固相萃取-高效液相色谱-质谱联用法同时测定食品中9种人工合成甜味剂

建立了固相萃取-高效液相色谱-串联质谱快速检测食品中安赛蜜、糖精钠、甜蜜素、三氯蔗糖、阿斯巴甜、阿力甜、纽甜、甘素及新橙皮甙二氢查尔酮等9种人工合成甜味剂的方法。样品中的甜味剂经三乙胺缓冲溶液（pH 4.5）提取，采用亲水亲脂平衡填料固相萃取柱净化，经Phenomenex Knietex^® F5色谱柱（100 mm×2.1 mm，2.6 μm）分离，以0.1%（v/v）甲酸-5 mmol/L甲酸铵溶液和甲醇为流动相，进行梯度洗脱，以电喷雾离子源正负离子切换多反应监测（MRM）模式进行质谱检测。采用内标法定量，进一步降低样品基质效应的影响。结果表明：本方法在去除样品基质干扰方面取得良好效果，9种甜味剂的检出限和定量限分别在2~30 μg/L和6~100 μg/L之间，在各自的线性范围内线性关系良好（相关系数r²>0.999）。9种甜味剂空白样品在3个水平下的加标回收率在86.3%~106.3%之间，相对标准偏差（RSD）在1.2%~5.9%之间。本方法快捷、高效、准确可靠，可用于复杂食品基质中9种人工合成甜味剂的快速检测。     

Simultaneous determination of sweeteners and preservatives in preserved fruits by micellar electrokinetic capillary chromatography

A micellar electrokinetic capillary method for the simultaneous determination of the sweeteners dulcin, aspartame, saccharin, and acesulfame-K and the preservatives sorbic acid; benzoic acid; sodium dehydroacetate; and methyl-, ethyl-, propyl-, isopropyl-, butyl-, and isobutyl-p-hydroxybenzoate in preserved fruits is developed. These additives are ion-paired and extracted using sonication followed by solid-phase extraction from the sample. Separation is achieved using a 57-cm fused-silica capillary with a buffer comprised of 0.05 M sodium deoxycholate, 0.02 M borate-phosphate buffer (pH 8.6), and 5% acetonitrile, and the wavelength for detection is 214 nm. The average recovery rate for all sweeteners and preservatives is approximately 90% with good reproducibility, and the detection limits range from 10 to 25 microg/g. Fifty preserved fruit samples are analyzed for the content of sweeteners and preservatives. The sweeteners found in 28 samples was aspartame (0.17-11.59 g/kg) or saccharin (0.09-5.64 g/kg). Benzoic acid (0.02-1.72 g/kg) and sorbic acid (0.27-1.15 g/kg) were found as preservatives in 29 samples.     

Multi-class determination of antimicrobials in meat by pressurized liquid extraction and liquid chromatography-tandem mass spectrometry

A multi-residue method using pressurized liquid extraction (PLE) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) has been developed for determining trace levels of 31 antimicrobials, including beta-lactams, lincosamides, macrolides, quinolones, sulfonamides, tetracyclines, nitroimidazoles and trimethoprim. The extraction method required pre-homogeneization of the meat with EDTA-washed sand and subsequent one-static-cycle extraction for 10 min with 40 ml of water at 1500 psi and 70 degrees C. The effect of operation temperature, pressure, flush volume, and static cycles on PLE performance was studied. Average recoveries ranged from 75 to 99% with relative standard deviations <18%. The method was validated according to the European Union requirements (2002/657/EC). In addition to the quality parameters included in that decision, the limits of detection (LODs) and quantification (LOQs) were determined. The use of LC-MS/MS provided LODs (between 3 and 15 microg kg(-1)) and LOQs (between 10 and 50 microg kg(-1)), by far lower than half of their maximum residue limits (MRLs) (between 50 and 1200 microg kg(-1)). Confirmation of the presence of any of the studied compounds was accomplished in 1h after sample receipt. This methodology has been successfully applied to the analysis of cattle and pig tissue samples from local markets and slaughterhouses of the Valencian Community (Spain). The results showed the presence of some antimicrobials at different concentrations. Quinolones and tetracyclines were the antimicrobials most detected in cattle and pig samples, respectively. Sulfonamides were also frequently detected in both types of samples.     

