磁性石墨烯纳米粒子固相萃取与气相色谱-质谱相结合测定环境水样中的三嗪类除草剂

将磁性石墨烯作为磁性固相萃取的吸附剂与气相色谱-质谱(GC-MS)相结合建立了环境水样中7种三嗪类除草剂残留的测定新方法。对影响萃取效率的一些因素如吸附剂用量、萃取时间、样品溶液的pH值、离子强度和解吸条件等进行了优化。在优化的实验条件下,7种三嗪类除草剂的富集倍数在574~968之间。测定西玛津、扑灭津、嗪草酮、西草净、氰草津的线性范围为0.01~10.0 μg/L,莠去津的线性范围为0.05~10.0 μg/L,扑灭净的线性范围为0.01~8.0 μg/L。线性相关系数为0.9968~0.9998,检出限(S/N=3)为1.0~5.0 ng/L。将本方法应用于井水、自来水和湖水等实际水样的分析,在0.5 μg/L和2.0 μg/L下的加标回收率为79.8%~118.3%,相对标准偏差为3.6%~10.5%。该法操作简单、富集倍数高,可满足水样中三嗪类除草剂残留的检测要求。     

微波萃取/气相色谱-质谱测定土壤中的多氯联苯

分别对多氯联苯的微波萃取条件进行了优化。优化后的分析条件为微波功率1200 W,萃取温度115℃,萃取时间20 min,萃取溶剂为V(正己烷)∶V(丙酮)=1∶1。方法的检出限为20~30 ng/g,线性范围40~4000 ng/mL(多氯联苯总量),相关系数均大于0.9990,样品基体加标回收率为92.2%~115%,相对标准偏差为9.4%(n=6)。     

磁性氮掺杂石墨烯固相萃取环境水样中的4种有机氯污染物

采用化学共沉淀法成功合成了磁性氮掺杂石墨烯纳米材料, 对其吸附性能进行了初步探讨.此磁性纳米材料对对氯间二甲苯酚的吸附不局限于均匀的单分子层吸附,吸附动力学符合准二级动力学模型.将其作为磁性固相吸附剂,通过对吸附剂用量、超声萃取时间、水样pH值、上样体积等条件的优化,建立了超声辅助磁性固相萃取-气相色谱/串联质谱同时测定环境水样中的三氯生(TCS)、对氯间二甲苯酚(PCMX)、六氯苯(HCB)和2,2′,4,4′,5,5′-六氯联苯(PCB-153) 4种有机氯污染物的方法. 在优化条件下,将6.0 mg Fe3O4/N-G分散于100 mL水样中,调节水样至pH 5,超声萃取15 s,磁性分离,3 mL乙醇和2 mL二氯甲烷分步洗脱,洗脱液氮吹定容,进行气相色谱-质谱联用分析.4种有机污染物在0.1~10 μg/L范围内与峰面积呈良好的线性关系,相关系数为0.9983~0.9999,检出限(S/N=3)和定量限(S/N=10)分别为0.05~0.6 ng/L和0.4~2.4 ng/L,3个加标浓度水平的回收率为68.3%~103.4%,日内、日间测定的相对标准偏差分别为3.3%~6.9%和3.4%~9.4%(n=6).本方法简单方便,易于操作,适用于环境水样中有机氯污染物的检测.     

磁性纳米材料固相萃取/火焰原子吸收光谱法测定环境水样中的痕量银离子

在纳米四氧化三铁表面包覆二氧化硅,并以十八烷基三甲氧基硅烷进行化学修饰,用作固相萃取吸附剂富集环境水样中的痕量银离子,用火焰原子吸收光谱法测定,建立了一种灵敏、快速、简便分析银离子的新方法。考察了水样pH值、吸附剂用量、螯合剂用量、振荡时间、洗脱剂、共存离子等对银离子回收率的影响。实验结果表明,对于200 mL水样,在pH 7.0、吸附剂用量为0.1 g、螯合剂5-Br-PADAP(0.5 g/L)用量为0.6 mL、吸附时间为10 min的条件下,材料对Ag+具有较好的吸附性,且用6 mL 1.0 mol/L的硝酸可完全洗脱所吸附的Ag+。在优化实验条件下,检出限(3σ)为0.15μg/L,相对标准偏差(10μg/L,n=6)为1.4%,富集因子达31。分别对河水、湖水样品中Ag+进行检测,加标回收率为85.0%~94.8%。     

