液相色谱串联质谱法测定水果中复硝酚钠残留量

以甲醇提取样品,采用超高效液相色谱串联质谱法(UPLC–MS/MS)测定水果中复硝酚钠的残留量。以甲醇–10 mmol/L乙酸铵水溶液(体积比为60∶40)为流动相,质谱采用电喷雾负离子MRM检测模式。对硝基苯酚钠和5-硝基愈创木酚钠的线性范围为0.05~2.00 mg/L,检出限为0.01 mg/kg,邻硝基苯酚钠的线性范围为2.5~100.0 mg/L,检出限为0.5 mg/kg,线性相关系数均大于0.995。实际样品中对硝基苯酚钠、邻硝基苯酚钠和5-硝基愈创木酚钠的加标回收率分别为83.0%~93.4%,81.0%~87.4%,83.0%~91.8%,测定结果的相对标准偏差小于7%(n=6)。该法操作简单、快捷,精密度、准确度高,适用于水果中复硝酚钠的残留分析。     

固相萃取-液相色谱-串联质谱法测定蔬菜中4种有机磷农药及其代谢产物

在蔬菜种植中经常使用的有机磷农药马拉硫磷、甲基对硫磷、敌百虫及乙酰甲胺磷可能转化的主要代谢产物分别为O,O-二甲基二硫代磷酸酯、对硝基酚、敌敌畏及甲胺磷。根据蔬菜色素等基质的含量不同采用不同的净化方法,色素含量高的蔬菜采用活性炭和弗罗里硅土串联固相萃取小柱净化,其他蔬菜采用弗罗里硅土固相萃取小柱净化。色谱分离选择ACQUITY UPLC BEH HILIC色谱柱,以乙腈和5 mmol/L乙酸铵水溶液为流动相进行梯度洗脱,得到的分离效果较好;质谱采用电喷雾正或负离子电离、多反应监测模式检测。液相色谱-质谱检测的基质效应为15.3%~45.1%;4种有机磷农药及其代谢物的方法回收率为76.9%~102.8%,相对标准偏差为5.92%~10.19%;定量限范围为0.001~0.01 mg/L;在0.01~1.00 mg/L范围内线性相关系数为0.9982~0.9999。方法具有良好的回收率、相对标准偏差、定量限及线性关系,适合蔬菜中有机磷及代谢物的检测,应用该检测方法对农贸市场购买的白菜、辣椒、西红柿及洋葱进行了检测。     

高效液相色谱-大气压化学电离-串联质谱法同时测定动物源食品中复硝酚钠的3种组分

复硝酚钠(SNP)是一种生长调节剂,在我国动物源食品检测中被列为禁用药物。由于复硝酚钠痕量分析方法不成熟,至今尚无标准检测方法,因此建立复硝酚钠中3种组分(5-硝基愈创木酚钠、对硝基酚钠和邻硝基酚钠)同时检测的方法对我国动物源食品中复硝酚钠残留水平的控制、检测标准的制定和政府相应管理措施的实行采取具有一定的理论和现实意义并兼具创新性。研究建立了高效液相色谱-大气压化学电离-串联质谱(HPLC-APCI-MS/MS)对猪肉、鸡肉、鱼肉和肝脏中复硝酚钠3种组分残留量的检测方法。样品采用氢氧化钠溶液提取,用盐酸调节pH值为酸性后,加氯化钠使溶液饱和,再用乙腈溶液反萃两次后,合并上清液并加入饱和氯化钠溶液,再经正己烷液液萃取除脂后吸出中间乙腈层,浓缩并定容后,以甲醇-水溶液作为流动相进行梯度洗脱,采用CORTECT C₁₈色谱柱分离,大气压化学电离,在多反应监测(MRM)负离子模式下测定,外标法定量分析。5-硝基愈创木酚钠、对硝基酚钠和邻硝基酚钠分别在0.5~10、1.0~20和2.5~50 μg/L范围内线性良好,定量限分别为1.0、2.0和5.0 μg/kg,在定量限、2倍定量限和10倍定量限加标水平上的回收率分别为81.5%~98.4%、81.5%~102%和81.4%~95.1%,相对标准偏差分别为1.51%~5.98%、1.10%~8.85%和0.91%~8.61%(n=6),均符合要求,能够满足动物源食品中复硝酚钠残留量的检测要求。     

β-环糊精交联树脂-紫外可见吸收光谱分析对硝基酚

以合成的β-环糊精交联树脂为吸附剂,紫外可见光谱分析微量对硝基酚.在碱性条件下,考察了对硝基酚在β-环糊精交联树脂上的吸附行为.在0.02 mol/L NaOH 介质中,室温下吸附30 min,树脂能有效分离富集对硝基酚,以甲醇-水(1:1, V/V)溶液为洗脱液,树脂能重复利用.此方法线性范围是0.5～90 mg/L,检出限为0.15 mg/L,测定结果令人满意.     

