固相萃取-高效液相色谱法测定沙苑子苷含量

目的：建立沙苑子总黄酮中沙苑子苷的含量测定方法。方法：用以氨基为固定相的固相萃取柱对沙苑子总黄酮进行纯化,洗去杂质后的洗脱液进高效液相色谱仪测定。色谱柱为VP—ODS（150mm×4．6mm,5um）,流动相为甲醇：1％HAC溶液（41：59）;流速1．2mL／min;检测波长266nm。结果：沙苑子苷在5—25μg／mL范围内呈良好的线性关系,加样回收率为102．5％,RSD2．3％。结论：本法灵敏、快速、准确,可用于测定沙苑子总黄酮中沙苑子苷的含量。     

以沙苑子苷为对照品测定沙苑子总黄酮含量

目的 :以沙苑子苷为对照品测定沙苑子总黄酮含量。方法 :80 %乙醇提取液 ,2 6 6nm测定紫外吸收度。结果 :总黄酮含量为 2 1.5mg/g ,RSD =1.0 0 % ;回收率 95 .4 % ,RSD =2 .2 7% ,线性范围 4～ 2 4ug/ml。结论 :本法测定沙苑子总黄酮含量 ,操作简便 ,稳定性好 ,可用于沙苑子的质量控制。     

反相C18固相萃取小柱用于蛋白质组分析中少量样品预处理

针对少量且复杂蛋白质组样品,开发一种耗时短、操作简便的分离方法。以人的脑海马组织蛋白样品为研究对象,采用反相C18固相萃取小柱,采用不同乙腈浓度对酶切后样品进行梯度洗脱,与反相高效液相色谱法对比分离效果。通过比较不同乙腈梯度洗脱方案所鉴定到的谱图数、非冗余多肽数、蛋白数和各洗脱组分间重复率分析,确定一种样品量少、简单易行、分离效果好的实验方案。虽然反相C18固相萃取小柱法鉴定蛋白总数占高效液相色谱法的85.5%,但其操作简单,耗时少。通过4种不同乙腈浓度方案比较,确定乙腈洗脱浓度优化为5%、15%、20%和90%时,分离30μg人的海马多肽混合物可以得到较优的分离效果。其蛋白鉴定数为反相液相色谱法的67.0%,且重复性良好。该结果证实反相C18固相萃取小柱分离效果比反相高效液相色谱法稍差,但此方法可以分离少量复杂蛋白质组样品。该方法分离样品充分,操作易行,耗时短,是进行蛋白质组学分析中少量样品的一个简便预处理方法。     

SPE-HPLC法快速检测发酵液中紫杉醇的含量

针对红豆杉内生真菌发酵液中紫杉醇的含量测定进行探讨,以建立快速高效低耗的检测方法.采用C_(18)固相萃取柱对紫杉醇进行吸附,用不同浓度的甲醇-乙酸铵和甲醇分别作为洗脱剂对其进行洗脱,比较两者的洗脱效果,洗脱液用HPLC进行检测;色谱条件为:流动相甲醇(v):水(v):乙腈(v)=20: 45: 35,流速:0.70 ml/min,检测波长:227 nm.结果表明,浓度为80%的甲醇溶液洗脱效果较好,紫杉醇的回收率为87.6%.     

固相萃取-反相高效液相色谱法分析粗裂地钱中的黄酮类化合物

建立了粗裂地钱中四种黄酮类化合物的固相萃取高效液相色谱分析方法。样品经95%乙醇溶液提取后,用C18固相萃取小柱预处理,采用甲醇∶乙腈∶0.5%乙酸(150∶100∶150,V/V)为流动相,C18色谱柱(150 mm×4.6 mm,5μm)进行分离与测定。低、中、高浓度下方法的回收率为89.70%～97.95%,RSD小于6%。结果表明,该法简便快速,节省溶剂,分析结果准确可靠,重复性好,可用于粗裂地钱中四种黄酮类化合物的含量分析。     