Development and validation of a method using on-line solid-phase extraction and liquid chromatography with ultraviolet detection for the determination of bisphenol A, octylphenol, and nonylphenol in groundwater

Alkylphenols are nonbiodegradable metabolites arising from various pathways of aerobic and anaerobic degradation of the nonionic surfactants alkylphenol ethoxylates. A method based on the use of on-line solid-phase extraction (SPE) and liquid chromatography (LC) with UV detection was developed to determine bisphenol A, octylphenol, and nonylphenol at trace levels in water. The on-line coupled SPE procedure automatically enables an approximately 300-fold preconcentration of analytes, which can be further enhanced by an increase in applied sample volume. By using C18 cartridges, recoveries of >90% were obtained for all the analytes. A validation procedure was carried out with a groundwater sample to ensure the quality of the results; performance criteria such as detection limits (LODs), quantitation limits (LOQs), linearity, and precision were evaluated. LODs and LOQs in the range of 0.17-0.36 and 0.35-1.88 microg/L, respectively, were found; for all the analytes, linearity was established over 2 orders of magnitude (r2 >0.997, n = 54). The intraday repeatability values expressed as relative standard deviations were <5.3%; a nested analysis of variance was performed to verify the influence of 3 different factors, i.e., different days, extraction procedure, and LC replicate injection, on data precision.     

Development and validation of a multiresidue method for the analysis of 151 pesticide residues in strawberry by gas chromatography coupled to a triple quadrupole mass analyzer

A new method was developed and validated for the simultaneous determination of 151 pesticide residues in strawberry by gas chromatography coupled to a triple quadrupole mass analyzer (GC/QqQ-MS/MS), mainly using the selected reaction monitoring (SRM) mode. The list of target compounds included various classes of pesticides such as organochlorine (OCPs), organophosphorus (OPPs), carbamates, pyrethroids, triazoles and dicarboximides. A single extraction of 10 g of sample with acetonitrile followed by liquid-liquid partition formed by the addition of 4 g of MgSO4 and 1 g of NaCl was applied in sample preparation. Cleanup of the extracts was carried out by applying dispersive solid-phase extraction (D-SPE) with primary secondary amine (PSA). The analysis time was 21 min. The method was subjected to a thorough validation procedure. The recovery data were obtained by spiking blank samples at two concentration levels (11.5 and 50 microg/kg), yielding recoveries in the range 70-110%. Precision values expressed as relative standard deviation (RSD) were lower than 18% and 22% for the intraday and interday precision, respectively. Linearity was studied in the range 10-200 microg/kg and determination coefficients (R(2)) were higher than 0.98% for all compounds. Limits of detection (LODs) and limits of quantification (LOQs) were established as 4 and 10 microg/kg, respectively. The overall uncertainty of the method was estimated at two different concentrations (11.5 and 50 microg/kg), being lower than 25% in both cases. According to the validation data and performance characteristics as well as the high sample throughput and low cost, the proposed method is suitable for routine application.     