高效液相色谱-串联质谱法测定黄瓜、草莓中乙嘧酚和二甲嘧酚

建立了黄瓜、草莓中高效液相色谱-串联质谱同时检测乙嘧酚和二甲嘧酚残留的方法。样品加入乙腈高速匀浆,提取液中加入无水MgSO4和NaCl,振荡离心后,取上清液经分散固相萃取净化,液相色谱-串联质谱电喷雾正离子扫描同时分析乙嘧酚和二甲嘧酚。以黄瓜、草莓为基质进行3档添加水平和5次重复性实验,结果表明,添加量为0.01～1 mg/kg,乙嘧酚和二甲嘧酚的平均回收率为77.6%～99.3%,RSD为1.1%～6.8%,乙嘧酚和二甲嘧酚的方法检测限均为2.0μg/kg,定量限分别为6.0和5.0μg/kg。     

气相色谱-负化学源-质谱法检测水中10种全氟羧酸化合物

建立了气相色谱-负化学源-质谱（GC-NCI-MS）检测水中10种全氟羧酸化合物的分析方法。使用硅烷衍生化试剂N-甲基-N-三甲基硅基三氟乙酰胺（MSTFA）对全氟羧酸化合物进行衍生化，水样经弱阴离子交换固相萃取柱净化富集后进样。实验优化了样品前处理、衍生化和仪器条件。结果表明，10种全氟羧酸化合物在0.1~10 mg/L范围内线性关系良好，相关系数为0.9956~0.9993；方法的检测限（LOD）和定量限（LOQ）分别为0.5~1.5 μg/L和1.5~4.5 μg/L。在空白水样中进行了3个添加水平的加标回收试验，10种全氟羧酸化合物的平均回收率为70.2%~112.6%，相对标准偏差（RSD）为2.1%~14.5%（n=6）。该法原理简单，灵敏度高，准确、精密，可实现水体中10种全氟羧酸化合物同时检测的要求。     

微管纸喷雾质谱法快速筛查血液中5种强极性毒物

采用微管纸喷雾质谱法快速筛查了血液中的敌草快、百草枯、草甘膦、草铵膦和氯化琥珀胆碱5种强极性毒物.全血样品用9倍样品体积的甲醇提取,静置后取上清液直接上样,使用多反应监测扫描模式,每个化合物测定两个离子进行定性和定量分析.5种极性物质可在1 min内完成检测.该方法对5种极性毒物的检出限分别为敌草快0.05 mg/L,...     

邻-硝基酚分子印迹聚合物为涂层固相萃取搅拌棒的制备及其萃取性能研究

以邻-硝基酚为模板,甲基丙烯酸二甲胺乙酯和4-乙烯基吡啶为混合单体,利用整体材料"原位"聚合技术制备分子印迹聚合物为涂层的固相萃取搅拌棒(MIP-SBSE)。考察了制备条件对MIP-SBSE选择吸附性能的影响,并与高效液相色谱-二极管阵列检测器联用,探讨MIP-SBSE对环境水样中邻-硝基酚及其它酚类物质的选择萃取性能。考察了样品基底中离子强度、pH值以及吸附时间和解吸时间等萃取条件对目标化合物选择性能影响。结果表明,在最佳萃取条件下,MIP-SBSE对模板分子及其它酚类物质具有一定选择性能和较高的富集能力,对邻-硝基酚的线性范围为3.0～200μg/L;检出限LOD(S/N=3)为0.13μg/L;定量限LOQ(S/N=10)为0.40μg/L。在实际样品分析中,模板分子加标回收率为83.4%～120.9%;其它酚类物质的加标回收率在59.8%～129.0%之间。     