HPLC梯度洗脱同时测定牛蒡子液体制剂中牛蒡子苷和牛蒡子苷元的含量

目的:建立一种同时测定牛蒡子液体制剂中牛蒡子苷和牛蒡子苷元含量的HPLC梯度洗脱法。方法:采用Dionex Summit高效液相色谱系统,ODS C18柱(4.6mm×250 mm,5μm),乙腈-水为流动相梯度洗脱,流速1.0ml/min,测定波长280nm,柱温30℃下对牛蒡子液体制剂中牛蒡子苷和牛蒡子苷元进行含量测定。结果:牛蒡子苷进样浓度在0.098～0.98mg/ml、牛蒡子苷元进样浓度在0.0304～0.304mg/ml范围内线性关系良好(r=0.9997、r=0.9995),平均回收率分别为100.80%,RSD为1.9%(n=6)和98.6%,RSD为2.3%(n=6)。结论:该方法准确可靠、重现性好,可用于牛蒡子液体制剂的含量测定。     

泽漆总黄酮的制备工艺及神经保护活性

以总黄酮和金丝桃苷为考察指标,通过静、动态吸附和解析实验,对三种阴离子交换树脂和三种大孔吸附树脂进行筛选,确定制备泽漆总黄酮的工艺。优选FPA98阴离子交换树脂制备泽漆总黄酮,提取液与树脂的比例100∶1(v/w),以pH 2的70%甲醇洗脱。FPA98树脂吸附总黄酮的效率为47.86 mg/g,总黄酮解析率为88.7%。产品中总黄酮和金丝桃苷含量分别为48.3%和10.3%。进一步纯化后的泽漆总黄酮对鱼藤酮诱导的神经细胞损伤有较好的保护作用。     

HPLC 法测定不同来源槐角中槐角苷含量

目的:建立HPLC法测定槐角中槐角苷含量测定方法并检测不同来源槐角中槐角苷的含量。方法:Luna 5u C18(2)100A柱(250 mm×4.60 mm,5μm),柱温为35℃,流动相为甲醇-乙腈-1%冰醋酸(40:5:55),流速为1.0 ml/min,检测波长为260 nm。结果:槐角苷质量浓度在14.58 mg/L～53.46 mg/L范围内呈良好的线性关系,回归方程为y=110353x-274717(r=0.9999),平均回收率为99.5%,RSD为1.27%;不同来源槐角中槐角苷含量范围4.27%～8.78%。结论:该方法简便、快速、灵敏、可靠;不同来源的槐角中槐角苷含量有较大差异,其中以陕北黄土高原品种含量最高,可为槐角的质量保证提供依据。     

固相萃取-高效液相色谱法测定复合薯片中丙烯酰胺

建立了一种利用固相萃取小柱与高效液相色谱联用,采用光电二极管阵列检测器测定复合薯片中丙烯酰胺的方法。以0．1％的甲酸水溶液为提取试剂,采用Waters Oasis HLB固相萃取小柱（200mg／6cc）对提取液净化处理,然后以流动相为甲醇／水（5：95,V：V）,流速为0．6mL／min,检测波长为210nm,利用AgilentC18反相色谱柱进样分析。在该条件下丙烯酰胺的回收率达80％以上,最低检测限小于10ng／mL。该方法操作简便、重复性好、稳定性高,可用于油炸复合薯片中丙烯酰胺的快速检测。     

魔芋中神经酰胺类物质的HPLC-ELSD分析及其含量测定

建立高效液相色谱-蒸发光散射检测器分析神经酰胺的方法并进行了含量的测定.色谱柱:ZORBZX Eclipse XDB-C18(4.6mm×250mm,5μm),洗脱方法:梯度洗脱,柱温:35℃,流动相:甲醇/水,流速:1ml/min;检测器:蒸发光散射检测器,漂移管温度:40℃,氮气流速:1.5L/min.系统探讨了梯度洗脱的起始浓度、洗脱的时间和洗脱梯度的程序设置,最佳的梯度洗脱条件为5min内,甲醇浓度从60%线性增加为90%,从5min到25min,甲醇浓度线性增加为95%,在此条件下样品和标准品的分离色谱峰对称性较好.随后测定了各种样品中神经酰胺的含量,并进行了方法学验证,结果神经酰胺在0.2～2μg之间线性关系良好,最低检测限为0.01mg/ml,R2=0.9992;平均回收率为93.3%,RSD=1.65%(n=5).本法灵敏、方便、准确,重现性好,可用于魔芋神经酰胺类物质的分离及其含量的测定.     

