分散液液微萃取-气相色谱法测定水中苯、甲苯和二甲苯

以CHCl3为萃取剂,丙酮为分散剂,建立了基于分散液液微萃取(DLLME)结合气相色谱测定水样中苯、甲苯和二甲苯含量的新方法。实验对影响萃取效率的因素进行优化,萃取条件为:在1.0mL含有50g/LNaCl的样品溶液中加入40.0μLCHCl3和0.16mL丙酮,振荡分散均匀后,以400r/min离心5min,取萃取溶剂1.00μL直接进样分析。本方法线性范围为0.8～200μg/mL,相关系数r0.9980,检出限为0.1μg/mL,回收率分别在93.5%～102.1%之间。将该方法与液液萃取法、单滴微萃取相比较,具有操作简单、富集效率高和灵敏度高等特点。     

固相萃取-高效液相色谱/串联质谱法测定大鼠血浆中二十二碳六烯酸

建立了固相萃取-高效液相色谱/串联质谱(SPE-HPLC-MS/MS)测定大鼠血浆中二十二碳六烯酸(DHA)的分析方法。血浆样品经C18固相萃取(SPE)小柱净化后,采用Thermo C18色谱柱分离,以0.2%甲酸水溶液和乙腈为流动相,等度洗脱,在电喷雾离子源负离子模式下,采用质谱选择反应监测(SRM)模式检测,外标法定量。结果表明:DHA在0.10~60.0μg/mL范围内具有良好的线性关系(r2=0.9990);检出限(S/N=3)为0.04μg/mL,定量限(S/N=10)为0.10μg/mL;在2、10、30μg/mL 3个添加水平下,其平均回收率为94.0%~106.9%,方法的相对标准偏差(RSD)在2.15%~3.12%之间。该方法简单、快速,准确度、灵敏度高,适用于大鼠血浆中DHA的分析检测。     

LC-MS/MS检测蜂胶中硝基呋喃类代谢物的残留

建立了蜂胶中硝基呋喃类代谢物液相色谱-串联质谱检测方法。样品经固相萃取、衍生、乙酸乙酯提取后进行质谱分析。在1.0、2.0、5.0μg/kg 3个添加水平下,硝基呋喃类代谢物的平均回收率为92.6%～99.3%,日内相对标准偏差小于10%,日间相对标准偏差小于15%。在0.5～20 ng/mL范围内呈良好的线性(r>0.99),检测限为0.25μg/kg,定量限为1.0μg/kg。方法适用于蜂胶中硝基呋喃类代谢物的分析确证。     

高效液相色谱测定牛奶中邻苯二甲酸酯的方法研究

建立了针对欧盟指令2007/19/EC中禁止与食品接触的6种邻苯二甲酸酯(BBP、DBP、DEHP、DNOP、DINP和DIDP)的RP-HPLC测定方法.样品用甲醇、正己烷.甲基叔丁基醚(ⅥV=1:1)提取,经冷冻去脂、液液萃取和硅胶固相萃取净化后,用ODS柱(250×4.6mm,5μm)分离,UV 224 nm检测.结果表明,BBP和DBP在0.05～80μg/mL、DEHP和DNOP在0.1～80μg/mL、DINP和DIDP在0.5～80μg/mL的质量浓度范围内,峰面积与质量浓度呈线性关系,相关系数(r2)均大于0.998.方法检测限分别为:BBP 0.15μg/g、DBP 0.1μg/g、DEHP和DNOP 0.2μg/g、DINP和DIDP 0.6μg/g;6种PAEs的添加量在最大残留限量值的0.2、1和2倍时,其平均回收率为80.7%～102.3%,相对标准偏差为1.7%～9.0%.所建立的方法经济、准确、可靠,满足欧盟指令中6种邻苯二甲酸酯限量的检测要求.     