一种二维吖嗪共价有机骨架材料涂层毛细管的制备及其用于开管-毛细管电色谱分离硝基苯酚类环境内分泌干扰物

作为一种新型多孔晶体材料,共价有机骨架材料（COFs）由于具有比表面积大、密度小、稳定性高及孔径可调等特点而在诸多领域中得到了广泛的应用。但将其用作固定相以提高开管-毛细管电色谱（OT-CEC）分离效率的研究报道较少。鉴于此,该文参考文献方法合成了一种二维吖嗪COF（ACOF-1）,然后以ACOF-1作为固定相制备了ACOF-1涂层毛细管并以其为分离通道建立了一种分离硝基苯酚类环境内分泌干扰物（EEDs）的OT-CEC新方法。通过X射线粉末衍射、傅里叶变换红外光谱和扫描电子显微镜等表征手段证明成功合成并制备了ACOF-1和ACOF-1涂层毛细管。实验结果表明,在最佳分离条件下,所建立的OT-CEC方法可在20 min内实现2-硝基苯酚、4-硝基苯酚、2,4-二硝基苯酚和2,4,6-三硝基苯酚4种硝基苯酚分析物的基线分离。4种分析物的线性范围分别为10~500 mg/L和20~1000 mg/L,决定系数均大于0.99,检出限和定量限分别为0.13~0.23 mg/L和0.45~0.60 mg/L。迁移时间和峰面积的日内、日间及柱间相对标准偏差均不超过9.4%,表明所建立的方法重现性好,稳定性高,可用于硝基苯酚类EEDs的分离检测。分离机理研究表明ACOF-1孔结构对各分析物的尺寸选择作用是影响分离行为的主要因素。该工作证明了以COFs作为固定相的OT-CEC方法用于分离检测EEDs的可行性,后续将继续围绕COFs涂层毛细管的制备及其用于OT-CEC分离测定EEDs开展研究。     

高效液相色谱柱后衍生测定脱水蔬菜中的亚硫酸盐

建立了检测脱水蔬菜中亚硫酸盐的反相硅胶柱净化-柱后衍生-高效液相色谱方法.样品经甲醛提取,通过反相硅胶固相萃取小柱净化,采用Discover ODS-C18柱,流动相为0.005 mol/L氢氧化四丁基铵和乙腈,在碱性条件下以5,5’-二硫代双(2-硝基苯甲酸)为柱后衍生化试剂,445 nm检测.实验结果表明,在0.050～50.00 mg/L浓度范围内,相关系数为0.9987,方法的检出限和定量限分别为1 mg/kg和2 mg/kg,添加浓度在2～900mg/kg范围内,平均添加回收率为62％～88％,相对标准偏差不大于7.8％.该法能有效地避免脱水蔬菜中亚硫酸盐测定的假阳性结果,可满足实际检测工作的需要.     

聚乙烯吡烙烷酮修饰碳糊电极-双通道毛细管电泳安培法测定环境中的硝基酚

建立了几种硝基酚的聚乙烯吡烙烷酮修饰碳糊电极-双通道毛细管电泳安培检测的新方法.采用双工作电极和两台伏安仪,将样品的检测电位分别设定在氧化电位(+0.5V_vs.SCE)和还原电位(-1.4V_vs.SCE),在一个检测池中同时获得所有样品的氧化和还原信息,以还原电流和氧化电流值之比(Nc=ir/io)作为定性依据,对样品的纯度进行确证.通过优化工作电极、检测电位、缓冲溶液、β-CD和乙醇浓度等实验参数,实现了几种硝基酚的分离检测,同时采用样条小波最小二乘法对样品数据信号进行处理,并将此法应用于实际样品的测定.     

痕量硝基酚的反相高效液相色谱电化学检测

本文以甲醇与０．０３ｍｏｌ／Ｌ邻苯二甲酸氢钾缓冲液为淋洗液，采用安培型电化学检测，实现了２－硝基苯酚，３－硝基苯酚，４－硝基苯酚及２，４－二硝基苯酚和２，６－０二硝基苯酚等五种酚类化合物于Ｐｅｒｋｉｎ－Ｅｌｍｅｒ Ｎｕｃｌｅｏｓｉｌ Ｃ８柱上反相高效液相色谱的分离及在Ｅ＝＋１．２Ｖ时于玻碳电极上的同时检测。     

Multiresidue analysis of acidic and polar organic contaminants in water samples by stir-bar sorptive extraction-liquid desorption-gas chromatography-mass spectrometry

