Determination of 5-Fluorouracil in Human Plasma by High-Performance Liquid Chromatography (HPLC)

5-Fluorouracil (5-FU) has a broad spectrum of anti-tumor activity, widely applied to the treatment of cancers. However, it is necessary to determine the plasma concentration of 5-FU in clinical practice due to its narrow therapeutic index. Therefore, a simple, economic and sensitive high-performance liquid chromatography (HPLC) method was developed and validated for the determination of 5-FU in human plasma. Ethyl acetate was chosen as extraction reagent. Chromatographic separation was performed on a Diamonsil C18 column (250 mm × 4.6 mm i.d., 5 μm) with the mobile phase consisting of methanol and 20 mmol/L ammonium formate using a linear gradient elution at a flow rate of 0.8 mL/min. 5-FU and 5-bromouracil (5-BU) were detected by UV detector at 265 nm. The calibration curve was linear over the concentration range of 5—500 ng/mL and the correlation coefficient was not less than 0.992 6 for all calibration curves. The intra- and inter-day precisions were less than 10.5% and 4.3%, respectively, and the accuracy was within ±3.7%. The recovery at all concentration levels was 80.1±8.6%. 5-FU was stable under possible conditions of storing and handling. This method is proved applicable to therapeutic drug monitoring and pharmacokinetic studies of 5-FU in human.

Simultaneous determination of five nucleosides and nucleobases in Panax notoginseng using high-performance liquid chromatography

Aim To quantitatively determine five nucleosides and nucleobases, including cytidine, uridine, guanosine, adenosine and uracil in different parts of Panax notoginseng. Methods Separation was performed on a Zorbax SB-Aq column using a gradient elution with mobile phase of 8 mmol^L-1 ammonium acetate aqueous solution （A） and methanol （B）. The assay was carried out at a flow rate of 1 mL·min^-1 at 25 ℃ with the diode-array detection at 260 nm. Results Cytidine, uridine, guanosine, adenosine and uracil had good linearity in the ranges of 1.79 - 57.40 μg·mL^-1 （r^2 = 1.0000）, 3.30 - 105.60 μg·mL^-1 （r^2 = 1.0000）, 3.09 - 98.80 μg·mL^ -1（r^2 = 0.9999）, 2.77 - 88.60 μg·mL^-1 （r^2 = 1.0000） and 0.38 - 12.30 μg·mL ^-1 （r^2 = 1.0000） with average recoveries of 93.9%, 96.5%, 92.7%, 93.2% and 98.8%, respectively. The content of cytidine, uridine, guanosine, adenosine and uracil in different parts of P. notogingeng were significantly different. Conclusion This is the first report on quantitative determination of nucleosides and nucleobases in P notoginseng.

High-Performance Liquid Chromatographical Analysis of Ginsenosides in Panax ginseng,P.quinquef(?)lium and P.notoginseng

The compositions and contents of ginsenbsides in Panax ginseng,P.quinquefolium and P.notoginseng were determined and compared by reversed-phase High-Performance Liquid Chro- matography(HPLC).The method was performed on an Alltech Adsorbosphere HS C_(18) column,using 5×10^(-3)M NaH_2PO_4-H_3PO_4 buffer solution(pH 3.0)and acetonitrile-water(50:50)as gradient eluents. The baseline separation of ginsenosides Rb_1,Rb_2,Rb_1,Rc,Rd,Rf,Ro,and Re+Rg_1 was obtained in one analytical run.The ginsenosides are directly detected at 203 nm.The detection limit is 40μg at a signal to noise ratio of 3:1.The improved sample preparation and clean-up prior to injection with SEP-PAK C_(18)cartridge strongly reduced the front peaks caused by the impurities in the methanolic extracts of samples to afford a smooth baseline and clear background.The HPLC patterns of methanolic extracts mainly including the ginsenosides were found capable of serving as chemical fingerprints to differentiate the three species from each other.It was also found that there are no significant diffe- rences of the HPLC patterns between the wild Panax ginseng and the cultivated,the white and the red ginsengs,Chinese and Korean red ginsengs,and the tap roots of Panax ginseng collected in four consecutive months,only certain differences in contents of ginsenosides do exist.The contents of the nine major ginsenosides present in the rhizome,tap root and rootlet as well as the leaf of Panax quinquefolium were also determined and compared.