分散液-液微萃取/高效液相色谱法测定水样中的痕量双酚A

建立了分散液-液微萃取与高效液相色谱联用技术测定水样中痕量双酚A(BPA)的方法. 通过对实验条件的筛选及优化, 得到最佳条件: 22.5 μL氯苯作萃取剂、0.5 mL丙酮作分散剂、0 min静止萃取时间、调节pH 3.2左右、10%离子强度及9 mL水样体积. 此条件下方法的线性范围为0.5~100 μg/L(R2=0.9941), 检出限为0.10 μg/L. 在BPA质量浓度为1 μg/L条件下, 方法回收率为87.8%~111.0%, 相对标准偏差8.3%(n=5), 富集倍数范围1905~2527. 对添加不同BPA浓度的自来水、地表水及回用中水进行分析, 回收率分别为(108±11.1)%, (107±13.2)%及(81.2±6.2)%(n=3). 在既定的色谱条件下, BPA的测定不受乙炔基雌二醇、雌二醇、雌三醇、雌酮和壬基酚等雌激素的干扰.     

涡旋辅助分散液液微萃取-悬浮固化/高效液相色谱法测定水样中7种萘二酚

建立了水样中7种萘二酚的涡旋辅助分散液液微萃取-悬浮固化/高效液相色谱(VA-DLLMESFO/HPLC)测定方法。以乙醚-十二醇为二元微萃取剂,通过涡旋分散方式协同萃取水样中的目标化合物,采用C18色谱柱分离,HPLC测定。优化了萃取剂及用量、萃取时间、氯化钠用量等条件。最佳萃取条件为:萃取剂为100μL乙醚和50μL十二醇,氯化钠用量为0.2 g/m L,涡旋萃取3 min。在优化条件下,7种萘二酚在一定质量浓度范围内线性关系良好,相关系数均大于0.997,方法检出限(S/N=3)为1.7~6.0μg/L;3个加标水平下的平均回收率为82.1%~106.0%,日内相对标准偏差(RSD,n=5)为1.2%~4.1%;中间添加水平的日间RSD(n=5)为2.5%~5.7%。该方法前处理简单,涡旋分散大大提高了物质传质速率,增大了萃取效率,缩短了萃取时间,是一种适用于水样中萘二酚类物质富集检测的绿色方法。     

气相色谱-质谱法同时测定地下水中42种半挥发性有机污染物

建立了同时测定地下水中多环芳烃(PAHs)、多氯联苯(PCBs)、有机氯农药(OCPs)和有机磷农药(OPPs)等42种半挥发性有机污染物的分析方法,对固相萃取、液-液萃取、萃取溶剂和色谱柱等分析条件进行优化。最终采用乙酸乙酯-正己烷(1∶4)液液萃取,DB-5MS色谱柱分离,GC-MS/SIM测定,内标法定量。结果表明,42种目标物在0.5~1 000μg/L范围内线性关系良好(r20.995);方法检出限为0.05~3.08 ng/L。在10、40、400 ng/L加标水平下,42种目标物的基体加标平均回收率为73.0%~107%,相对标准偏差(RSD,n=5)为1.4%~11.3%。将方法应用于石家庄周边地区水样检测,结果可靠。该方法灵敏、准确、简单易行,可显著提高地下水中主要有机污染物的分析效率。     

漩涡辅助离子液体-分散液液萃取环境水样中的紫外线吸收剂

建立了漩涡辅助离子液体-分散液液萃取(VA-IL-DLLME)的样品前处理技术,并与高效液相色谱联用检测环境水样中的紫外线吸收剂。以1-己基-3-甲基咪唑六氟磷酸为萃取剂,考察了离子液体用量、分散剂种类和用量、漩涡时间、离心时间、稀释剂种类和用量、p H等因素对萃取效率的影响。在最佳萃取条件下,2,4-二羟基二苯甲酮在4~1000 ng/m L、2-羟基-4-甲氧基二苯甲酮在3.5~1000 ng/m L、二苯甲酮,水杨酸-2-乙基己酯和3,3,5-三甲基环己烷水杨酸酯在10~1000 ng/m L浓度范围内具有良好的线性关系(R20.993),检出限为0.8~2.8 ng/m L,相对标准偏差(RSD)为2.6%~7.8%,加标回收率为55.8%~118.9%。方法可用于环境水样中痕量紫外线吸收剂的测定。     

