Plasma free amino acid profiling of esophageal cancer using high-performance liquid chromatography spectroscopy

AIM: To perform plasma free amino acid (PFAA) profiling of esophageal squamous cell carcinoma (ESCC) patients at different pathological stages and healthy subjects.

Determination of Trace Amount of Polycyclic Aromatic Hydrocarbons in Urban Sewage by Solid-phase Extraction Coupled with High Performance Liquid Chromatograph

[Method] This study aimed to determine trace amount of polycyclic aromatic hydrocarbons(PAHs) in urban sewage by using solid-phase extraction(SPE) coupled with high performance liquid chromatograph(HPLC).[Method] From the aspects of solid-phase extraction column,elution solvent,elution volume,elution speed and so forth,the test conditions of SPE-HPLC method were optimized,and trace amount of PAHs in urban sewage was determined.[Result] The optimized solid-phase extraction conditions were SUPELCLEAN LC-18 solid-phase extraction column,methylene dichloride as elution solvent,15 ml elution volume,2 ml/min elution speed,5 ml/min loading speed,1 000 ml water with 200 ml methanol loading volume.Under the optimized extraction conditions,the recovery was high,namely 76.3%-105.2%;relative standard deviation was 3.8%-6.0%,showing good precision;detection limit was low,only 0.000 8-0.048 0 μg/L.[Conclusion] This method is user-friendly,with high sensitivity and good precision,and suitable for continuous determination of a large volume of water samples.

Creation of reversed phase high-performance liquid chromatographic technique to assay platelet-activating factor

Objective: To establish a new assay for platelet-activating factor (PAF), to compare it with bio-assay; and to discuss its significance in some elderly people diseases such as cerebral infarction and coronary heart disease. Methods: To measure PAF levels in 100 controls, 23 elderly patients with cerebral infarction and 65 cases with coronary heart disease by reversed phase high-performance liquid chromatographic technique (rHPLC). Results:rHPLC is more convenient, sensitive,specific, and less confusing, compared with bio-assay. The level of plasma PAF in patients with cerebral infarction was higher than that in the controls (P<0.01), and in patients with coronary heart disease. Conclusion: Detection of PAF with rHPLC is more reliable and more accurate. The new assay has important significance in PAF research.

Preparative Optimization of Cellulose Microspheres Applied as Supports for High-Performance Liquid Chromatography

The aim of this work is optimizing the techniques to prepare pure cellulose microspheres, which are used as packing adsorbents for high-performance liquid chromatography. Thereupon, cellulose was dissolved in a pre-cooled NaOH/urea solution, from which various-size microspheres were prepared. The volume-average diameters were controlled approximately at 30 p,m, 8 ~tm and 4 pm grades when cyclohexane, liquid paraffin and pump oil were used as dispersants, respectively. The present investigations reveal that higher viscosity dispersant is suitable for the preparation of smaller-size microspheres, while larger size microspheres are prepared preferably using lower-viscosity dispersant. The chiral stationary phase derived from 8 μm grade microspheres can separate the enantiomers of efavirenz.

HIGH-PERFORMANCE LIQUID CHROMATOGRAPHIC SEPARATION OF FULLERENES

High-performance liquid chromatographic systems for the separation of buckminsterfullerene(C_(60)) and related fullerene C_(70) were investigated with methanol/benzene or methanol/toluene (35/65-60/40 in Ⅴ/Ⅴ) as eluant in C18 reversed phase column. The system is suitable for fast analysis of fullerenes at lower percentage of methanol, and repeatly large scale perparation at higher percentage of methanol.