分散固相萃取-高效液相色谱法测定水产品中甲基睾丸酮的残留量

建立了水产品中甲基睾丸酮残留的分散固相萃取-高效液相色谱检测方法。样品加入无水硫酸镁后乙酸乙酯均质提取,提取液经中性氧化铝粉分散固相萃取、净化后上机检测。甲基睾丸酮的检出限为8μg/kg,在质量浓度为10~10 000ng/mL的范围内线性良好,相关系数为0.9999。对罗非鱼、草鱼、对虾及甲鱼进行3个水平(30,50,100μg/kg)的加标回收实验,回收率为84.6%~106%,相对标准偏差为1.77%~4.27%。方法适用于水产品中甲基睾丸酮残留的快速分析检测。     

聚合物整体柱微萃取与高效液相色谱联用检测水性化妆品中的性激素

建立了水性化妆品中睾酮、甲基睾酮和孕酮的聚合物整体柱微萃取和高效液相色谱联用检测方法。聚(甲基丙烯酸-乙二醇二甲基丙烯酸酯)毛细管整体柱作为萃取介质,表现出较大的萃取容量。实验优化了影响萃取效率的参数,包括萃取流速、样品溶液pH值、盐浓度以及有机相含量。样品经过磷酸盐溶液稀释和过滤后便可直接进行萃取分析。睾酮、甲基睾酮和孕酮在10～1000μg/L的浓度范围内具有良好的线性关系,相关系数均大于0.996;它们的检出限分别为2.3,2.8和4.6μg/L;日内及日间相对标准偏差分别小于7.7%和7.5%。本方法已成功地应用到实际样品检测中,3种性激素的加标回收率为83%～119%。     

气相色谱法检测纸质包装材料中9种有害物质

建立了快速测定纸质包装材料中甲苯、邻二甲苯、间二甲苯、对二甲苯、萘、十四烷、二苯甲酮、硬脂酸甲酯、邻苯二甲酸二丁酯9种有害物质的气相色谱法。纸质包装材料样品进行溶剂萃取,用气相色谱-氢火焰离子化检测器法同时测定样品的9种有害物质。对萃取剂、萃取温度和时间以及色谱条件进行了考察,方法的线性范围为0~100μg/mL,检测限为0.01~0.05μg/mL,回收率为91.7%~111.4%,相对标准偏差为3.59%~7.76%。该方法操作简单,定量准确可靠。     

固相萃取-加压毛细管电色谱法测定水体中8种农药残留

采用固相萃取-反相加压毛细管电色谱-紫外检测技术,建立了水体中乐果、敌敌畏、克百威、甲萘威、莠去津、甲基对硫磷、马拉硫磷、百菌清8种农药残留的同时检测方法。在最佳条件下,8种目标农药的线性范围分别为:3.4~100μg/mL、8.1~120μg/mL、1.2~50μg/mL、0.2~50μg/mL、0.1~50μg/mL、3.7~100μg/mL、11.2~150μg/mL、2.1~100μg/mL,相关系数为0.9961~0.9997;检出限(S/N=3)在0.03~3.7μg/mL之间,加标回收率在71.0%~114.1%范围,相对标准偏差(RSD)为1.1%~9.8%。该方法简单、可靠、适用于水中多种农药残留的同时分析测定。     

超声波辅助分散液相微萃取-气相色谱联用分析菌核净

将超声波萃取(USE)与分散液-液微萃取(DLLME)联合,利用气相色谱-电子捕获检测(GC-ECD),建立了一种高灵敏度检测水体中菌核净的新方法。对萃取的条件进行优化,选定萃取条件为:在5 mL样品中,注入1 mL丙酮和0.1 mL的四氯化碳混合液,20 Hz超声10 min,振荡混匀后高速离心5 min,移出下层溶剂低温吹干以丙酮定容自动进样分析。在优化条件下,样品的富集倍数可达50倍,检出限为0.001μg/mL,对采于蔬菜地边的水样进行加标回收率实验,平均回收率在81%以上,相对标准偏差在4.3%~7.6%之间,方法可满足水样中菌核净农药残留的检测要求。     

微波萃取-气相色谱法测定土壤中5种有机磷农药

建立微波萃取–气相色谱法测定土壤中5种有机磷农药的含量。样品以丙酮–二氯甲烷(1∶1)为萃取溶剂,采用硅胶小柱净化,浓缩后经火焰光度检测器检测。5种有机磷农药的质量浓度在0.010～0.500μg/mL范围内与色谱峰面积呈良好的线性关系,相关系数均大于0.998,方法检出限为2.33～3.66μg/kg。样品加标回收率为90%～103%,测定结果的相对标准偏差为1.54%～9.05%(n=6)。该方法操作方便、快速,结果准确、可靠,试剂用量少,缩短了分析时间,适用于土壤中有机磷农药的测定。     

