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.

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 Organic Acids in Root Exudates by High Performance Liquid Chromatography:Ⅱ.Influence of Several Testing Conditions

Effects of column temperature and flow rate on separation of organic acids were studied by determining nine low-molecular-weight organic acids on reversed- phase C18 column, using high performance liquid chromatography (HPLC) with a wavelength of UV (ultraviolet) 214 urn and a mobile phase of 18 mmol L-1 KH2PO4 buffer solution (pH 2.1). The thermal stability of organic acids was determined by comparing the recoveries of organic acids in different temperature treatments. The relationships between column temperature, flow rate or solvent pH and retention time were analyzed. At low solvent pH, separation efficiency of organic acids was increased by raising the flow rate of the solvent because of lowering the retention time of organic acids. High column temperature was unfavorable for the separation of organic acids. The separating effect can be enhanced through reducing column temperature in organic acid determination due to increasing retention time. High thermal stability of organic acids with low concentrations was observed at temperature of 40 ℃-45℃. Sensitivity and separation effect of organic acid determination by HPLC were clearly improved by a combination of raising flow rate and lowering column temperature at low solvent pH.

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.

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.

Study on chromatographic fingerprint of sarcandra glabra (Thunb.) by microwave-assisted extraction coupled to HPLC/DAD

Microwave-assisted extraction(MAE)was used for extraction of effective components of sarcandra glabra(Thunb.),and then chromatographic fingerprint of sarcandra glabra(Thunb.)was studied by high performance liquid chromatography/diode array detector(HPLC/DAD).The conditions of MAE were optimized by an orthogonal experiment,and then the authentication and validation of the chromatographic fingerprint were conducted.Nine peaks were identified as common peaks in the fingerprint chromatograms,and isofraxidin was considered as a reference compound and quantified.Relative standard deviations of retention time and peak area of each component were less than 3% and 8%,respectively.Similarity and difference analysis were conducted by use of PCA and relation coefficient.Twenty batches of sarcandra glabra(Thunb.)samples from two different producing areas could be classified into two different groups in the PCA model.The results showed that MAE-HPLC/DAD method was simple,efficient and stable for the study of complex chromatographic fingerprint of sarcandra glabra(Thunb.),which could provide more reliable and precise information for quality evaluation.

Determination of Doxycycline in Doxycycline Hydrochloride Soluble Powder under Different Chromatographic Conditions

[Objectives]This study was conducted to compare the accuracy and detection speed of high performance liquid chromatography for determining the content of doxycycline hydrochloride in doxycycline hydrochloride soluble powder under different chromatographic conditions, in order to improve the level of laboratory testing. [Methods] Four sets of experiments were designed through a cross-test method. The contents of doxycycline hydrochloride in the raw materials of doxycycline hydrochloride and doxycycline hydrochloride soluble powder were determined by changing the chromatographic column and mobile phase conditions, and the feasibility and practicability of the four methods were judged by comparing the detection results through data and chromatographic signal processing. [Results] The content of doxycycline hydrochloride in finished doxycycline hydrochloride soluble powder and the raw materials of doxycycline hydrochloride could be accurately determined under the four chromatographic conditions, of which the experimental group using Agilent C18 column and the mobile chromatography conditions of finished doxycycline hydrochloride soluble powder had the shortest retention time. [Conclusions] The high performance liquid chromatography method using Agilent C18 chromatographic column and mobile phase chromatographic conditions of finished doxycycline hydrochloride soluble powder products can quickly and accurately determine the content of doxycycline hydrochloride in doxycycline hydrochloride soluble powder.