石墨烯/聚二甲基硅氧烷涂层顶空固相微萃取与气相色谱联用测定环境水和果汁中菊酯农药残留

建立了石墨烯/聚二甲基硅氧烷涂层顶空固相微萃取与气相色谱在线联用测定环境水和果汁样品中6种菊酯类农药的检测方法。该涂层的萃取性能优于商用聚二甲基硅氧烷(PDMS,Polydimethylsilane)及聚丙烯(PA,Polypropylene)涂层。对影响萃取性能的因素(如萃取温度、离子强度、萃取时间及解吸时间)依次进行了优化。在最优条件下,丙烯菊酯与联苯菊酯的线性范围为0.02~5μg/L,甲氰菊酯、氯氰菊酯、氰戊菊酯的线性范围为0.1~20μg/L,溴氰菊酯的线性范围为0.2~20μg/L,其相关系数均高于0.99,检出限为6.8~58.2 ng/L,定量下限为18.2~154.9 ng/L。同一涂层的相对标准偏差(RSD,n=5)不高于9.2%,3根涂层之间的RSD为6.7%~10.8%。将该方法用于河水、鱼塘水、苹果汁和橙汁中6种菊酯残留的分析,加标回收率分别为81.6%~92.9%,82.3%~96.1%,78.2%~92.8%和79.9%~91.7%。方法简便、灵敏,能够满足环境水样及浓缩果汁样品中痕量农药残留的分析要求。     

SPME-GC联用测定环境水样中的酚类化合物

建立了固相微萃取与气相色谱联用技术测定环境水样中酚类化合物的方法. 探讨了pH、离子强度、萃取头类型、萃取时间以及解析时间等条件对酚类化合物萃取量的影响, 优化了GC仪器条件. 在优化的条件下, 酚类化合物的响应值与浓度有良好的线性关系, 线性范围为0.20～200 μg/L, 检出限在0.019～0.10 μg/L之间, 相对标准偏差(RSD, n=5)为4.4%～11%, 水样平均加标回收率为92.2%～101.9%, 所建立的方法可测定环境水样中的酚类化合物.     

固相萃取-高效液相色谱法同时检测水样中戊唑醇、乙霉威、晴菌唑、精甲霜灵和扑草净5种农药残留

利用石墨烯固相萃取柱萃取、高效液相色谱分离紫外检测,建立了戊唑醇、乙霉威、晴菌唑、精甲霜灵和扑草净5种农药同时检测的方法。确定的优化条件为:洗脱剂为5mL二氯甲烷、样品溶液的pH=7.0,样品体积为200mL。在此条件下,扑草净、戊唑醇、乙霉威、晴菌唑和精甲霜灵在0.05～100μg/L浓度范围内与峰面积呈良好的线性关系,相关系数为0.895～0.992;信噪比为3时,5种农药的检出限为1.2～5.2ng/L;方法的精密度为1.4%～4.6%。将本方法用于环境水样标准加入分析,相对回收率为80.5%～107.6%;相对标准偏差均小于5%。     

固相萃取-超高压液相色谱-串联质谱同时分析环境水样中四环素类和喹诺酮类抗生素

应用固相萃取及超高压液相色谱-质谱联用技术,建立了环境水样中4种四环素类和6种喹诺酮类抗生素的同时分析方法。样品经HLB固相萃取柱富集、净化后用甲醇洗脱,以超高压液相色谱-串联质谱仪多反应监测(MRM)离子模式定性、定量分析。以河水和海水为基质,卡巴氧为替代物进行回收率评价,4种四环素类抗生素在加标质量浓度分别为20.0 ng/L和100.0 ng/L时的回收率为94.0%～117.0%,相对标准偏差为2.0%～9.7%(n=4),方法的检出限均为20.0 ng/L;6种喹诺酮类抗生素在加标质量浓度分别为5.0 ng/L和20.0 ng/L时的回收率为63.6%～93.9%,相对标准偏差为1.6%～8.1%(n=4),方法的检出限为0.4 ng/L。结果表明,所建立的方法可成功地应用于近岸海域表层环境水样中目标抗生素残留的分析。     

Bamboo charcoal as adsorbent for SPE coupled with monolithic column-HPLC for rapid determination of 16 polycyclic aromatic hydrocarbons in water samples