Optimization of a rapid microwave assisted extraction method for the liquid chromatography-electrospray-tandem mass spectrometry determination of isoflavonoid aglycones in soybeans

A very fast chromatographic separation of isoflavonoids genistein, daidzein, formononetin and biochanin A was developed on a C18 high-speed column under isocratic conditions. The method was validated in terms of detection limits, quantitation limits (LOQs), linearity and precision. LOQs in 0.04-0.2 microg/g range were calculated, making feasible the determination of these compounds of nutritional concern at trace levels. Good linearity was demonstrated over three concentration orders of magnitude for each analyte (r2 0.990-1.000). The intra-day and inter-day repeatability was evaluated in terms of relative standard deviation (RSD%) at two concentration levels for each analyte (RSD% <9%). An optimization strategy was adopted to find the best conditions for the extraction of isoflavonoid aglycones from yellow soybeans using microwave-assisted extraction. The most relevant parameters resulted to be the microwave power, the extraction time and the acid concentration, optimal values being 600 W, 1 min and 12 M, respectively. When performing sample treatment on a fortified soybean sample, high recovery percentage was obtained for both compounds (94+/-8% for daidzein and 97+/-5% (n = 4) for genistein). The concentration level at which daidzein and genistein were found in the soybean sample were 1.21+/-0.15 mg/g and 2.38+/-0.09 mg/g (n=4), respectively.     

固相微萃取-气相色谱法和气相色谱-质谱法测定茶叶中氟虫腈及其代谢物残留

基于固相微萃取-气相色谱(SPME-GC)建立了检测茶叶中氟虫腈及其代谢物(脱亚硫酰基氟虫腈、硫化氟虫腈、氟虫腈砜、酰胺氟虫腈)残留的分析方法。实验中采用85 μm聚丙烯酸酯(PA)萃取头,萃取温度为60 ℃,萃取缓冲体系的pH值为9。当添加水平为2～10 μg/kg时,回收率在71.2%～109.3%之间,相对标准偏差(RSD)在1.2%～7.1%之间。方法的检出限(LOD)和定量限(LOQ)分别在0.3～1.2 μg/kg和1.0～4.0 μg/kg之间。对所建立的方法采用气相色谱-质谱(GC-MS)进行确证,结果令人满意。本方法灵敏度、精密度和LOD均符合残留分析要求,具有快速、灵敏度高的特点,适合于茶叶中氟虫腈及其代谢物残留的痕量分析。     

Determination of chlorobenzenes in water by drop-based liquid-phase microextraction and gas chromatography-electron capture detection

A drop-based liquid phase microextraction and gas chromatographic-electron capture detection (GC-ECD) method was described for the determination of chlorobenzenes including chlorobenzene, 1,2-dichlorobenzene, 1,3-dichlorobenzene, 1,4-dichlorobenzene and 1,2,3-trichlorobenzene in 5 ml of water. The method used 2 microl of n-hexane as extraction solvent, 5 min extraction time, a stirring rate of 600 rpm and sample ionic strength of 3 M maintained with sodium chloride at 25 degrees C (ambient temperature). The limits of detection (LODs) ranged from 0.004 microg l(-1) (for 1,3-dichlorobenzene) to 0.008 microg l(-1) (for monochlorobenzene). The dynamic linear range for all investigated chlorobenzenes was 1-50 microg l(-1). Recoveries of chlorobenzenes from fortified distilled water are over 90% for three different fortification levels (5, 15 and 45 microg l(-1)) and relative standard deviations of the recoveries are below 6%. Analysis of fortified (5 microg l(-1)) real water samples revealed that matrices had no adverse effect on extraction efficiency of proposed method. The recovery of fortified real water samples was from 90 to 94% with relative standard deviations below 6%.     

Evaluation of different sample treatments for determining pesticide residues in fat vegetable matrices like avocado by low-pressure gas chromatography-tandem mass spectrometry