气相色谱-质谱法测定中药沙苑子中的氨基酸

本文利用气相色谱一质谱(GC/MS)联用技术首次对中药沙苑子中的氨基酸进行了定性定量分析。沙苑子经盐酸水解后,对其氨基酸水解液进行羟基脂化和氨基酰化的衍生化反应,利用GC/MS法共测得15种氨基酸,由外标法测定了每种氨基酸的含量。由此得出沙苑子中氨基酸的总质量分数为4.23％。     

SPE-GC-MS for the sampling and determination of unmetabolized styrene in urine

The urinary excretion of unmetabolized styrene can be a very good indicator for biomonitoring styrene in occupationally exposed people. The use of a new urine sampling system, involving a solid-phase extraction cartridge, offers several advantages for determining styrene. The advantages are especially related to the pre-analytical phase of styrene determination, which may be influenced by many variables. The effect on styrene recovery of sorbent type, eluting solvent, elution volume, elution flow-rate, and the addition of methanol to the washing solvent, was evaluated by experimental design methodology. As a result, Oasis HLB cartridges were selected for urine sampling, as well as 1.5 mL of ethyl acetate at 0.5 mL/min for eluting the retained styrene. These conditions were then applied to the validation of the solid-phase extraction combined with GC-MS method for the sampling and analysis of unmetabolized styrene in urine. The overall uncertainty was in the 12-22% range and the limit of detection was 2.2 microg/L for a 4 mL urine sample. The stability of styrene has been studied both in cartridges and in vials under different storage periods. After 1 month period the styrene stored on cartridges at room temperature remained stable, whereas this is not the case for styrene recovery from vials. The results obtained indicate that on-site solid-phase extraction of urine can provide a simple, accurate and reproducible sampling and analytical method for the biomonitoring of styrene in urine.     

Determination of 4-amino-m-cresol and 5-amino-o-cresol by high performance liquid chromatography and fluorescence derivatization using fluorescamine

For the determination of two oxidation hair dyes, 4-amino-m-cresol (4-AC) and 5-amino-o-cresol (5-AC), a sensitive isocratic high performance liquid chromatography (HPLC) method using the reversed phase mode was developed. The hair dyes were pre-column derivatized with fluorescamine prior to injection. Sensitivity could be improved 10-fold for 4-AC and 50-fold for 5-AC by fluorescence detection compared to UV detection. The limit of detection was 1 ng/injection for 4-AC and 100 pg/injection for 5-AC, respectively. For the determination of both compounds in aqueous biological matrices in order to simulate conditions for penetration studies with pig skin, a solid phase extraction procedure using C18 cartridges and acetonitrile (ACN) for elution could be developed. Average recovery was 83.4% with a coefficient of variation (CV) of 2.64% for intra-day assay and 3.20% for inter-day assay for 5-AC and 2.89% and 3.41% for 4-AC, respectively.     

An evaluation of the use of Sep-Pak C18 cartridges for the extraction of vitamin D3 and some of its metabolites from plasma and urine