HIGH-PERFORMANCE LIQUID CHROMATOGRAPHIC ANALYSIS OF KR-008 IN BIOLOGICAL FLUIDS

A high-performance liquid chromatographic method for the simultaneous determination of KR-008 and its metabolite in biological fluids was developed The samples were injected directly without further treatment,the compounds were separated and analysed on a reversed- phase column under isocratic conditions,including ion pairing.Concentrations in urine and bile were determined by an external standard method.The detection limit was 0.8μg/ml in urine.Preliminary data showed that,following i.p.administration(120mg/kg)of KR-008 to rats,approximately 2.8% of the dose was excreted in urine as unchanged compound and more than 8.9% was as a metabolite;in bile it was 0.73% excreted as unchanged form and above 0.29% as the metabolite.The peak biliary concentration of KR-008 was 0.39mg/ml at 20min after dosing.

High Performance Liquid Chromatographic Determination of Phenolic Acids in Fruits and Vegetables

A simple isocratic HPLC technique has been developed for the quantitative analysis of phenolic acids (PAs) in fruits and vegetables. Nine benzoic and cinnamic acid derivatives were separated in less than 30 min, and the resolution was all more than 1.23. The ranges of linearity for PAs standards were 0.2-100 ng, even up to 600 ng (r = 0.983-1.000) and the detection limits were 0.02-0.24 mg/kg. Samples of fresh vegetables and fruits were extracted with 80% mcthanol and ethyl acetate, then purified with C18 Sep-Pak cartridge and determined by HPLC. This method was applied to the determination of PAs in 7 kinds of fruits and vegetables, i.e., apple, pear, Chinese cabbage, cauliflower, turnip, soybean sprout and white grape wine. The content of the 9 PAs varied widely in the 7 kinds ol'foods studied. The average concentrations ofchlorogenic acid in apple (100.2 mg/kg) and pear (30.8 mg/kg) were quite high, and sinapinic acid was remarkable (42.5 mg/kg) in Chinese cabbage, and protocatechuic acid had the highest concentration of all the PAs in white wine.

High-performance liquid chromatographic fingerprint analysis of Oxytropis falcata Bunge and Oxytropis chiliophylla Royle

A simple, sensible and reliable HPLC-DAD fingerprint analysis method for the raw materials of Oxytropisfalcata and Oxytropis chiliophylla, both of which were used as ＂Er-Da-Xia＂ in Tibetan medicines, was developed and then subsequently applied to analyze samples collected from different locations or times. 19 common fingerprint peaks for O. falcata, 24 for O. chiliophylla, and 11 for the two herbs were designated respectively, including 7 identified characteristic peaks existing in both herbs and 1 uniquely presenting in O. chiliophylla. Although there were some slight differences in the chemicals of O. falcata and O. chiliophylla, the main components of both herbs were consistent generally. The results provided scientific basis, at least from the chemical point of view, for the reasonablity of two herbs being used as the same drug in Tibetan medicines and for the necessary of further investigation on their detailed chemical and pharmacological differences.

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 Polysaccharide in Radix pseudostellariae Extract by Size-Exclusion High-Performance Liquid Chromatography

A simple size-exclusion high-performance liquid chromatographic method was developed for rapid molecular mass screening to determine the average molecular mass, polydispersity, and quantity of Taizishen polysaccharides extract. The screening used a TOSOH TSK-GEL G3000SW high-performance liquid chromatographic column with 0.1 mol/L NaNO3 buffer as the mobile phase and refractive index detector. The molecular mass calibration curve was linear for polysaccharide standards from 10 to 100 kDa with a correlation coefficient of 0.9991. The method can be used to analyze the quantity, average molecular mass, and polydispersity of polysaccharides. In addition, the screening method is suitable for quality control of polysaccharide preparations in Chinese medicines and pharmaceutical products.