A multi-residue method has been developed for determining 65 pesticide residues in greasy vegetable matrices such as avocado. Conventional organic solvent extraction assisted by a high-speed homogenizer was compared to pressurized liquid extraction (PLE) as extraction techniques. Following this, the lipophilic extract was purified using gel permeation chromatography (GPC). Alternative clean-up methods were also evaluated, as solid-phase extraction cartridges individually used and downstream coupled, but less effective lipophilic separation was archived. The pesticide residue determination was carried out using low-pressure gas chromatography coupled to tandem mass spectrometry (LP-GC-MS-MS), showing the applicability of this type of GC columns for the analysis of fat vegetable matrices. The proposed methodology was validated in avocado matrix. The recoveries were in the range 70-110%, with RSD values lower than 19%, at 12 and 50 microg/kg spiking levels. The limits of quantitation (LOQs) were in the range 0.04-8.33 microg/kg and the limits of detection (LODs) were between 0.01 and 2.50 microg/kg. All of them were lower than the maximum residue levels (MRLs) set by the European Union (EU) in avocado. The proposed method was evaluated analyzing pesticide residues in real avocado samples.     

液相色谱-串联质谱法快速筛查马饲料中39种违禁药物

建立了同时快速筛查和确证马饲料中39种赛马违禁药物(包含抗心率失常类药物、抗惊厥类药物、止痉挛类药物、抗疟疾类药物、刺激剂、麻醉剂及大麻酚类药物)的液相色谱串联质谱(HPLC-MS/MS)分析方法。样品粉碎后分别经1 mmol/L HClO4溶液和酸化乙腈溶液提取,并通过混合型固相萃取柱净化。采用Agilent Zorbax SB(10.0 cm×2.1 mm i.d.,3.5 μm) 色谱柱,以0.4%甲酸水溶液和0.4%甲酸乙腈为流动相进行梯度洗脱,正离子多反应监测(MRM) 模式下检测。方法对空白饲料3个加标水平下的平均回收率为58%~116%,相对标准偏差为1.6%~20.4%,各类药物线性良好(r2＞0.99)。方法检出限(S/N≥3)和定量下限(S/N≥10)分别为0.2~25.0 μg/kg和1.0~40.0 μg/kg,其中超过67%药物的检出限在2.5 μg/kg以下。实验结果表明,该方法分析时间短,灵敏度、精密度良好,适用于马饲料中上述几类药物的快速筛查和测定。     

Lab-on-valve for the automatic determination of the total content and individual profiles of linear alkylbenzene sulfonates in water samples

Methods for the total content and individual determination of linear alkylbenzene sulfonates (LAS) in water samples based on the use of a lab-on-valve (LOV) module alone or coupled to CE equipment, respectively, have been developed. The total content of LAS has been determined by intrinsic absorption measurements (DA method) and after reaction with a methyl orange-cetylpyridine chloride mixture (MO method) with detection limits (LODs) of 21 ng/L and 15 microg/L, respectively, quantification limits (LOQs) of 70 ng/L, 50 microg/L, and development times of 100 and 124 s, respectively. The method for individual separation-quantification of LAS at very low concentration is based on automatic SPE preconcentration in the LOV module coupled on-line with the CE equipment. The LODs and LOQs thus obtained range between 1-21 and 4-70 ng/L, respectively, with linear dynamic ranges from the LOQ to 10 microg/L. Preconcentration factors of 10,000 and high efficiency to eliminate interferents by SPE enable application of the method to treated effluent, waste, surface and sea waters.     

气相色谱-串联质谱法测定茶叶中88种农药残留量

采用气相色谱-串联质谱(GC-MS/MS)分析技术,建立了高灵敏度检测茶叶中88种农药残留量的方法。目标化合物经加速溶剂萃取(ASE), Carb/NH2净化小柱净化,乙腈-甲苯(3:1, v/v)洗脱,采用GC-MS/MS测定。对方法的准确性、精密度、线性范围、最低检出限(LOD)和定量限(LOQ)进行了测试。其中87.5%的农药在低水平(6.4 μg/kg)的加标回收率为70%～100%; 87.5%的农药的相对标准偏差(RSD)小于15%。每个化合物均采用灵敏度最高的离子对进行定量,并采用空白茶叶基质配制标准工作液。LOQ以10倍信噪比(S/N=10)计算,86.4%农药的LOQ值低于10 μg/kg。该方法灵敏度高、准确、可靠,适用于绿茶、乌龙茶、红茶以及普洱茶中多种农药残留量的检测。     