不同超高效液相系统对色谱柱柱效能测定结果的影响

目的探索GB/T 30433⁃2021中柱效能的测试参数,是否适用于高效液相色谱柱。方法比较同一超高效液相系统下,不同甲醇/水溶液流动相比例(40∶60,50∶50,55∶45),不同流量(0.20 mL/min,0.22 mL/min,0.25 mL/min,0.28 mL/min,0.30 mL/min),不同进样量(0.1μL,0.2μL)对高效液相色谱柱柱效能的影响;比较两种超高效液相系统(1290 Infinity II和APUS Plus),在两种不同色谱参数(色谱参数一∶乙腈/水溶液=40∶60,流量=0.5 mL/min,进样量=1.0μL;色谱参数二∶甲醇/水溶液=50∶50,流量=0.20 mL/min,进样量=0.2μL)下,对高效液相色谱柱柱效能每米理论板数的影响。结果同一超高效液相系统,在甲醇/水溶液比例为50∶50,流量为0.20 mL/min,进样量为0.2μL的色谱参数下,高效液相色谱柱柱效能每米理论板数的结果较优;不同超高效液相色谱系统下每米理论板数测试结果差异较大。结论不同超高效液相系统下,柱效能每米理论板数的测定结果除受色谱柱自身性能和色谱参数的影响,还与系统及检测器等柱外硬件相关。

超高效液相色谱在洗洁精表面活性剂检测中的应用

为了能够更加精准地检测洗洁精表面活性剂含量,提出超高效液相色谱在洗洁精表面活性剂检测中的应用研究。考虑到大部分洗洁精应用的表面活性物质均为甜菜碱或氧化胺类物质,设置了以甜菜碱和氧化胺类物质为核心的超高效液相色谱试剂,选择U3000高效液相色谱仪,日本新宇宙XP-302M电雾式检测器以及Acclaim Surfactant Plus分析柱作为具体的测试装置,对测试环境温度和U3000高效液相色谱仪的流速进行定值设置后,按照乙腈洗脱执行梯度对色谱柱进行处理后,将满足线性范畴的数据作为计算洗洁精表面活性剂含量的基础参数,带入到回归方程中,确定各表面活性剂含量,对应的检测结果误差稳定在0.015%以内,单一类别洗洁精表面活性剂含量检测结果误差稳定在0.003%以内。

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.

Preparation and Characterization of a New Quercetin-bonded Stationary Phase for High Performance Liquid Chromatography

A quercetin-bonded silica gel stationary phase （QUSP） containing natural flavonoid ligand was first prepared via γ-glycidoxypropyltrimethoxysilane （KH-560） as a coupling reagent for high-performance liquid chromatography. Its chemical structure was characterized by Fourier infrared spectroscopy, elemental analysis, thermal thermogravimetry and 13C cross polarization/magic angle spinning nuclear magnetic resonance （CP/MAS NMR）. The chromatographic property of QUSP was systematically evaluated by using neutral, basic and acidic aromatic com- pounds as probes. In order to clarify its retention mechanism, a comparative study of QUSP with conventional oc- tadecylsilyl-bonded stationary phase （ODS） was also carried out under the same conditions. The results showed that the new quercetin-bonded phase exhibited an excellent reversed-phase chromatographic property with relatively weak hydrophobicity. However, it has an advantage over ODS in the fast separation of polar aromatic compounds because the quercetin ligand could provide various sites besides hydrophobicity, such as hydrogen bonding, dipole-dipole, n-n staking and charge transfer interactions. QUSP was performed in the baseline separations of ion- ized polar basic or acidic compounds, including pyridines, anilines, pyrimidines, purines and phenols with symmet- ric peak shape in common mobile phases without buffer salt within relatively short time. The natural ligands from herbs are readily available and contain a variety of active sites, which facilitate the exploration of industrial chromatographic separation materials for green products.

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.

