固相萃取-气相色谱法测定水中的酚类污染物

研究了自制活性炭纤维小柱对水中四种痕量酚的固相萃取条件,选用乙醇作为洗脱剂,并采用气相色谱法进行检测。在实验条件下,即水样溶液pH=1,吸附流速为3mL/min,洗脱流速为0.1mL/min,四种酚的回收率在63%~102%之间,RSD在2%~9%之间,最低检测浓度达到 级。方法用于分析测定实际环境水样,结果令人满意。     

固相萃取-气相色谱质谱法测定水样中5种邻苯二甲酸酯研究

建立了采用固相萃取技术结合气相色谱质谱法对5种邻苯二甲酸酯(PAEs) 进行富集、检测的方法,并成功应用于实际水样分析.实验中采用加标回收率来评价萃取效率,考察并优化了影响萃取效率的主要因素,包括固相萃取小柱的种类、洗脱剂类型、洗脱次数和用量、样品环境影响等.结果表明:在最佳萃取条件下,该法对5种PAEs(邻苯二甲酸二甲酯、邻苯二甲酸二乙酯、邻苯二甲酸二丁酯、邻苯二甲酸丁基苄基酯和邻苯二甲酸(2-乙基己基)酯)具有较高的萃取效率;在浓度范围为0.50~10.0 mg/L时,线性相关系数为0.992 6~0.999 8;检出限为0.05~0.37μg/L,定量限为0.20~1.48μg/L,空白水样加标回收率范围为95%~115%,相对标准偏差为2.4%~11.1%.该方法操作简单、稳定性好、回收率高,可以用于测定实际水样中的PAEs类增塑剂.     

对水中有机磷农药样品保存方法的优化

优化了对水中11种有机磷农药检测的样品保存方法。加标水样在4℃下保存一定时间后,通过液液萃取,气相色谱-质谱（选择离子模式）法测定有机磷农药的回收率。在不加入稳定剂的情况下,水样的保存时间不宜超过16h。为延长样品的保存时间,向水样中加入有机溶剂和pH调节剂作为稳定剂。实验结果表明,当在1000ml样品中加入10ml正己烷和10mlpH=3．6的醋酸-醋酸钠缓冲溶液时,可以将样品保存时间延长至48h。为验证方法的有效性,以地表水作为实际水样,加标浓度水平在0．2μg／L和0．04μg／L时,48h后的平均加标回收率在76．2％-95．0％之间,RSD在2．4％-7．2％之间。     

固相萃取-液相色谱法测定土壤中酚类化合物

建立了索氏提取-固相萃取-液相色谱法测定土壤中环境优先监测的6种酚类污染物监测方法。利用索氏提取和固相萃取法提取净化了土壤中6种酚类化合物,比较5种固相萃取柱萃取的效果,选择PSD固相萃取柱,优化了固相萃取条件,影响固相萃取回收率的4种因子显著性顺序为:水样p H上样速度洗脱液体积溶剂类型。最佳固相萃取条件:上样的水样p H=3,上样速度5 m L/min,洗脱溶剂为乙腈,洗脱溶剂体积是10.0 m L。酚类化合物的检出限为0.01~0.05 mg/kg,加标回收率在85.39%~105.82%之间,相对标准偏差RSD10%(n=7),该法操作方便,灵敏度高,可用于土壤中多种酚类化合物的测定。     

自动固相萃取-气相色谱质谱法测定饮用水源地水中有机氯农药的研究

建立了自动固相萃取-气相色谱质谱仪测定饮用水源地水体中8种痕量有机氯农药的检测法.采用Supelclean ENVI-18固相萃取柱以10 mL/min流速富集500 mL水样,再依次用7.5 mL乙酸乙酯和10 mL二氯甲烷进行洗脱.8种物质在0.188 mg/L~2.04 mg/L范围内线性良好,相关系数均在0.997以上;检出限为0.011μg/L~0.034μg/L;实际水样加标回收率为82.9%~103%,相对标准偏差为0.7%~8.3%.该方法自动化程度高、检出限低、灵敏度高、结果准确,适用于饮用水源地水体中痕量有机氯农药的测定.     