The feasibility of stir-bar sorptive extraction (SBSE) followed by liquid desorption in combination with large volume injection (LVI)-in port silylation and gas chromatography-mass spectrometry (GC-MS) for the simultaneous determination of a broad range of 46 acidic and polar organic pollutants in water samples has been evaluated. The target analytes included phenols (nitrophenols, chlorophenols, bromophenols and alkylphenols), acidic herbicides (phenoxy acids and dicamba) and several pharmaceuticals. Experimental variables affecting derivatisation yield and peak shape as a function of different experimental PTV parameters [initial injection time, pressure and temperature and the ratio solvent volume/N-(tert-butyldimethylsilyl)-N-methyltrifluoroacetamide (MTBSTFA) volume] were first optimised by an experimental design approach. Subsequently, SBSE conditions, such as pH, ionic strength, agitation speed and extraction time were investigated. After optimisation, the method failed only for the extraction of most polar phenols and some pharmaceuticals, being suitable for the determination of 37 (out of 46) pollutants, with detection limits for these analytes ranging between 1 and 800 ng/L and being lower than 25 ng/L in most cases. Finally, the developed method was validated and applied to the determination of target analytes in various aqueous environmental matrices, including ground, river and wastewater. Acceptable accuracy (70-130%) and precision values (<20%) were obtained for most analytes independently of the matrix, with the exception of some alkylphenols, where an isotopically labelled internal standard would be required in order to correct for matrix effects. Among the drawbacks of the method, carryover was identified as the main problem even though the Twisters were cleaned repeatedly.     

Cell-based biosensor for measurement of phenol and nitrophenols toxicity

A cost-effective whole cell biosensor based on electrochemical technique to detect toxicities of phenol and nitrophenols has been developed. This method relied on the inhibition effect for respiratory chain activity of microorganism by toxicant, which was measured by chronoamperometry using mediator (ferricyanide). The current signals produced by suspended microorganisms and reoxidation of ferrocyanide were transformed to inhibiting efficiency directly, and 50% inhibiting concentration (IC₅₀) was chosen as the quantitative standard of toxicity. The test microorganisms used here consist of three bacilli (Escherichia coli, Enterobacter cloacae and Alcaligenes faecalis), two pseudomonas (Pseudomonas fluorescens and Pseucomonas putida) and one fungus (Trichosporon cutaneum). 3,5-Dichlorophenol (DCP) was taken as the reference toxicant. The results showed that the microorganisms which belong to the same bacterial family had similar trends of inhibitions on respiratory activity and similar IC50 values. By comparing the IC₅₀ values, P. fluorescens was the most sensitive one to DCP toxicity, its IC₅₀ was estimated to be 4.2 mg/L. pH 7.0 and together with the standard glucose-glutamic acid (GGA) as an exogenous material were taken for optimum conditions in this study. Here, P. fluorescens as model test microorganism was employed to assess toxicities of phenol and nitrophenols under the optimum conditions. IC₅₀ values of 291.4 mg/L for phenol, 64.1 mg/L for 2-NP, 71.4 mg/L for 3-NP and 14.0 mg/L for 4-NP were determined at 60 min, respectively. Comparison with the results of published data has confirmed that this cell biosensor is a sensitive and rapid alternative to toxicity screening of chemicals.     

反相离子对高效液相色谱法分离测定钪、锡和铝

 以 1,2 二苯乙烯 4,4′ 双 (1 偶氮 ) 3,4 二羟基苯 2 ,2′ 二磺酸铵 (芪唑 )为柱前衍生试剂 ,采用反相离子对高效液相色谱法分离和测定钪、锡和铝。在C18柱上 ,用含 2 0mmol/LHAc NaAc缓冲溶液 (pH 6 0 )和 10mmol/L十二烷基磺酸钠的甲醇水溶液作流动相 ,检测波长 5 0 0nm ,同时分离测定了钪、锡和铝的络合物。钪、锡和铝的检出限分别为 0 9μg/L ,1 0 μg/L和 1 2 μg/L ,此方法用于矿石样品分析获得满意结果。     

An interlaboratory study to evaluate potential matrix reference materials for herbicides in water

Matrix reference materials (MRM) are essential tools for the validation of analytical protocols. Nowadays, there are no such materials for the determination of herbicides in water. Pesticides stored in acetonitrile and stored on solid phase extraction (SPE) cartridges previously percolated with a water sample spiked with triazines and phenylureas have proven to be good candidates for reference materials because of their satisfactory stability under appropriate temperature conditions. To evaluate the behaviors of these materials containing pesticides and to be analyzed by liquid chromatography, a collaborative study including 15 laboratories has been organized. Observed reproducibility on candidate materials after the removal of extreme results was 16.1% for the vials with pesticides in acetonitrile (at around 0.125 mg/L) directly analyzed, 29.2% for a water sample spiked with the pesticides (at around 0.5 microg/L) analyzed after preconcentration on a cartridge and 26.7% for the cartridges previously percolated with a water containing the pesticides (250 mL at around 0.5 microg/L for each pesticide) analyzed after elution. Such dispersion values are quite compatible with the requirement of a further certification for such materials.     