通腑泻下颗粒指纹图谱的建立及7种成分的定量分析

建立通腑泻下颗粒(TongFu XieXia Granules,TFXXG)的高效液相色谱(HPLC)指纹图谱,并同时测定大黄素、大黄酚、大黄酸、芦荟大黄素、大黄素甲醚、厚朴酚以及和厚朴酚的含量。采用Waters Symmetry C18(2.1 mm×150 mm,3.5μm)色谱柱,以0.1%磷酸水溶液(A)和甲醇(B)为流动相梯度洗脱;流速为0.4 mL/min;柱温为30℃;检测波长为254 nm;进样量为10μL。建立10批TFXXG的指纹图谱,并采用“中药色谱指纹图谱相似度评价系统”(2012版)计算相似度;测定大黄素、大黄酚、大黄酸、芦荟大黄素、大黄素甲醚、厚朴酚以及和厚朴酚的含量。结果表明,10批TFXXG共确定出25个共有峰,相似度均在0.950以上;共指认出12个共有峰,分别为芥子碱硫氰酸盐、咖啡酸、松果菊苷、柚皮苷、新橙皮苷、芦荟大黄素、大黄酸、厚朴酚、和厚朴酚、大黄酚、大黄素以及大黄素甲醚。其中,芦荟大黄素、大黄酸、厚朴酚、和厚朴酚、大黄素、大黄酚以及大黄素甲醚的含量分别为0.1244~0.1304、0.4271~0.4387、3.0479~3.0853、1.2910~1.3039、0.2427~0.2523、0.7718~0.7897和0.5085~0.5249 mg/g。本文所建指纹图谱和定量分析方法重复性好,可操作性强,可用于控制TFXXG的质量。

纳米棒状MgO固相萃取结合高效液相色谱荧光法测定食用油中的苯并[a]芘

采用直接沉淀法合成了一种纳米棒状Mg O吸附剂,结合固相萃取-高效液相色谱荧光检测(SPE-HPLC/FLD)建立了食用油中苯并[a]芘(Ba P)的快速分析方法。采用X射线衍射(XRD)、傅里叶变换红外光谱(FTIR)、扫描电子显微镜(SEM)、比表面积和孔径分析仪(BET)对合成的棒状Mg O进行了表征,结果表明Mg O纳米材料是多晶立方结构,呈棒状形貌,具有较大的比表面积,非常适合作为SPE的吸附剂。对SPE过程中吸附剂用量、清洗液种类、解吸液种类及用量、上样液体积进行了详细的优化。在优化的条件下,食用油中Ba P在0.5~20.0μg/kg浓度范围内,线性方程回归系数的平方(R^(2))为0.9999,以信噪比的3倍和10倍计算方法检出限和定量限分别为0.10μg/kg和0.33μg/kg。同时,Ba P在低、中、高3种加标浓度下回收率在85.3%~96.5%,日内日间相对标准偏差范围在2.3%~9.0%,表明本方法具有很好的准确度和精密度。最后,将该方法应用于8种实际油样中Ba P的分析,所有样品的回收率在77.8%~92.5%之间,相对标准偏差小于9.8%,表明该方法具有很好的适用性,在实际样品分析中具有很好的应用前景。

Determination of Ciprofloxacin in Human Plasma and Urine by Precolumn Derivatization High Performance Liquid Chromatography with Fluorescence Detection

A sensitive, simple and selective high-performance liquid chromatographic （HPLC） method was developed for the determination of ciprofloxacin in biological fluids. The method is based on the reaction between the drug and 4-chloro-7-nitrobenzofurazan （NBD-C1） in borate buffer of pH 9.0 to yield a highly fluorescent derivative that is measured at 535 nm after excitation at 464 nm. The calibration curves were linear over the concentration ranges of 25--3000 and 50--3000 ng·mL -1 for plasma and urine, respectively. The mean recovery of ciprofloxacin from plasma and urine was 98.37% and 98.40%, respectively. The method was found to be sensitive, precise, accurate, and reproducible. All of the validation parameters were within the acceptance range.