固相萃取-高效液相色谱-蒸发光散射检测法同时检测食品中5种人工合成甜味剂

建立了高效液相色谱-蒸发光散射检测仪(HPLC-ELSD)同时检测食品中安赛蜜、糖精钠、甜蜜素、三氯蔗糖和阿斯巴甜5种甜味剂的方法。甜味剂经0.1%(v/v)甲酸缓冲液提取后,利用C18固相萃取小柱净化浓缩,以3 μm C18柱为分离柱,0.1%(v/v)甲酸(氨水调节pH=3.5)-甲醇(61:39, v/v)为流动相,经高效液相色谱法分离,蒸发光散射检测器进行检测。结果表明,5种甜味剂在30～1000 mg/L的范围内,具有良好的线性关系(相关系数大于0.997);在3个添加水平下,样品的平均回收率为85.6%～109.0%,相对标准偏差小于4.0%;方法检出限(LOD,信噪比(S/N)=3)分别为安赛蜜2.5 mg/L、糖精钠3 mg/L、甜蜜素10 mg/L、三氯蔗糖2.5 mg/L及阿斯巴甜5 mg/L。该方法简单、灵敏、操作成本低,可用于不同形态食品中多种甜味剂的同时检测。     

Application of gas chromatography-triple quadrupole mass spectrometry in the quantification-confirmation of pesticides and polychlorinated biphenyls in eggs at trace levels

A new multiresidue method has been developed and validated for the simultaneous analysis of 57 compounds, including organochlorine and organophosphorus pesticide residues (OCPs and OPPs) and polychlorinated biphenyls (PCBs), in eggs at trace levels by gas chromatography coupled to triple quadrupole mass spectrometry (GC-QqQ-MS/MS). Egg samples were extracted by a simple and fast matrix solid phase dispersion (MSPD) procedure using C18 as sorbent, and ethyl acetate and acetonitrile saturated in n-hexane (85:15, v/v) as elution solvent with a simultaneous clean up with Florisil in-line. The QqQ analyzer acquired data in selected reaction monitoring (SRM) mode, permitting both quantification and confirmation in a single injection with a running time reduced up to 17.70 min. Recovery was in the range of 70-110% and 70-106% at 15 and 50 microg/kg, respectively. Precision values expressed as relative standard deviation (RSD) were lower than 20%. Linearity in the range of 10-150 microg/kg provided determination coefficients (R(2)) higher than 0.98 for all compounds. Limits of detection (LODs) for pesticides were < or =2.25 microg/kg and limits of quantification (LOQs) ranged from 0.02 to 7.78 microg/kg. LODs for PCBs were < or =0.41 microg/kg and LOQ were < or =0.71 microg/kg. The method was applied to real samples. Endosulfan sulphate and p,p'-DDE were found in two samples at concentrations below the first calibration level.     

Determination of musk fragrances in sewage sludge by pressurized liquid extraction coupled to automated ionic liquid‐based headspace single‐drop microextraction followed by GC‐MS/MS

A method for the quantitative determination of ten musk fragrances extensively used in personal care products from sewage sludge was developed by using a pressurized liquid extraction (PLE) followed by an automated ionic liquid‐based headspace single‐drop microextraction and gas chromatography‐tandem mass spectrometry. The influence of main factors on the efficiency of PLE was studied. For all musks, the highest recovery values were achieved using 1 g of pretreated sewage sludge, H₂O/methanol (1:1) as an extraction solvent, a temperature of 80°C, a pressure of 1500 psi, an extraction time of 5 min, 2 cycles, a 100% flush volume, a purge time of 120 s, and 1 g Florisil as in‐cell clean‐up extraction sorbent. The use and optimization of an in‐cell clean‐up sorbent was necessary to remove fatty interferents of the PLE extract that make the subsequent ionic liquid‐based headspace single‐drop microextraction difficult. Validation parameters, namely LODs and LOQs, ranged from 0.5–1.5 to 2.5–5 ng/g, respectively. Good levels of intra‐ and interday repeatabilities were obtained analyzing sewage sludge samples spiked at 10 ng/g (n = 3, RSDs < 10%). The method applicability was tested with sewage sludge from different wastewater treatment plants. The analysis revealed the presence of all the polycyclic musks studied at concentrations higher than the LOQs, ranging from 6 to 530 ng/g. However, the nitro musk concentrations were below the LOQs or, in the case of musk xylene, was not detected.     