Quantification of six bioactive compounds in Zhenqi Fuzheng preparation by high-performance liquid chromatography coupled with diode array detector and evaporative light scattering detector

A simple and accurate high-performance liquid chromatography（HPLC）coupled with diode array detector（DAD）and evaporative light scattering detector（ELSD）was established for the determination of six bioactive compounds in Zhenqi Fuzheng preparation（ZFP）.The monitoring wavelengths were 254,275 and 328 nm.Under the optimum conditions,good separation was achieved,and the assay was fully validated in respect of precision,repeatability and accuracy.The proposed method was successfully applied to quantify the six ingredients in 31 batches of ZFP samples and evaluate the variation by hierarchical cluster analysis（HCA）,which demonstrated significant variations on the content of these compounds in the samples from different manufacturers with different preparation procedures.The developed HPLC method can be used as a valid analytical method to evaluate the intrinsic quality of this preparation.

Biological Fingerprinting Analysis of Interaction Between Taxoids in Taxus and Microtubule Protein by Microdialysis Coupled with High-performance Liquid Chromatography/Mass Spectrometry for Screening Antimicrotubule Agents

Some natural products, such as traditional Chinese medicines（TCMs）, contain compounds with anticancer activity and have attracted a great interest in recent years as alternative anticancer therapies. A quick and convenient assay for screening antimicrotubule compounds in which in vitro microdialysis/high-performance liquid chromatography （HPLC） is used to monitor the binding of the compounds extracted from TCM Taxus cuspidata Siebold ＆ Zucc（Taxus） to microtubules is reported. It was observed that the extract of Taxus contains at least five compounds which have affinity interaction with microtubules by biological fingerprinting analysis, and they were identified as the taxoids of taxol, baccatin III, 10-deacetylbaccatin Ⅲ（10-DAB）, cephalomannine and 7-epi-10-deacetyltaxol （7-epi-10-DAT） based on the comparison of their high-performance liquid chromatographic/mass spectrometric and UV spectra with those of the standard samples, both assembly-promoting and disassembly-inhibiting characteristics of those compounds were evaluated. It was observed that baccatin Ⅲ and 10-DAB bound to microtubules and the binding degrees were influenced by GTP. Competitive binding behavior of taxol with other four taxoids to microtubules was also investigated.

HPLC Fingerprint with Multi-components Analysis for Quality Consistency Evaluation of Traditional Chinese Medicine Si-Mo-Tang Oral Liquid Preparation

Si-Mo-Tang（SMT） oral liquid preparation, a traditional Chinese medicine, was prepared from four crude herbal drugs, Fructus Aurantii Submaturus, Radix Aucklandiae, Semen Arecae and Radix Linderae Aggregatae. A combinative method using HPLC fingerprint and quantitative analysis was developed and validated for quality consistency evaluation of SMT. Individual HPLC chromatograms were evaluated against the mean chromatogram generated via a similarity evaluation computer program. Data from chromatographic fingerprints were also processed with principal component analysis（PCA） and hierarchical cluster analysis（HCA）. Additionally, six components （naringin, isonaringin, hesperidin, neohesperidin, norisoboldine and potassium sorbate） in SMT were simultaneously determined to interpret the quality consistency. For fingerprint analysis, 20 peaks were selected as the characteristic peaks to evaluate the similarities of 26 SMT collected from different manufacturers. Among the 20 characteristic peaks, 10 peaks were assigned to be naringin, hesperidin, neohesperidin, isonaringin, neoeriocitrin, tangeretin, nobiletin, norisoboldine, 5-（ethoxymethyl）furan-2-carbaldehyde and potassium sorbate, respectively. The results of similarity analysis, PCA and HCA, indicate that the samples from different manufacturers were consistent with each other in composition. The results from the quantitative data show that the contents of six compounds were significantly different in SMT oral liquid preparations from different manufacturers. The combinative method of chromatographic fingerprint with quantitative analysis developed here offered an efficient way for the quality consistency evaluation of the traditional Chinese medicine SMT.

Determination of anthraquinone prodrug and its hydrolytically active compounds using RP-HPLC

In order to study the hydrolytic characterization of an anti-inflammatory prodrug （ RI-1 ） in vitro, an effective, accurate and reliable method for the simultaneous determination of the prodrug and its two hydrolytic active compounds is developed using reverse phase high-performance liquid chromatography （RP-HPLC）. The chromatographic separation is performed on an ODS-2 C18 column （250 mm × 4. 6 mm, 5.0 μm particle size） with a simple elution program. The mobile phase is V（ methanol） ： V（0. 1% phosphoric acid solution） =90：10 （adjust pH to 2. 3）. A wavelength of 225 nm and a mobile phase flow rate of 1.0 mL/min are utilized for the quantitative analysis. Excellent linear behaviors over the investigated concentration ranges are observed with values of R2 higher than 0. 999 for all the analytes. The validated method is successfully applied to the simultaneous determination of the prodrug and its active components can be used to detect hydrolytic characterization in vitro.