柱前衍生法-HPLC测定化妆品中甲醛的不确定度评定

分析柱前衍生法-HPLC测定化妆品中甲醛的不确定度。根据《化妆品安全技术规范》(2015年版)第四章理化检验4.12方法甲醛测定和JJF1059.1-2012《测量不确定度评定与表示》,建立分析柱前衍生法-高效液相色谱法测定甲醛的不确定度数学模型,通过对整个测定过程中的不确定度来源进行分析和合成,运用最小二乘法对甲醛标准曲线拟合不确定度进行评定。取样量为0.2 g时,置信区间为95%时,K=2,化妆品中甲醛含量为(14.9±0.072104)mg/g。

高效液相-蒸发光散射检测器(HPLC-ELSD)测定红参中的精氨酸单糖苷(AF)及精氨酸双糖苷(AFG)含量

目的建立一种同时测定人参加工品中精氨酸单糖苷(AF)和精氨酸双糖苷(AFG)含量的方法。[方法]用PrevailTMC18column(4.6 mm×250 mm,5μm)色谱柱进行检测。流动相A:色谱乙腈,流动相B:5.0mmol/L七氟丁酸的0.7%三氟醋酸溶液。色谱条件为[0%A(0 min);0%A(5 min);15%A(8 min);35%A(25 min)];流速0.8 mL/min;漂移管温度为115℃;气体流量3.2 L/min。[结果]AF和AFG的检测限分别为0.015和0.010 mg/mL;线性关系相关系数分别为,AF:0.9997,AFG:0.9999,表明线性关系良好。AF和AFG检测的精密度,重复性,稳定性以及回收率的相对标准偏差分别为0.43%&0.37%,0.43%&0.55%,0.43%&0.49%,0.45%&0.15%。AF和AFG检测的回收率分别为99.5%&100%,表明方法稳定。经检测,高丽红参,中国红参和生晒参中AF含量分别为0.74%,0.91%和1.14%,AFG含量分别为6.69%,5.12%和0.85%。[结论]这种方法成功用于高丽红参,中国红参及生晒参中AF及AFG的检测;且红参中AF和AFG含量明显高于生晒参。该方法测定结果可靠,缩短了测定时间,较少杂质干扰。但因为本研究考察氨基酸种类较少,当衍生物种类较多时,仍需进一步考察其分离度。

现代分析技术在食品分析检测过程中的应用

食品分析与检测是确保食品安全性、营养价值和合规性的关键过程,涵盖营养成分、添加剂和污染物的识别与量化。本文探讨了食品分析的基本原理,包括样品采集、处理和不同分析方法,以及现代分析技术如高效液相色谱技术、气相色谱技术、质谱技术等在食品安全评估和质量控制中的应用,旨在提高食品分析检测的灵敏度和准确性,维护食品安全和提高公众健康水平。

基于UPLC-Q TOF-MSE技术的藤黄健骨丸指纹图谱建立及共有峰鉴定

建立藤黄健骨丸高效液相色谱(HPLC)指纹图谱,完善产品质量标准。采用Waters Symmetry C18(150 mm×2.1 mm,3.5μm)色谱柱;流速为0.4 mL/min;进样量为2μL;紫外检测波长为260 nm;在柱温30℃下以0.1%甲酸水(A)和0.1%甲酸乙腈(B)为流动相进行梯度洗脱。利用“中药色谱指纹图谱相似度评价系统(2012版本)”建立藤黄健骨丸指纹图谱,并分析相似度。采用液质联用技术(UPLC-Q TOF-MSE),根据化合物串联质谱信息结合对照品进行了共有峰结构鉴定。共确定了10批藤黄健骨丸指纹图谱中20个共有峰,相似度均在0.95以上。基于对照品和串联质谱信息指认了共有峰中13种成分的结构,并进行了峰归属。对10批藤黄健骨丸指纹图谱共有峰的相对保留时间和相对峰面积进行了计算,结果显示各批次样品共有峰的相对保留时间和相对峰面积均比较稳定,表明它们所对应的各成分含量较为均一。采用该指纹图谱对中间体进行了相似度评价,发现中间体与成品相关性良好。该方法精密度、重复性和稳定性好,不仅可用于藤黄健骨丸成品的质量控制,还可对中间体进行检测,用于生产过程的控制。