FAAS法研究六钛酸钾晶须对Cd(Ⅱ)的动/静态吸附行为

以火焰原子吸收光谱法(FAAS)为检测手段,研究了六钛酸钾晶须对镉的动态、静态吸附性能,考察影响吸附率的相关因素,对比了静态、动态解吸回收率的影响,同时考察了解吸剂的酸度、流速、用量等对回收率的影响,结果表明:在动态实验中,pH7,流速1.0mL/min.,吸附剂用量0.1g时,Cd(Ⅱ)的吸附效果最佳;以10mL0.1mol/LHNO3为洗脱剂,流速为0.5mL/min时,可将Cd(Ⅱ)完全洗脱。静态实验中,pH7,六钛酸钾晶须用量0.2g,吸附率可达到90%以上。以25mL2mol/L的硝酸溶液对Cd(Ⅱ)进行洗脱,Cd(Ⅱ)的回收率可达99%以上。在优化的试验条件下,本法的检出限为12ng/mL;相对标准偏差为0.7%(Cd(Ⅱ):1μg/mL,n=11)。     

自动固相萃取-GC/MS测定水中多环芳烃和有机氯农药

采用自动固相萃取-气相色谱/质谱技术,建立了地表水中痕量多环芳烃和有机氯农药的检测方法。调节水样pH2,加入1%甲醇,使用C18固相萃取柱富集,3 mL丙酮+3 mL二氯甲烷洗脱后浓缩定容。采用气相色谱/质谱联用的全扫描模式进行分析,选择特征离子定量,方法检出限为0.026~8.772 ng/L。加标水平为0.1μg/L时,样品加标回收率在74.8%~109%之间,RSD为0.01%~14.5%。该方法自动化程度高、快速、准确、重复性好,能满足地表水体中持久性有机污染物分析的要求。     

TiO2 nanotubes as solid-phase extraction adsorbent for the determination of polycyclic aromatic hydrocarbons in environmental water samples

An analytical method based on TiO2 nanotubes solid-phase extraction (SPE) combined with gas chromatography (GC) was established for the analysis of seven polycyclic aromatic hydrocarbons (PAHs): acenaphtylene, acenaphthene, anthracene, fluorene, phenanthrene, fluoranthene and pyrene. Factors a ecting the extraction e ciency including the eluent type and its volume, adsorbent amount, sample volume, sample pH and sample flow rate were optimized. The characteristic data of analytical performance were determined to investigate the sensitivity and precision of the method. Under the optimized extraction conditions, the method showed good linearity in the range of 0.01–0.8 g/mL, repeatability of the extraction (RSD were between 6.7% and 13.5%, n = 5) and satisfactory detection limits (0.017–0.059 ng/mL). The developed method was successfully applied to the analysis of surface water (tap, river and dam) samples. The recoveries of PAHs spiked in environmental water samples ranged from 90% to 100%. All the results indicated the potential application of titanate nanotubes as solid-phase extraction adsorbents to pre-treat water samples.     

固相萃取和高效液相色谱联用测定污水中的五氯苯酚

采用固相萃取和高效液相色谱相结合的方法对污水中五氯苯酚的含量进行定量检测。结果表明,污水的pH值为4,流速控制在4mL/L以内,C18固相萃取柱对五氯苯酚有良好的吸附保留性能,以2mL的甲醇洗脱,洗脱效率在85%~95%之间。与传统的液液萃取相比,固相萃取的优势在于操作时间缩短、有机溶剂的使用量减少。     