Rapid determination of Δ-Tetrahydrocannabinol in saliva by polymer monolith microextraction combined with gas chromatography-mass spectrometry

A method was developed for the determination of Δ⁹-Tetrahydrocannabinol (THC) in saliva by polymer monolith microextraction (PMME) combined with gas chromatography-mass spectrometry. The poly(methacrylic acid-co-ethylene glycol dimethacrylate) (p(MAA-co-EGDMA)) monolithic capillary column was selected as the extraction medium of PMME, which showed high extraction capacity towards THC in saliva. To reach optimum PMME extraction performance, several PMME parameters were investigated, including matrix pH, flow rate for extraction, sampling volume and elution solvent. Under the optimal conditions, good extraction efficiency was obtained with no matrix interference in the process of extraction and the subsequent GC-MS analysis. In the selected-ion monitoring (SIM) mode, the limit of detection (LOD) for THC was 0.68 ng/mL. The linearity range of the method was 3-300 ng/mL. Excellent reproducibility of the method was exhibited by intra- and inter-day precisions, yielding the relative standard deviations (R.S.D.s) less than 12%; recoveries higher than 89%. The proposed method was proved to be rapid, sensitive, and competently applied to the determination of THC in saliva samples.     

聚合物整体柱微萃取-高效液相色谱法检测鸡蛋中的磺胺嘧啶和磺胺二甲嘧啶残留

建立了鸡蛋中磺胺嘧啶和磺胺二甲嘧啶残留量的聚合物整体柱微萃取和高效液相色谱检测方法。以聚(甲基丙烯酸-乙二醇二甲基丙烯酸酯)毛细管整体柱作为萃取装置。为了得到较高的萃取效率,优化了影响萃取效率的参数(萃取流速、萃取体积、样品基质pH值)。样品经过匀浆、乙醇提取、磷酸盐缓冲溶液稀释、离心等步骤后直接进行萃取。鸡蛋中磺胺嘧啶和磺胺二甲嘧啶的检出限分别为11.2 ng/g和8.8 ng/g,在50～5000 ng/g的浓度范围内具有良好的线性关系。加标回收率大于65%,日内、日间测定的相对标准偏差不高于8.2%。结果表明,方法简单、快速、灵敏度高,适用于鸡蛋中磺胺嘧啶和磺胺二甲嘧啶的常规分析。     

高效液相色谱-四极杆/静电场轨道阱高分辨率质谱法快速筛查中成药和保健食品中非法添加的42种化学药物

建立了高效液相色谱-四极杆/静电场轨道阱高分辨率质谱法快速筛查中成药和保健品中非法添加化学药物的方法。中成药和保健品样品,经提取溶剂提取,以12000 r/min离心后进行质谱分析。采用Phe-nomenex C18色谱柱(100 mm×4.6 mm,2.6μm)进行分离,以乙腈和0.1%甲酸溶液作为流动相,进行梯度洗脱。质谱采用正离子和负离子同时扫描,Fullms-dd-MS2模式进行分析。在所建立的色谱条件下,42种化学药物能够得到较好分离,在线性范围内线性关系良好,相关系数均大于0.99。通过加标验证,在20,50和100 ng/g加标水平下,所有分析物的平均回收率为69.3%~105.2%,相对标准偏差(RSD)小于8.9%。运用本方法对31种保健品和中成药进行快速筛查,发现其中3种添加了盐酸二甲双胍,1种添加了西地那非,1种添加了羟基莫豪西地那非。本方法样品处理过程简单,分析时间短,准确可靠,灵敏度高。适用于中成药和保健品中非法添加化学药品的定性与定量检测,可用于非法添加药物的筛查。     