Comparison between charged aerosol detection and light scattering detection for the analysis of Leishmania membrane phospholipids

The performance of charged aerosol detection (CAD) was compared to evaporative light scattering detection (ELSD) for the analysis of Leishmania membrane phospholipid (PL) classes by NP-HPLC. In both methods, a PVA-Sil column was used for the determination of the major Leishmania membrane PLs, phosphatidic acid, phosphatidylglycerol, cardiolipin, phosphatidylinositol, phosphatidylethathanolamine, phosphatidylserine, lysophosphatidylethathanolamine, phosphatidylcholine, sphingomyelin and lysophosphatidylcholine in the same analysis. Although the response of both detection methods can be fitted to a power function, CAD response can also be described by a linear model with determination coefficients (R(2)) ranging from 0.993 to 0.998 for an injected mass of 30 ng to 20.00 microg. CAD appeared to be directly proportional when a restricted range was used and it was found to be more sensitive at lowest mass range than ELSD. With HPLC-ELSD the limits of detection (LODs) were between 71 and 1195 ng and the limits of quantification (LOQs) were between 215 and 3622 ng. With HPLC-CAD, the LODs were between 15 and 249 ng whereas the limits of quantification (LOQs) were between 45 and 707 ng. The accuracy of the methods ranged from 62.8 to 115.8% and from 58.4 to 110.5% for ELSD and CAD, respectively. The HPLC-CAD method is suitable to assess the influence of miltefosine on the composition of Leishmania membrane phospholipids.     

超高效液相色谱-电喷雾三重四极杆质谱法测定中药中马兜铃酸A和B的含量

利用超高效液相色谱-电喷雾三重四极杆质谱仪建立了中药中马兜铃酸A和B的定性定量分析方法。选取柴胡、生甘草、桔梗、龙胆泻肝丸、消胖丸、减肥茶等14种代表性样品,用甲醇-水(70:30, v/v)溶液加热回流提取,经Oasis MAX固相萃取柱富集净化后,在Eclipse RP HD C18反相柱(150 mm×2.1 mm, 1.8 μm)上进行分离;流动相为5 mmol/L乙酸铵水溶液(pH 7.5)-乙腈(75:25, v/v)。采用电喷雾离子源正离子模式(ESI+)和多反应监测模式(MRM)进行质谱分析。马兜铃酸A和B的线性范围分别为0.5～200 μg/L和1～200 μg/L,相关系数(r2)均大于0.995;检出限(LODs)分别为5 μg/kg和7.5 μg/kg;定量限(LOQs)分别为12.5 μg/kg和25 μg/kg。在100 μg/kg和500 μg/kg添加水平下,马兜铃酸A和B的回收率(n=6)范围分别为60.3%～96.4%和61.3%～94.7%,相对标准偏差均不大于10.2%。该方法灵敏度高,重复性好,操作简便,适用于中药材、饮片及中成药中马兜铃酸A和B的痕量检测。     

Atmospheric pressure glow discharge desorption mass spectrometry for rapid screening of pesticides in food