典型药物及个人护理品在黄东海海域水体中的检测、分布规律及其风险评估

目前对沿海地区存在的药物及个人护理品(PPCPs)的了解十分有限,建立能同时精确检测海水样品中多种PPCPs的方法至关重要.本研究选取非甾体类消炎药、抗生素、脂质调节剂和兴奋剂等类别的9种PPCPs作为检测对象,建立固相萃取-高效液相色谱-质谱联用方法(SPE-HPLC-MS),确定了固相萃取柱的填料、洗脱液组成及用量等最佳实验条件.结果表明,萃取柱为CNW HLB,洗脱液为甲醇∶乙腈(1∶1,体积比),洗脱液体积为6 m L,水样pH为7,流速为5 m L·min~(-1),螯合剂EDTA-Na_2添加量为1 g,且浓缩倍数为500倍时,萃取效果最佳.9种PPCPs的线性回归方程均具有良好线性,相关性系数均大于0. 999,回收率在82%～106%之间,相对标准偏差在1. 6%～14%之间,检出限在0. 01～2 ng·L~(-1)之间,满足海水中痕量分析的要求.于2018年夏季对黄东海表层水体中PPCPs的分布特性、来源和分布规律进行研究.9种PPCPs均被检出,主要污染物是NAP、IBU、GEM、CAF和ASA.在空间分布上,PPCPs浓度整体呈现河口近岸高,远海海域较低的趋势,黄海海域中PPCPs浓度高于东海,这与黄海海域污染源多、其水交换能力与东海相比较弱有关.主成分分析结果显示,表层海水中的PPCPs浓度与盐度和pH之间具有负相关性,与叶绿素a具有一定正相关性,表明PPCPs的主要来源为陆源输入.运用风险熵值法对该海域的PPCPs进行环境风险评估,9种PPCPs的RQ均小于1,其中IBU和NAP的RQ大于0. 1,可能对该海域产生中度风险危害,其余PPCPs的RQ均小于0. 1,表明其目前对黄海及东海海域基本没有危害.     

Optimization of enrichment processes of pentachlorophenol (PCP) from water samples

The method of enriching PCP( pentachlorophenol ) from aquatic environment by solid phase extraction (SPE) was studied.Several factors affecting the recoveries of PCP, including sample pH, eluting solvent, eluting volume and flow rate of water sample, were optimized by orthogonal array design(OAD). The optimized results were sample pH 4; eluting solvent, 100% methanol; eluting solvent volume, 2 ml and flow rate of water sample, 4 ml/min. A comparison is made between SPE and liquid-liquid extraction(LLE) method. The recoveries of PCP were in the range of 87.6%-133.6% and 79%-120.3% for SPE and LLE, respectively. Important advantages of the SPE compared with the LLE include the short extraction time and reduced consumption of organic solvents. SPE can replace LLE for isolating and concentrating PCP from water samples.     

基于固相萃取的水中多种有毒有害有机污染物富集方法优化

以降低固相萃取杂质、提高目标化合物的回收率为目的,提出了一种基于固相萃取的水中多种有毒有害有机污染物富集方法.用丙酮和二氯甲烷等溶剂洗脱未上样的固相萃取柱,评价了固相萃取各个环节对正构烷烃、酞酸酯等杂质浓度的贡献值,发现85%杂质来自填料的溶出物(以Waters Oasis HLB为例).填料经二氯甲烷、丙酮、甲醇依次索氏提取24 h后,填料的溶出物明显减少,气相色谱图中杂质峰的数量和强度均明显降低.比较了6种常用固相萃取填料在索氏提取后对lgKow1.46～8.1之间的农药、多环芳烃、酚、酞酸酯等40种目标化合物的回收率,发现Waters Oasis HLB在改性聚苯乙烯-二乙烯基苯填料中回收率最高,平均为77%;Waters SepPak AC-2在活性炭填料中回收率最高,对农药的平均回收率为74%.WatersOasis HLB和Waters SepPak AC-2固相萃取柱串联后,目标化合物的回收率明显提高,平均为87%.     