The use of Sep-Pak C18 cartridges for the extraction of vitamin D and some of its metabolites from plasma and urine has been evaluated by studying the recovery of added tritiated secosteroids. The preparation of the cartridges, recoveries, extraction and elution with a number of solvents, effect of varying flow rates for application and elution, and the effect of increasing volumes of plasma and urine have been investigated. Two methods for the application of secosteroids present in plasma to Sep-Pak C18 cartridges have been examined, using methyl cyanide extracts removing precipitated protein by centrifugation, and using acidified methanolic plasma. Methyl cyanide extracts applied to Sep-Pak C18 cartridges and eluted with methanol or methyl cyanide gave the cleanest extracts suitable for direct HPLC. Acidified methanolic plasma, applied to Sep-Pak C18 cartridges and eluted with methanol or methyl cyanide gave extracts which could not be applied directly to an HPLC--further fractionation using Sep-Pak SIL cartridges was necessary. Recoveries of added tritiated secosteroids using both methods were greater than 80% with the exception of vitamin D itself which was poorly recovered--methyl cyanide extraction giving only 30% recovery and use of acidified methanolic plasma giving 66% recovery.     

Rapid determination of sixteen sulfonylurea herbicides in surface water by solid phase extraction cleanup and ultra-high-pressure liquid chromatography coupled with tandem mass spectrometry

A sensitive and very fast analytical method has been developed for the simultaneous quantification of sixteen sulfonylurea herbicides in surface water. An ultra-high-pressure liquid chromatography coupled with tandem mass spectrometry method with solid phase extraction for sample cleanup has been developed for screening sixteen sulfonylurea herbicides (oxasulfuron, thifensulfuron-methyl, cinosulfuron, metsulfuron methyl, sulfometuron methyl, triasulfuron, rimsulfuron, ethametsulfuron methyl, sulfosulfuron, tribenuron methyl, bensulfuron methyl, iodosulfuron methyl, pyrazosulfuron ethyl, prosulfuron, chlorimuron ethyl, ethoxysulfuron) in water samples simultaneously within 12 min. Water samples were acidified, and the target herbicides were extracted by passing through ProElut C18 extraction cartridges. After drying by nitrogen flow, the cartridges were eluted with elution solvents, and the eluate was then evaporated to dryness, redissolved and analyzed. The mobile phase composed of 0.02% formic acid and acetonitrile using gradient elution. A triple quadrupole mass spectrometer equipped with an electrospray ionization source operated in the positive ion with selective reaction monitoring mode. Each of the analytes in all the samples was monitored using protonated molecule and its two characteristic fragment ions for confirmation. The limits of detection for all analytes were below 1.0 ng/mL, except for sulfosulfuron and prosulfuron, and limits of quantitation were between 1 and 8 ng/mL for this method. Three water types were used for the validation of the method.     

Simultaneous Enantiomeric Determination of Propranolol,Metoprolol, Pindolol,and Atenolol in Natural Waters by HPLC on New Polysaccharide‐Based Stationary Phase using a Highly Selective Molecularly Imprinted Polymer Extraction

A simple high performance liquid chromatography method HPLC‐UV for simultaneous enantiomeric determination of propranolol, metoprolol, pindolol, and atenolol in natural water samples was developed and validated, using a molecularly imprinted polymer solid‐phase extraction. To achieve this purpose, Lux® Cellulose‐1/Sepapak‐1 (cellulose tris‐(3,5‐dymethylphenylcarbamate)) (Phenomenex, Madrid, Spain) chiral stationary phase was used in gradient elution and normal phase mode at ambient temperature. The gradient elution program optimized consisted of a progressive change of the mobile phase polarity from n‐hex/EtOH/DEA 90/10/0.5 (v/v/v) to 60/40/0.5 (v/v/v) in 13 min, delivered at a flow rate of 1.3 ml/min and a sudden change of flow rate to 2.3 ml/min in 1 min. Critical steps in any molecularly imprinted polymer extraction protocol such as the flow rate to load the water sample in the cartridges and the breakthrough volume were optimized to obtain the higher extraction recoveries for all compounds. In optimal conditions (100 ml breakthrough volume loaded at 2.0 ml/min), extraction recoveries for the four pairs of β‐blockers were near 100%. The MIP‐SPE‐HPLC‐UV method developed demonstrates good linearity (R² ≥ 0.99), precision, selectivity, and sensitivity. Method limit detection was 3.0 µg/l for propranolol and pindolol enantiomers and 20.0 and 22.0 µg/l for metoprolol and atenolol enantiomers, respectively. The proposed methodology should be suitable for routine control of these emerging pollutants in natural waters for a better understanding of the environmental impact and fate. Chirality 24:860–866, 2012. © 2012 Wiley Periodicals, Inc.     