The coupling of solid-phase extraction (SPE) using bamboo charcoal (BC) as an adsorbent with a monolithic column-high performance liquid chromatography (MC-HPLC) method was developed for the high-efficiency enrichment and rapid determination of 16 polycyclic aromatic hydrocarbons (PAHs) in water. Key influence factors, such as the type and the volume of the elution solvent, and the flow rate and the volume of the sample loading, were optimized to obtain a high SPE recovery and extraction efficiency. BC as an SPE adsorbent presented a high extraction efficiency due to its large specific surface area and high adsorption capacity; MC as an HPLC column accelerated the separation within 8 min because of its high porosity, fast mass transfer, and low-pressure resistance. The calibration curves for the PAHs extracted were linear in the range of 0.2-15 μg/L, with the correlation coefficients (r(2)) between 0.9970-0.9999. This method attained good precisions (relative standard deviation, RSD) from 3.5 to 10.9% for the standard PAHs I aqueous solutions at 5 μg/L; the method recoveries ranged in 52.6-121.6% for real spiked river water samples with 0.4 and 4 μg/L. The limits of detection (LODs, S/N = 3) of the method were determined from 11 and 87 ng/L. The developed method was demonstrated to be applicable for the rapid and sensitive determination of 16 PAHs in real environmental water samples.     

分散液-液微萃取-高效液相色谱法测定环境水样中的多环芳烃

建立了简便、快速、有效的分散液-液微萃取-高效液相色谱-荧光检测(DLLME-HPLC-FLD)测定环境水样中15种多环芳烃(PAHs)的方法。重点探讨了萃取剂的种类和用量、分散剂的种类和用量以及萃取时间等对PAHs萃取效率的影响。在优化的条件下,评价了方法的可靠性。15种PAHs在0.01～10 μg/L范围内呈良好的线性关系,相关系数r均不小于0.9913,峰面积的相对标准偏差(RSD)在2.3%～4.7%之间(n=6)。在优化条件下,富集因子和萃取回收率良好,分别为674～1032和67.4%～103.2%,15种PAHs的检出限(S/N=3)在0.0003～0.002 μg/L之间。建立的方法应用于敖江水样中PAHs的检测,平均加标回收率在79.5%～92.3%之间,RSD在4.3%～6.7%范围内(n=5)。该方法适用于环境水样中痕量PAHs的分析。     

中空纤维支载离子液体液液微萃取法检测环境水体中的三氯生

三氯生(5 Chloro-2-(2,4-dichlorophenoxy) phenol,TCS)是一种新型环境水体污染物,具有潜在的生态与健康风险,因此发展合适的分析方法来检测水环境中这类化合物极其必要.本研究以1-辛基-3-甲基咪唑六氟磷酸离子液体( [C8 MIM][PF6])为萃取剂,基于中空纤维的离子液体液液微萃取方法,结合HPLC/UV用于环境水样中TCS的分析测定;通过对各参数(萃取剂、供体相的体积、供体相pH值、离子强度、萃取时间等)的优化在最优条件下(样品相体积为50 mL,pH值2,盐浓度为0.2 mol/L,200 r/min振荡萃取8 h),获得了较高的富集倍数(907倍)、较低的检出限(0.05 μg/L,RSD=7.4％,n=6)和较好的线性范围(0.1～100 μg/L);以4种环境水样加标实验对方法的准确性进行评估,其回收率可达94.2％～108.5％(RSD=5.5％～8.0％,n=6);本方法可广泛应用于环境水体中痕量TCS的分析检测.     

Ionic liquid-based dispersive liquid-liquid microextraction for sensitive determination of aromatic amines in environmental water

Ionic liquid-based dispersive liquid-liquid microextraction was developed for the extraction and preconcentration of aromatic amine from environmental water. A suitable mixture of extraction solvent (100 μL, 1-butyl-3-methylimidazolium hexafluorophoshate) and dispersive solvent (750 μL, methanol) were injected into the aqueous samples (10.00 mL), forming a cloudy solution. After centrifuging, enriched analytes in the sediment phase were determined by HPLC-UV. The effect of various factors, such as the extraction and dispersive solvent, sample pH, extraction time and salt effect were investigated. Under optimum conditions, enrichment factors for 2-anilinoethanol, o-chloroaniline and 4-bromo-N,N-dimethylaniline were above 50 and the limits of detection (LODs) were 0.023, 0.015 and 0.026 ng/mL, respectively. Their linear ranges were 0.8-400 ng/mL for 2-anilinoethanol, 0.5-200 ng/mL for o-chloroaniline and 0.4-200 ng/mL for 4-bromo-N,N-dimethylaniline, respectively. Relative standard deviations (RSDs) were below 5.0%. The relative recoveries from samples of environmental water were in the range of 82.0-94.0%. Compared with other methods, dispersive liquid-liquid microextraction is simple, rapid, sensitive and economical.     