GC-ECD测定地表水中的硝基苯类和氯苯类化合物

文章分别以液液萃取法和固相萃取法作为预处理方法,建立了地表水中12种硝基苯类和氯苯类化合物的气相色谱-电子捕获检测器(GC-ECD)分析检测方法,其中包括1,2-二硝基苯、1,3-二硝基苯、1,4-二硝基苯,2-硝基氯苯、3-硝基氯苯、4-硝基氯苯、1,2,3,4-四氯苯、1,2,3,5-四氯苯、1,2,4,5-四氯苯、2,4-二硝基甲苯、2,4-二硝基氯苯、2,4,6-三硝基甲苯。通过对实验条件的优化,对100 mL水样的方法检出限为液液萃取0.05⁰.15μg/L,固相萃取0.100.15μg/L,固相萃取0.10⁰.16μg/L范围内,加标回收率分别为80.7%0.16μg/L范围内,加标回收率分别为80.7%⁸8.0%和74.2%88.0%和74.2%¹01%,相对标准偏差分别在1.8%101%,相对标准偏差分别在1.8%⁵.3%和3.7%5.3%和3.7%⁵.5%之间。应用所建立的方法,对上海市地表水样进行监测分析,12种目标物质仅检出硝基氯苯,浓度为ND5.5%之间。应用所建立的方法,对上海市地表水样进行监测分析,12种目标物质仅检出硝基氯苯,浓度为ND⁰.52μg/L,样品加标回收率为液液萃取72.5%0.52μg/L,样品加标回收率为液液萃取72.5%⁸1.9%,固相萃取67.0%81.9%,固相萃取67.0%⁹1.0%。     

Functionalized CMK-3 mesoporous carbon with 2-amino-5-mercapto-1,3,4-thiadiazole for Hg(II) removal from aqueous media

Ordered mesoporous carbon（CMK-3） was synthesized and functionalized with 2-amino-5-mercapto-1,3,4-thiadiazole groups（AMT-OCMK-3） for Hg（Ⅱ） removal from aqueous solution. The modified CMK-3 was characterized by X-ray diffraction, N2adsorption-desorption isotherm, scanning electron microscopy and Fourier transform infrared spectroscopy. The effects of solution pH, contact time, initial Hg（Ⅱ） concentration and matrix effect were studied. The adsorption data were successfully fitted with the Langmuir model, exhibiting high adsorption capacity of 450.45 mg/g of AMT-OCMK-3. In the solid-phase extraction system a series of experimental parameters such as sample flow rate, sample volume,eluent volume and concentration of the eluent solution have been investigated and established for preconcentration of Hg（Ⅱ） in aqueous solution. The results showed that the enrichment factor for Hg（Ⅱ） was 250, the precision（relative standard deviation（RSD）, %） for six replicate measurements was 2.05% and the limit of detection for Hg（Ⅱ） was achieved at0.17 μg/L.     

Detection of geosmin and 2-methylisoborneol by liquid-liquid extraction-gas chromatograph mass spectrum (LLE-GCMS)and solid phase extraction-gas chromatograph mass spectrum (SPE-GCMS)

Two sample preparation methods were introduced and compared in this paper to establish a simple, quick and exact analysis of geosmin and 2-methylisoborneol. LC-18 column was employed in solid phase extraction (SPE), 1.0 mL of hexane was adopted in liquid-liquid extraction (LLE), and the extracts were analyzed by gas chromatograph mass spectrum (GCMS) in selected ion mode. Mean recoveries of SPE were low for 2-methylisoborneol (2-MIB) and geosmin (GSM) with values below 50%. For LLE, the recoveries were satisfyingly above 50% for 2-MIB and 80% for GSM. Detection limits of the LLE method were as low as 1.0 ng/L for GSM and 5.0 ng/L for 2-MIB. A year-long investigation on odor chemicals of drinking water in Shanghai demonstrated that in the summer, there was a serious odor problem induced by a high concentration of 2-MIB. The highest concentration of 152.82 ng/L appeared in July in raw water, while GSM flocculation was minimal with concentrations below odor threshold.