QuEChERS-气相色谱-质谱法测定土壤中6种酰胺类除草剂残留

建立了QuEChERS-气相色谱-质谱同时测定土壤中乙草胺(acetochlor)、甲草胺(alachlor)、异丙甲草胺(metolachlor)、吡草胺(metazachlor)、丁草胺(butachlor)和丙草胺(pretilachlor)6种酰胺类除草剂的分析方法。土壤中残留的酰胺类除草剂用10 mL去离子水、10 mL乙腈和4 g NaCl提取,用N-丙基乙二胺(PSA)、C18、石墨化炭黑(GCB)和无水硫酸镁(MgSO4)净化,然后用气相色谱-质谱联用法测定。采用HP-5MS弱极性石英毛细管柱进行气相色谱分离,在电子轰击电离(EI)源模式下以选择离子监测(SIM)扫描模式检测。结果表明,6种酰胺类除草剂在0.01~1.00 mg/L范围内呈良好线性关系,相关系数(r)为0.999 6~1.000 0。在加标水平为0.025、0.10和0.50 mg/kg时,6种酰胺类除草剂的平均回收率为92.0%~108%,相对标准偏差为1.64%~8.25%(n=3)。方法的检出限为0.002~0.006 mg/kg,定量限为0.005~0.02 mg/kg。同常用的气相色谱-电子捕获检测(GC-ECD)法比较,该法可提高抗干扰能力,使6种酰胺类除草剂得到较好分离。方法所使用的有机溶剂种类和用量少,操作简单、快速,具有应用价值。     

Extraction of trace nitrophenols in environmental water samples using boronate affinity sorbent

In this research, the applicability of a new sorbent based on boronate affinity material is demonstrated. For this purpose, six strong polar nitrophenols were selected as models which are difficult to be extracted in neutral form (only based on hydrophobic interactions). The extracted nitrophenols were separated and determined by high-performance liquid chromatography with diode array detection. The sorbent was synthesized by in situ copolymerization of 3-acrylamidophenylboronic acid and divinylbenzene using dimethyl sulfoxide and azobisisobutyronitrile as porogen solvent and initiator, respectively. The effect of the preparation parameters in the polymerization mixture on extraction performance was investigated in detail. The size and morphology of the sorbent have been characterized via different techniques such as infrared spectroscopy, elemental analysis, scanning electron microscopy and mercury intrusion porosimetry. The important parameters influencing the extraction efficiency were studied and optimized thoroughly. Under the optimum extraction conditions, the limits of detection (S/N = 3) and limits of quantification (S/N = 10) for the target nitrophenols were 0.097–0.28 and 0.32–0.92 μg/L, respectively. The precision of the proposed method was evaluated in terms of intra- and inter-assay variability calculated as RSD, and it was found that the RSDs were all below 9%. Finally, the developed method was successfully applied for environmental water samples such as wastewater, tap, lake and river water. The recoveries varied within the range of 71.2–115% with RSD below 11% in all cases. The results well demonstrate that the new boronate affinity sorbent can extract nitrophenols effectively through multi-interactions including boron–nitrogen coordination, hydrogen-bond and hydrophobic interactions between sorbent and analytes.     

PAN-蛋白质络合物的极谱吸附波及其应用

在0.05 mol/L HAc溶液中,PAN-牛血清白蛋白/人血清白蛋白络合物在-0.58 V(vs.SCE)处产生一灵敏吸附还原峰,峰电位较之游离PAN还原峰负约0.28 V,峰电流与牛血清白蛋白、人血清白蛋白浓度在0.1～12 mg/L,0.1～11 mg/L范围内呈线性关系;检测限均为0.05 mg/L。运用该法测定了人血清样品蛋白质含量。     

Optical fibre chemical sensor for trace vanadium(V) determination based on newly synthesized palm based fatty hydroxamic acid immobilized in polyvinyl chloride membrane

Fatty hydroxamic acid (FHA) immobilized in polyvinyl chloride (PVC) has been studied as a sensor element of an optical fibre chemical sensor for V(V). By using this instrument, V(V) in solution has been determined in the log concentration range of 0-2.5 (i.e. 1.0-300 mg/L). The detection limit was 1.0 mg/L. The relative standard deviation (R.S.D.) of the method for the reproducibility study at V(V) concentration of 200 mg/L and 300 mg/L were calculated to be 2.9% and 2.0%, respectively. Interference from foreign ions was also studied at 1:1 mole ratio of V(V):foreign ions. It was found that, Fe(III) ion interfered most in the determination of vanadium(V). Excellent agreement with ICP-AES method was achieved when the proposed method was applied towards determination of V(V).