Extraction and RP-HPLC determination of taxol in rat plasma, cell culture and quality control samples

A rapid, sensitive, selective and validated reverse phase high-performance liquid chromatography （RP-HPLC） method for the estimation of paclitaxel in micro-sample of rat plasma and in culture of cancer cells was per- formed in this study. The mobile phase consisted of an （80： 20： 0.1, v/v/v）. Column elution at a flow rate of 1 optimized mixture of methanol：water： trifluroacetic acid mL/minute with UV detection at 225 nm at room tern- perature was used. The RP-HPLC method was successfully applied for the determination of paclitaxel in plasma samples and in culture of cancer cells with nano-quantity of estimation. The validation studies were performed in accordance with the International Conference on Harmonization （ICH） guidelines. The intra- and inter-day pre- cision showed that the coefficients of variation ranged from 1.07% to 4.27% at different levels of concentrations. To the best of our knowledge, this study also reported for the first time the optimization of different solvents for effective extraction of paclitaxel wherein tert.-butyl methyl ether （TBME）： diethyl ether （DEE） in 50：50 v/ v composition was found most efficient with extraction efficiency ranging between 77.99% and 91.74% and be- tween 76.14 and 93.66% in the plasma and cell culture, respectively. This proposed method was successfully ap- plied to study the pharmacokinetics of paclitaxel and the influence of verapamil and all-trans retinoic acid （atRA） on paclitaxel pharmacokinetics in rat models. This proposed method might emerge as a valuable aid in the labo- ratory monitoring of paclitaxel in a variety of in vitro as well as in vivo scenarios.

HPLC Fingerprint Chromatogram of Tetracera asiatica Produced in Guangxi

[Objectives] To establish fingerprint chromatogram of Tetracera asiatica and provide basis for controlling and assessing the quality of Tetracera asiatica.[Methods] The high-performance liquid chromatography( HPLC) method was used. Phenomenex C18( 5 μm,4. 6 ×250 mm),acetonitrile-0. 1% phosphoric acid water,gradient elution,flow rate 1 m L/min,detection wavelength 214 nm,and column temperature 25 ℃. The fingerprint chromatogram of 10 batches of samples of Tetracera asiatica was determined for similarity comparison. [Results] It established HPLC fingerprint chromatogram of Tetracera asiatica produced in Guangxi,determined a total of 13 common fingerprint peaks. The similarity of 10 batches of Tetracera asiatica was > 0. 9.[Conclusions] The method is rapid and accurate and can provide references for assessing the quality of Tetracera asiatica.

Freshwater algae chemotaxonomy by high-performance liquid chromatographic(HPLC)analysis

The study of community composition of algae is essential for understanding the structure and dynamics of the aquatic ecosystem and for evaluating the eutrophic level of the water body.A high-performance liquid chromatographic(HPLC)method based on a reversephase C_(18) nonpolar column was developed for the main algal taxa,which includes cyanophytes,bacillariophytes,euglenophytes,dinophytes,and chlorophytes.Based on the elution order using HPLC,19 pigments were identified,and they were chlorophyllide a,19′-butanoyloxyfucoxanthin,chlorophyll c_(1)+c_(2),phephorbides a,peridinin,methyl-chlorophyllide a,fucoxanthin,neoxanthin,violaxanthin,myxoxanthophyll,diadinoxanthin,diatoxanthin,lutein,zeaxanthin,chlorophyll b allomer,chlorophyll b,chlorophyll a allomer,chlorophyll a,andβ,β-carotene.A comparison study of cell microscopic counts and accessory pigment analysis indicated that HPLC analysis could be a useful tool for monitoring phytoplankton communities and their abundance.

Characterization of impurities in the bulk drug lisinopril by liquid chromatography/ion trap spectrometry

Two trace impurities in the bulk drug lisinopril were detected by means of high-performance liquid chromatography coupled with mass spectrometry （HPLC/MS） with a simple and sensitive method suitable for HPLC/MSn analysis. The fragmentation behavior of lisinopfil and the impurities was investigated, and two unknown impurities were elucidated as 2-（6-amino- l-（l-carboxyethylamino）- l-oxohexan-2-ylamino）-4-phenylbutanoic acid and 6-amino-2-（l-carboxy-3-phenylpropylamino）-hexanoic acid on the basis of the multi-stage mass spectrometry and exact mass evidence, The proposed structures of the two unknown impurities were further confirmed by nuclear magnetic resonance （NMR） experiments after preparative isolation.