Ultra-High-Performance Liquid Chromatograph with Triple-Quadrupole Mass Spectrometer Quantitation of Twelve Phenolic Components in Different Parts of Sarcandra glabra

Objective:The study objective was to determine phenolic components for the quality control(QC)of cultivated Sarcandra glabra(Thunb.)Makino(S.glabra).Materials and Methods:A sensitive,ultra-high-performance liquid chromatography-tandem mass spectrometric method for the simultaneous determination of 12 phenolic components has been developed.Six caffeoylquinic acids,two caffeoylshikimic acids,and four flavanonol glucosides were selected for the comprehensive analysis of distribution in different parts(root,stem,and leaf).Results:Twelve phenolic components were linear in the concentration range of 0.005–5.0μg/mL(R^(2)>0.995).The relative standard deviation of intra-day and inter-day precision across three validation runs over the entire concentration range was<5%.The recovery determined was within 5%in terms of relative error.Our results showed that the 12 phenolic compounds were mainly distributed in leaves and stems far more than those in roots.Conclusions:This study provided an ultra-high-performance liquid chromatograph with triple-quadrupole mass spectrometer quantitative method of 12 phenolic components for the QC of cultivated S.glabra.It was found that the phenolic components were significantly accumulated in the aerial parts(stems and leaves)of cultivated S.glabra.

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.

Control System for Low Pressure Gradient Mixer in High Performance Liquid Chromatograph

A control system used in high performance liquid chromatograph(HPLC) was described.The control system adopting low pressure gradient elution was tested with different initial and end volume fractions,and four types of gradient elution curves.The experimental results verified the theoretical analyses of the applied method.This self-designed control system can achieve approving accuracy,repeatability and low cost,which has a bright outlook for domestic applications.

Predicting a, c indices in reversed-phase high-performance liquid chromatography (RP-HPLC) from Kovats index in gas chromatography (GC)

KOVATS index is the most precise index system reflecting the interaction between the molecules of solutes and stationary phase in gas chromatography at present. Large quantity of Kovats in dex data have been published. It is a good way to use Kováts index in gas chromatography to predict the retention value in liquid chromatography, which is significant in theory and apphcation.

A Study on Relationship Between Gas Chromatographic Retention Value and Atomic Hydrophobic Parameters

A study on relationship between molecular structure and chromatographic retention values for realizing the identification and prediction of chromatographic retention values has been the major task of chromatographic thermodynamics. In 1964, Prof. Lu Peizhang established the relationship between molecular structural parameters and chromatographic retention values in gas-liquid chromatography by using statistical thermodynamical methods. Based on his work, some Chinese researchers have performed the prediction of chromatographic retention values.

QuEChERS EMR-Lipid净化结合同位素稀释-超高效液相色谱-串联质谱法同时测定蜂房及其制剂中10种真菌毒素

目的 建立一种Qu ECh ERS EMR-Lipid净化结合同位素稀释-超高效液相色谱-串联质谱技术(UPLC-MS/MS)同时测定蜂房及其制剂中10种真菌毒素的检测方法。方法 样品经80%乙腈水溶液提取,Qu ECh ERS EMRLipid净化,采用UPLC-MS/MS,在多反应监测(MRM)模式下进行测定,内标法定量。结果 10种真菌毒素含量在各自质量浓度范围内具有较好的线性关系(r>0.999),目标化合物在低、中、高3个质量浓度下的平均回收率为83.8%~107.1%(RSD<6.5%),定量限(LOQ)为0.18~129μg/kg。结论 该法前处理步骤简便,净化效果良好,提高了样品检测效率,内标法定量精准可靠,适用于蜂房及其制剂中10种真菌毒素的同时检测。