Ultrasound‐assisted magnetic SPE based on Fe3O4‐grafted graphene for the determination of polychlorinated biphenyls in water samples

An ultrasound‐assisted magnetic SPE procedure with an Fe₃O₄‐grafted graphene nanocomposite as the magnetic adsorbent has been developed to determine seven polychlorinated biphenyls (PCBs; PCB28, PCB52, PCB101, PCB118, PCB138, PCB153, and PCB180) simultaneously in 200 mL environmental water samples, in combination with GC–MS/MS. Several factors related to magnetic SPE efficiencies, such as the superparamagnetic intensity and amount of adsorbent, extraction time, sample pH, and desorption conditions were investigated. With the assistance of ultrasound, the extraction achieved the maximum within only 20 s, attributed to the powerful adsorptive ability of the magnetic adsorbent toward the PCBs. Under the optimized conditions, an excellent linearity was observed in the range of 0.1–100 ng/L for PCB28, 0.2–100 ng/L for PCB52, and 0.5–100 ng/L for the other five PCBs with the correlation coefficients ranging from 0.9988 to 0.9996. The mean recoveries at spiked levels of 5.0 and 10.0 ng/L were 84.9–108.5%, the coefficients of variations were <6.5%. With convenient magnetic separation, the synthesized magnetic adsorbent could be recycled more than ten times. The proposed method was demonstrated to be feasible, simple, rapid, and easy to operate for the trace analysis of the PCBs in environmental water samples.     

顶空固相微萃取-气相色谱-质谱联用测定饮用水中的2-甲基异莰醇和土臭素

2-甲基异莰醇(2-methylisoborneol, 2-MIB)和土臭素(geosmin, GSM)在水源水中大量分泌排放是造成饮用水土霉异味突发事件、引发居民用水恐慌的重用因素之一。使用顶空固相微萃取(HS-SPME)与气相色谱-质谱联用技术(GC-MS)建立了水库水、水库附近土壤、居民自来水中2-MIB和GSM的测定方法。结合正交分析优化了加盐量、萃取温度、萃取时间条件,在电子轰击(EI)-选择离子扫描(SIM)模式下进行了目标物的定性定量分析。结果表明:在5~1000 ng/L范围内,2-MIB和GSM的色谱峰面积与其质量浓度的线性关系良好(r²≥0.998), 2-MIB与GSM的检出限分别为0.72 ng/L和0.34 ng/L,定量限分别为2.40 ng/L和1.13 ng/L;目标物加标水平为10~600 ng/L时,平均回收率为93.6%~107.7%,相对标准偏差(RSD)≤6.1%(n=6)。基于上述方法,对辽宁省某地区水库水、水库附近土壤、居民自来水中的目标物进行检测,结果表明:水库水目标物质量浓度范围为3.0~3.6 ng/L,水库附近土壤中提取的2-MIB为8.1 ng/L、提取的GSM为17.8 ng/L,居民自来水中的目标物未检出。该方法操作简便、准确可靠,灵敏度高,无需有机溶剂,适合于饮用水中2-MIB和GSM的分析检测。     

Using Zn/Al layered double hydroxide as a novel solid-phase extraction adsorbent to extract polycyclic aromatic hydrocarbons at trace levels in water samples prior to the determination of gas chromatography–mass spectrometry

This paper demonstrates, for the first time, the great potential of using Zn/Al layered double hydroxide intercalated sodium dodecyl benzene sulfonate (Zn/Al-SDBS-LDH) as a solid-phase extraction (SPE) material in the extraction of persistent organic pollutants prior to the determination of gas chromatography-mass spectrometry in environmental water samples. Zn/Al-SDBS-LDH, a relatively inexpensive and simply prepared material, was synthesized and used as a SPE adsorbent to quantitatively determine the concentration of five polycyclic aromatic hydrocarbons (PAHs) in environmental water samples. Factors affecting extraction efficiency, such as, eluent type, eluent volume, flow rate of sample, sample volume, and amount of adsorbent, were investigated and optimized in detail. Experimental results indicate that there is an excellent linear relationship between peak area and the concentration of PAHs over the range of 5-500 ng L(-1), and the precisions (relative standard deviation (RSD)) were 2.5-6.3% under the optimum conditions. Based on the ratio of chromatographic signal-to-base line noise (S/N = 3), the limits of detection could reach 1.2-3.2 ng L(-1). This novel method was successfully applied to the analysis of PAHs in environmental water samples. As such, we show here that the use of Zn/Al-SDBS-LDH as SPE adsorbent materials, coupled with gas chromatography-mass spectrometry, is an excellent improvement in the routine analysis of PAHs at trace levels in the environment.