Simultaneous Determination of Three Components in Herba Taxilli from Different Host Trees by HPLC

[Objectives] To establish a HPLC method for the simultaneous determination of three components( namely,quercetin,quercitrin and avicularin) in Herba Taxilli. [Methods]Agilent C18 liquid chromatography column( column size: 150 mm × 4. 6 mm,5 m) was used;mobile phase Dacetonitrile∶ water = 22∶ 78; flow rate: 1. 0 m L/min; column temperature: 35℃; injection volume: 10 μL; detection wavelength: 254 nm. [Results]The injection volume of quercetin,quercitrin and avicularin was in a good linear relationship with the peak area in the range of 0. 22-4. 4 μg( R = 1),0. 096-3. 84 μg( R = 0. 999 6),and 0. 106-5. 3 μg( R = 0. 999 9),and the average sample recovery was 99. 32%,100. 53%,and 98. 96%,respectively. [Conclusions]The stability and reproducibility of the established method for determining the content of Herba Taxilli in this experiment are good,and it is expected to provide reference for its quality control and evaluation.

Rapid HPLC Method for Monitoring Relevant Residues of Pharmaceuticals Products in Environmental Samples

This work presents a multi-residue analytical method based on solid phase extraction (SPE) followed by high-performance liquid chromatographic (HPLC) with diode array (DAD) detection for the simultaneous determination of a group of pharmaceutical products that include ten antidepressants and three anticanceri- genic in environmental samples (water and soil). Baseline separation of the studied compounds was obtained on an ultrabase C18 (4.6 mm i.d. × 150 mm, 5 μm particle) column using acetonitrile:phosphate buffer pH 2.5 (35:65 v/v) as mobile phase with a flow rate of 1.5 mL/min. Different aspects including linearity, accuracy, precision and detection and quantification limits were examined in order to validate the proposed method. Detection limits between 1 and 50 ng/mL were obtained for all the target compounds. This method was ap- plied to the analysis of environmental samples as waters and soils of different precedence. Prior, the HPLC determination the samples were purified and enriched using SPE or liquid-liquid extraction (LLE) of the tar- get compounds.

Determination of Amantadine Residue in Honey by Solid-phase Extraction and High-performance Liquid Chromatography with Pre-column Derivatization and Fluorometric Detection

Amantadine （AMA） is an anti-viral drug used in apiculture to protect honeybee against the sacbrood virus （Morator aetatulae）. This study described a reliable high-performance liquid chromatographic （HPLC） method for analyzing AMA in honey using a solid-phase extraction （SPE） cartridge （Plexa PCX） for purification, 4-fluoro-7- nitro-2,1,3-benzoxadiazole （NBD-F） as a pre-column derivatization agent, and fluorometric detection （λex =470 nm, λem=530 nm）. The chromatographic separation was performed on an XDB C18 column （150×4.6 mm i.d.） using 0.1% trifluoroacetic acid/acetonitrile （35 ; 65, V/V） as the mobile phase at a flow rate of 1.0 mLomin 1 with a run time of 20 min. Under these optimal conditions, a linear relationship was observed in the range of 0.025--1.0μg·mL-1 with a good correlation coefficient （0.998） and low limit of detection （0.0080 μg·g-1）, the recoveries were all above 90%, and the intra-day and inter-day precision （RSD） ranged from 3.4%--5.1%.

Determination of Four Pesticides in Soil by Homogeneous Ionic Liquid-based Microextraction Coupled with High-performance Liquid Chromatography

Homogeneous ionic liquid microextraction was developed for the simultaneceus extraction of dimetho- morph, mefenacet, isoprothiolane and oxadiazon from soil. 1-Butyl-3-methylimidazolium tetrafluoroborate was used as extraction solvent, and ammonium hexafluorophosphate was used as ion-pairing agent. High-performance liquid chromatography（HPLC） was employed for separation and determination of the analytes. The calibration curves show good linear relationship（r〉0.9988）. The recoveries are between 74.2% and 97.9% with relative standard devia- tions（RSDs） lower than 5.97%. The present method is free of volatile organic solvents, and expenditures of sample, extraction time and solvent are lower, compared with ultrasonic and Soxhlet extraction. There was no obvious diffe- rence in the extraction recoveries of pesticides obtained by the three extraction methods.