固相萃取-超高效液相色谱-三重四极杆/线性离子阱质谱法检测水中大环内酯类抗生素

采用固相萃取-超高效液相色谱-三重四极杆线性离子阱质谱技术(SPE-UPLC-QTRAP MS)建立了环境水样中阿奇霉素、林可霉素、克林霉素、红霉素及替米考星5种大环内酯类抗生素的检测方法。调节水样pH为10后经HLB固相萃取柱净化、富集,然后用Kinetex F5色谱柱进行分离,用0.1%甲酸水溶液和0.1%甲酸乙腈溶液进行洗脱,采用电喷雾正离子源(ESI+),多反应监测(MRM)-信息依赖采集(IDA)-增强子离子(EPI)扫描模式对样品进行检测,用多反应监测(MRM)进行定量,增强子离子(EPI)谱图库辅助定性。结果表明:5种大环内酯类抗生素线性关系良好,相关系数均大于0.9992;检出限为0.01~0.30μg·L^(-1),定量限为0.10~0.50μg·L^(-1);3种不同浓度的水样加标回收率为71.60%~111.05%,相对标准偏差均在10%以内,EPI谱库比对纯度值均大于90%。该方法将传统的MRM扫描模式结合EPI谱图库检索,实现了同时定性和定量分析,对未知物准确定性定量检测提供了重要参考。

不同干燥方式八角果实挥发性化合物代谢组分析

【目的】探明不同干燥方式对八角果实挥发性成分的影响,筛选出适宜八角果实干燥的处理方式,为八角后期深加工、保存及应用提供参考。【方法】以新鲜八角果实为材料,采用自然晾晒、40℃、50℃、60℃、70℃、80℃和90℃烘干7种处理方式进行干燥,通过液相色谱-质谱(LC-MS)技术检测分析八角果实代谢产物,阐明八角果实不同温度干燥与自然晾晒处理的代谢物差异。【结果】与自然晾晒相比,八角果实40℃干燥差异代谢产物有11类17种,其中,萜类、醇类和醛类3类代谢物上调;50℃干燥差异代谢物有10类25种,其中,上调代谢物6类(萜类、醇类、酯类、酮类、卤代烃类、酚类);60℃干燥差异代谢物有8类13种,其中,醇类和烃类代谢物上调;70℃干燥差异代谢物为13类40种,其中,醇类、萜类和酯类3类代谢物上调;80℃干燥差异代谢物有13类38种,仅醇类代谢物上调;90℃干燥差异代谢物有13类52种,其中,上调代谢物4类(萜类、醇类、酮类、卤代烃类)。40℃、50℃和60℃干燥的八角果实与自然晾晒差异代谢物较少,上调代谢物主要是苯甲醛、醋酸植物醇、茴香脑、6-异羟基樟脑、乙酸异丁香酚酯和甲基丁香酚等挥发性化合物,提升了八角浓厚的香味。70℃、80℃和90℃干燥的八角果实与自然晾晒差异代谢物较多,且与八角香味相关的许多代谢物下调表达,主要有香芹酮、茴香脑、E-氧化玫瑰、4-蒈烯、对薄荷脑1,5,8-三烯、苯甲醛、芳樟醇、3-甲基苯并噻吩、2-甲基-2-四氢呋喃和2-乙酰基-5-甲基呋喃等挥发性化合物,减弱了八角香味。【结论】不同干燥处理八角果实的挥发性化合物种类均存在一定差异。40℃、50℃和60℃干燥八角果实,苯甲醛、醋酸植物醇和茴香脑等上调表达的挥发性化合物提升了八角香味。八角果实经50℃干燥后,上调表达的代谢物有萜类、醇类、酯类、酮类、卤代烃类和酚类6类,果实独特香气保持最好,宜在生产上推广应用。

液液萃取-气相色谱质谱法测定水质中的环氧氯丙烷

比较了不同前处理方法进行水质中环氧氯丙烷的测试,其中液液萃取的前处理方法简单可靠,方便易行,适合复杂基质水样的测定。同时比较了气相色谱仪不同检测器对环氧氯丙烷(ECH)的响应值,其中质谱检测器对ECH的响应值最高。液液萃取-气相色谱质谱法测定水质中的环氧氯丙烷,该方法的检出限为0.6μg/L,测定下限为2.4μg/L。对海水、地表水、工业污水样品加标浓度为0.001 mg/L、0.02 mg/L、0.2 mg/L进行平行6次测定,结果的相对标准偏差分别为6.9%、2.7%和6.3%,加标回收率分别为93.5%、99.0%和99.6%,非常适合各类水质ECH的监测。