HPLC analysis of the second-generation antidepressant sertraline and its main metabolite N-desmethylsertraline in human plasma

A liquid chromatographic method with ultraviolet detection was developed for the analysis of the recent antidepressant sertraline and its main metabolite N-desmethylsertraline in human plasma. The analytes were separated on a C8 reversed phase column, using a mobile phase composed of acetonitrile and a 12.3 mM, pH 3.0 phosphate buffer containing 0.1% triethylamine (35:65, v/v). Clomipramine was used as the Internal Standard. Using a solid phase extraction procedure with C2 cartridges high extraction yields (>94%) and good purification from matrix interference were obtained. Good linearity was obtained in the 7.5-250.0 ng mL(-1) range for sertraline and in the 10-500 ng mL(-1) range for N-desmethylsertraline. The analytical method was validated in terms of precision, extraction yield and accuracy. These assays gave R.S.D.% values for precision always lower than 3.9% and mean accuracy higher than 90%. Thanks to its good selectivity, the method proved to be suitable for the analysis of plasma samples from patients treated with sertraline as either monotherapy or polypharmacy.     

A novel solid‐phase extraction–spectrofluorimetric method for the direct determination of atenolol in human urine

A novel, simple, sensitive and selective solid‐phase extraction (SPE)–spectrofluorimetric method has been developed for the determination of atenolol (ATE) in human urine. Because an extraction procedure is required to isolate ATE or eliminate the interfering molecules present in complex human urine for the direct spectrofluorimetric determination, a pH‐sensitive poly(acrylic acid‐ethylene glycol dimethacrylate) [poly(AA‐EGDMA)] hydrogel was developed and used as a SPE adsorbent. Some factors affecting the ATE extraction efficiency, such as washing solvent type and volume, and the volume of elution solvent were optimized. Eluates from SPE cartridges were analyzed using a spectrofluorimeter (λ_ex = 277 nm and λ_em = 300 nm). The calibration graph was linear over the concentration range 0.15–4.0 µg/mL. Limit of detection (LOD) and limit of quantification (LOQ) values were found to be 0.03 and 0.10 µg/mL, respectively. Relatively high intraday [2.06%, mean relative standard deviation (RSD)] and interday (2.6%, mean RSD) precisions were achieved. High mean recovery (95.4%) and low RSD values (3.8%) were obtained for spiked ATE in human urine. The spectrofluorimetric method presented here can be easily applied to assay trace amounts of ATE in pharmaceuticals and biological samples. Copyright © 2013 John Wiley & Sons, Ltd.     

Analysis of phenolic acids in honeys of different floral origin by solid-phase extraction and high-performance liquid chromatography

The determination of 18 aromatic and arylaliphatic carboxylic acids in honey from different floral origin using solid-phase extraction (SPE) and reversed-phase high performance liquid chromatography (RP-HPLC) is reported. The behaviour of the solutes on SPE cartridges was predicted from preliminary calculations involving the pK(a) constants of the carboxylic groups, the n-octanol:water partition coefficients and the distribution coefficients at different pH values of the conditioning and washing solvents. The proposed SPE isolation and pre-concentration of the acids was achieved on reversed-phase Bond Elut C18 cartridges using an acetonitrile:tetrahydrofuran (1:1, v/v) elution system. RP-HPLC separations were performed on a Spherisorb ODS-2 column using linear gradient elution with a mobile phase composed of 20 mm phosphate buffer (pH 2.92) and methanol, and with UV detection. The reported SPE and RP-HPLC methods were applied to the analysis of 49 authentic honey samples from various floral sources and the results indicate that they may serve with respect to the quantitative control of a number of phenolic acids in plant-derived foods and medicinal plants.