新型强阳离子交换聚合物整体柱的制备及其在奶制品中三聚氰胺测定中的应用

在内径为530 μm的石英毛细管中原位聚合得到一种新的强阳离子交换聚合物整体柱2-丙烯酰胺-2-甲基-1-丙磺酸-乙二醇二甲基丙烯酸酯聚合物(poly(AMPS-co-EDMA))整体柱,并将其作为聚合物整体柱微萃取(PMME)的萃取介质。优化N,N-二甲基甲酰胺(DMF)和聚乙二醇(PEG)致孔体系的比例,制备得到的poly(AMPS-co-EDMA)整体柱渗透性好、机械强度高且在水溶液中具有良好的稳定性。通过考察样品溶液的pH值、盐浓度和有机溶剂含量对萃取效率的影响,证明该整体柱主要通过强阳离子交换和疏水相互作用对三聚氰胺进行萃取富集。在PMME与高效液相色谱联用技术的基础上,建立了检测奶制品中三聚氰胺含量的分析方法。奶制品中三聚氰胺的检出限和定量限分别为0.09 mg/kg和0.3 mg/kg,在0.5~80 mg/kg的含量范围内具有良好的线性关系,日内、日间测定的相对标准偏差不高于7.5%。结果表明,该方法简便、快速、灵敏度高且成本低,适合于奶制品中微量三聚氰胺的检测。     

Development of pressurized hot water extraction followed by headspace solid-phase microextraction and gas chromatography-mass spectrometry for determination of ligustilides in Ligusticum chuanxiong and Angelica sinensis

In this work, a simple, rapid, solvent-free, and low-cost method was developed for the determination of ligustilides in traditional Chinese medicines (TCMs), which was based on pressurized hot water extraction (PHWE) followed by headspace solid-phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS). The two bioactive compounds Z-ligustilide and E-ligustilide in two common TCMs, viz. Ligusticum chuanxiong and Angelica sinensis, were extracted by water at 150 degrees C and 40 bar, followed by concentration with HS-SPME and detection by GC-MS. PHWE and HS-SPME parameters were investigated and method validation (precision and recovery) was studied. It has been shown that the proposed method provides a powerful approach for quantitative analysis of ligustilides in TCMs. The method was applied to determination of ligustildes in the TCMs from different growing areas. The results indicate that PHWE-HS-SPME-GC-MS is a potential tool for TCM quality assessment.     

Analysis of ochratoxin A and ochratoxin B in traditional Chinese medicines by ultra-high-performance liquid chromatography–tandem mass spectrometry using [C20]-ochratoxin A as an internal standard

The paper reported a reliable analytical method for simultaneous determination of ochratoxin A (OTA) and ochratoxin B (OTB) in traditional Chinese medicines (TCMs) by ultra-high-performance liquid chromatography–tandem mass spectrometry (UHPLC–MS/MS). The development of the method and investigations on the matrix influence were described in particular. The matrix effects were thereby minimized by using a reliable internal standard and a simple sample pretreatment. The established method was further validated by determining the linearity (R² ≥ 0.9990), average recovery (86.3–114.2%), sensitivity (limit of quantitation 0.03–0.19 ng mL⁻¹) and precision (relative standard deviation ≤ 13.1%). It was shown to be a suitable method for simultaneous determination of OTA and OTB in various TCMs. Finally, a total of 51 TCMs widely used in China were screened for OTA and OTB with the proposed method. The results showed that only 4 samples were contaminated with ochratoxins at low levels, indicating that it was low risk of ochratoxins to consumers who occasionally used TCMs.     

Multiresidue analysis of beta-agonists in pork by coupling polymer monolith microextraction to electrospray quadrupole time-of-flight mass spectrometry

A novel method of polymer monolith microextraction (PMME) using poly(methacrylic acid-co-ethylene glycol dimethacrylate) monolith combined with electrospray ionization quadrupole time-of-flight mass spectrometry (ESI-QTOF MS) was developed for the rapid and sensitive determination of beta-agonists in pork samples. The conditions of PMME were optimized for the improvement of extraction efficiency and reduction of the matrix interferences from pork. Under the optimal condition, the eluate solution allowed direct analysis by mass spectrometry. In the positive ion mode and in the multiple reaction monitoring (MRM) mode, the limits of detection (LODs) for beta-agonists were found to be 0.08 ng/g (clenbuterol, CLB), 0.18 ng/g (salbutamol, SBTM) and 0.26 ng/g (terbutaline, TBTL) in pork, respectively, with good inter- and intra-day precisions (2-10% for CLB, 11-23% for SBTM and 4-16% for TBTL). The proposed PMME/ESI-QTOF MS method was successfully applied to the determination of beta-agonist residues in thirteen real samples, and the positive samples were confirmed according to the identification points (IPs) system defined by Commission Decision 2002/657/EC. To investigate the matrix effect, the proposed method was compared with PMME-HPLC/ESI-QTOF MS and the slight decrease in sensitivity of PMME/ESI-QTOF MS was ascribed to the inter-analyte ion suppression.     