冰片对大鼠血浆儿茶酚胺类物质影响的实验研究

[目的]观察冰片对大鼠血浆儿茶酚胺 (CA)类物质去甲肾上腺素 (NE)、肾上腺素 (E)含量的影响 ,同时进行量效关系的观察 ,初步探讨冰片的作用靶点和作用机制。[方法]将40只wistar大鼠随机分组后 ,分别灌服生理盐水 ,1%羟甲基纤维素钠 (CMC -Na) ,以及高、中、低剂量的冰片 ,2次/d,灌胃24h后 ,用高效液相 -电化学法检测大鼠血浆儿茶酚胺类物质NE、E含量。[结果]1)灌服冰片24h后 ,冰片各剂量组血浆NE含量均有下降 ,其中冰片中组、高组和CMC -Na组相比有统计学差异 (P<0.05) ;2)灌服冰片24h后 ,冰片各组与CMC -Na组相比呈现降低作用 ,其中冰片中剂量组有统计学性差异 (P<0.05)。[结论]冰片对于交感神经的兴奋性和儿茶酚胺类物质释放有一定抑制作用 ,据此推测冰片可能通过影响神经内分泌功能 ,进而调节机体的生理病理活动 。

Processing of Aniline Aerofloat Wastewater with SBR System and Its Biodegradation Mechanism

ObjectiveThis study aimed to investigate the biodegradation effect and biodegradation mechanism of aniline aerofloat wastewater. MethodSmall-scale processing of simulated aniline aerofloat wastewater was carried out with SBR （Sequencing Batch Reactor） system; intermediate products in the process were analyzed using high-performance liquid chromatography. ResultAccording to the experimental results, the small-scale process was basically stably operated after 40 days of activation and regulation, leading to relatively ideal degradation effect on aniline aerofloat, the COD removal efficiency reached 64.3% , degradation rate of aniline aerofloat reached 93.4%, which could be applied in the treatment of mine flotation wastewater containing such pollutant. During the degradation process, pH increased from 5.83 to 6.60 and then dropped to 6.17, which might be caused by the thiocyanate ions and aniline generated in the degradation process. Aniline aerofloat mainly produced two preliminary products during the biodegradation process： aniline and a substance that was difficult to be biodegraded under aerobic conditions, which was the main reason for the relatively high COD value in effluent. Furthermore, aniline was eventually biodegraded. ConclusionThis study provided basis for the development of biological treatment of flotation wastewater in China and showed great significance for the improvement of ecological environment around the mines.

酶法生产大豆蛋白ACE抑制肽的研究

研究了Alcalase碱性蛋白酶、Neutrase中性蛋白酶、Protames复合蛋白酶、Flavourzyme风味蛋白酶对大豆分离蛋白的水解效果和ACE(血管紧张素转化酶)的抑制活性。水解能力用pH-start法检测,水解度大小依次为:Alcalase碱性蛋白酶>Protames复合蛋白酶>Neutrase中性蛋白酶>Flavourzyme风味蛋白酶;ACE抑制活性用高效液相法检测,ACE抑制率强弱依次为:Alcalase碱性蛋白酶>Flavourzyme风味蛋白酶>Protames复合蛋白酶>Neutrase中性蛋白酶。综合考虑,选定Alcalase碱性蛋白酶为生产大豆ACE抑制肽的最适酶,并对其酶解条件进行了优化,确定生产大豆ACE抑制肽的最佳条件为:温度60℃、pH8.0、[S]=4%、[E]/[S]=4%,这时的水解度为14.4%。

高效液相色谱法测定白菜中农药马拉硫磷残留量

采用高效液相色谱法测定了白菜中农药马拉硫磷残留量.研究结果显示:在10.0-50.0μg/mL浓度范围内峰面积与进样量具有良好的线性关系,相关系数r=0.999 6;相对标准偏差RSD为0.21%(以峰面积计算)和0.84%(以浓度计算);平均加标回收率在85.6%-106.0%之间;最低检出限LOD=2.0μg/L.

大豆降压肽的生产工艺研究

应用4种蛋白酶酶解大豆分离蛋白,研究其水解效果和降压活性。实验选定碱性蛋白酶为生产大豆降压肽的最适酶,并对其酶解条件进行了优化,确定生产大豆降压肽的最佳条件为:温度60℃,pH8.0,底物浓度4%,碱性蛋白酶浓度4%,水解度14.4%,优化后的ACE抑制率可达到84.1%。