Flowing afterglow atmospheric pressure glow discharge tandem mass spectrometry (APGD-MS/MS) is used for the analysis of trace amounts of pesticides in fruit juices and on fruit peel. The APGD source was rebuilt after Andrade et al. (Andrade et al., Anal. Chem. 2008; 80: 2646-2653; 2654-2663) and mounted onto a hybrid quadrupole time-of-flight mass spectrometer. Apple, cranberry, grape and orange juices as well as fruit peel and salad leafs were spiked with aqueous solutions containing trace amounts of the pesticides alachlor, atrazine, carbendazim, carbofuran, dinoseb, isoproturon, metolachlor, metolcarb, propoxur and simazine. Best limits of determination (LODs) of pesticides in the fruit juices were achieved for metolcarb (1 microg/L in apple juice), carbofuran and dinoseb (2 microg/L in apple juice); for the analysis of apple skin best LODs were 10 pg/cm(2) of atrazine, metolcarb and propoxur which corresponds to an estimated concentration of 0.01 microg/kg apple, taking into account the surface area and the weight of the apple. The measured LODs were within or below the allowed maximum residue levels (MRLs) decreed by the European Union (1-500 microg/kg for pesticides in fruit juice and 0.01-5 microg/kg for apple skin). No sample pretreatment (extraction, pre-concentration, chromatographic separation) was necessary to analyze these pesticides by direct desorption/ionization using APGD-MS and to identify them using MS/MS. This makes APGD-MS a powerful high-throughput tool for the investigation of very low amounts of pesticides in fruit juices and on fruit peel/vegetable skin. Copyright (c) 2008 John Wiley & Sons, Ltd.     

磁固相萃取-液相色谱法测定环境水样中有机紫外防晒剂

采用自制的聚离子液体功能化磁性材料有效富集有机紫外防晒剂，并与高效液相色谱-二极管阵列检测器（HPLC-DAD）联用，建立了环境水样中痕量有机紫外防晒剂的检测方法。研究系统考察了解吸溶剂、吸附和解吸时间、样品pH值、离子强度等因素对萃取性能的影响。在最佳萃取条件下，水杨酸辛酯的线性范围为0.5~200.0 μg/L，其他有机紫外防晒剂的线性范围为0.2~200.0 μg/L；6种目标物的检出限（LOD，S/N=3）和定量限（LOQ，S/N=10）分别为0.009~0.13 μg/L和0.031~0.43 μg/L。所建方法成功用于实际环境水样中有机紫外防晒剂的测定，不同加标水平下目标物的加标回收率为71.4%~120%，相对标准偏差均低于10%。研究表明，所建方法具有操作简便、萃取速度快、灵敏度高和环境友好等特点，可用于环境水样中有机紫外防晒剂的检测。     

Simultaneous determination of seven alkaloids in Phellodendron chinense Schneid by high-performance liquid chromatography

By optimizing the extraction, separation, and analytical conditions, a reliable and accurate HPLC method coupled with a photodiode array detector was developed for simultaneous detection and quantification of seven alkaloids, i.e., (-)-(R)-platydesmin, noroxyhydrastinine, berberine, skimmianine, canthin-6-one, chilenine, and pteleine in "huangbo" (the bark of Phellodendron chinense), a commonly used herb in Traditional Chinese Medicine. The optimal condition for separation was achieved on a reversed-phase Cis column with a stepwise mobile phase gradient prepared from 0.1% phosphoric acid and acetonitrile. For all the alkaloids, a good linear regression relationship (r > 0.9997) was obtained between the peak area and concentration at the range of 0.5-700 microg/mL. The LODs and LOQs for the analytes ranged from 0.07 to 0.28 microg/mL and from 0.28 to 1.12 microg/mL, respectively. The optimized method was applied to the determination of alkaloids in several P. chinense samples, and found to be feasible and reliable. This method and quantitative results can provide scientific and technical bases for setting up QC standards to assure the safety and quality of P. chinense bark raw material, as well as for proprietary Chinese medicine products containing P. chinense bark.