Chromatographic fingerprinting and metabolomics for quality control of TCM

Chromatographic fingerprinting technique of traditional Chinese medicine (TCM) has proved to be a comprehensive strategy for assessing the intact quality of herbal medicine. In general, one could use the chromatographic techniques to obtain a relatively complete picture of herbal medicines, which are in common called chromatographic fingerprints of herbal medicines to represent the so-called phytoequivalence. Based on this, the features of chromatographic fingerprints of herbal medicines have been discussed in some detail. The technique based on chromatographic fingerprinting is essentially a kind of high-throughput and integral tools to explore the complexity of herbal medicines. In order to further control the comprehensive quality of TCMs, some new strategies are proposed to trace the chemical changes of chromatographic fingerprints both in product processing and/or after their administration by modern chromatographic techniques and chemometrics. Combined with metabolomics, it seems possible for one to reveal the working mechanism of TCMs and to further control their intrinsic quality. Finally, the intensive study of chromatographic fingerprinting coupled with multivariate analysis tools developed in bioinformatics and chemometrics are emphasized in order to achieve the aim to reveal the working mechanisms of TCMs and to further control and strengthen TCMs' intrinsic quality in a comprehensive manner.     

Rapid determination of panaxynol in a traditional Chinese medicine of Saposhnikovia divaricata by pressurized hot water extraction followed by liquid-phase microextraction and gas chromatography-mass spectrometry

Panaxynol is a bioactive component in traditional Chinese medicines (TCMs), such as Saposhnikovia divaricata and Panax ginseng. In the work, two solvent-free sample techniques of pressurized hot water extraction (PHWE) and headspace liquid-phase microextraction (HS-LPME) were combined and developed for the determination of panaxynol in a TCM of S. divaricata. Panaxynol in the TCM samples from different growing areas was extracted by PHWE in dynamic mode, followed by extraction and concentration with HS-LPME and analysis with gas chromatography-mass spectrometry (GC-MS). The PHWE and HS-LPME parameters were optimized and the method validations were studied. Panaxynol in S. divaricata from four different growing areas was quantitatively analyzed by internal standard method. These results have shown that PHWE-LPME-GC-MS is a simple, rapid, efficient and low-cost method for the determination of panaxynol in TCMs and is a potential tool for TCM quality assessment.     

Preparation, evaluation and application of molecularly imprinted solid-phase microextraction monolith for selective extraction of pirimicarb in tomato and pear

A simple, rapid and sensitive method for the determination of pirimicarb in tomato and pear using polymer monolith microextraction (PMME) based on the molecularly imprinted polymer (MIP) monolith combined with high-performance liquid chromatography-photodiodes array detector (HPLC-PAD) was developed. By optimizing the polymerization conditions, such as the nature of porogenic solvent and functional monomer, the molar ratio of the monomer and cross-linker, an pirimicarb MIP monolith was synthesized in a micropipette tip using methacrylic acid (MAA) as the functional monomer, ethylene dimethacrylate (EGDMA) as the cross-linker and the mixture of toluene-dodecanol as the porogenic solvent. The MIP monolith showed highly specific recognition for the template pirimicarb. The monolith was applied for the selective extraction of pirimicarb in tomato and pear. Several parameters affecting MIP-PMME were investigated, including the nature and volume of extraction solvent, sample volume, flow rate and sample pH. Under the optimum PMME and HPLC conditions, the linear ranges were 2.0-1400 μg/kg for pirimicarb in tomato and pear with the correlation coefficient of above 0.999. The detection limits (s/n=3) were both 0.6 μg/kg. The proposed method was successfully applied for the selective extraction and determination of pirimicarb in tomato and pear.