Determination of atmospheric hydroxyl radical by HPLC coupled with electrochemical detection

The hydroxyl radical （·OH） plays a central role in the oxidation and removal of many atmospheric compounds. Measurement of atmospheric ·OH is very difficult because of its high reactivity and low atmospheric abundance. In this article, a simple and highly sensitive method, high performance liquid chromatography coupled with coulometric detection （HPLC-CD）, was developed to determine ·OH indirectly by determining its reaction products with salicylic acid （SAL）, 2,3-dihydroxybenzoic acid （2,3-DHBA）, and 2,5-dihydroxybenzoic acid （2,5-DHBA）. Under the optimum conditions for its determination, 2,3-DHBA and 2,5-DHBA could be well separated and the detection limits for 2,3-DHBA were 3 ×10^-10 mol/L and for 2,5-DHBA were 1.5 ×10^-10 mol/L, which were lower than most previous reports. This method was also applied to measure atmospheric hydroxyl radical levels and demonstrated the feasibility in clean and polluted air.

Identification of Aflatoxigenic Fungi and Detection of Their Aflatoxin in Red Chilli (<i>Capsicum annuum</i>) Samples Using Direct Cultural Method and HPLC

Aflatoxins are the potential lethal toxin produced by Aspergillus sp. important health hazard throughout the world. In this study, 26 Aspergillus sp. have been isolated from 50 samples of red chilli collected throughout the country. These 26 isolates were grown primarily on agar media to identify the aflatoxin producing species. It is possible to distinguish A. flavus strains from other Aspergillus sp. developing orange colour on the reverse of the plates. The Coconut Cream Agar (CCA) is used to detect aflatoxin producer strains having blue fluorescence when exposed to a UV-light. Several other media were used for morphological characteristics of Aspergillus sp. Out of 26 isolates, four isolates were confirmed as Aspergillus sp. These isolates were subjected to cross contamination with freshly ground, sterile maize and after 15 days of incubation the contaminated maize were analyzed by HPLC and found aflatoxin in each of the sample containing 186 ppb (max.). This study was conducted to assay the ability to produce aflatoxins by the Aspergillus spp. isolated from red chilli (Capsicum annuum L. Solanaceae) available throughout the country. The results found in the experiment are much more behind the acceptable limit according to some international standard. As red chilli is a widely used spice in Bangladesh, the proper controlling measures may be taken for controlling the surveillance of aflatoxinic fungi like as use of bio-pesticides, proper drying method and storage conditions.

Detection of Praziquantel Content in Praziquantel Injection by HPLC

[ Objective] To detect the praziquantel content in praziquantel injection by HPLC. [ Methods ] Chromatographic conditions were as follows： chromato- graphic colmnn was Diamonsil Cls column （ 150 mm x 4.6 mm, 5 μm） ; column temperature was 25 ℃ ; mobile phase was acetonitrile-water （60：40） ; flow rate was 1.0 mL/min ; UV detection wavelength was 210 nm; and injection volume was 20 μL. [ Results ] Praziquantel showed good linear relationship within the con- centration of 6.037 - 90.55 g/L （ r = 0. 999 4） ; the average recovery rate was 99.24%, and RSD was 0. 769%. [Condusions ] This method was simple, rap- id, sensitive and repeatable, and could be used for the quality control of praziquantel injection.

New HPLC Method with Experimental Design and Fluorescence Detection for Analytical Study of Antihypertensive Mixture,Amlodipine and Valsartan

New HPLC method was developed for determination of amlodipine and valsartan in their binary mixture as a part of routine control of combined formulations. The method was validated to meet official requirements including selectivity, stability, linearity, precision and accuracy. Chromatography was carried out using a LiChrospher RP-18 column, a mixture containing acetonitrile, phosphate buffer of pH 3.5 and methanol (45:45:10, v/v/v) and new fluorescence detection at 255 nm for excitation and 448 nm for emission. The effect of methanol content, pH of the buffer, flow rate, detection wavelengths and column temperature was estimated in robustness study, according to a plan defined by the Plackett-Burman design. For identification of significant effects, both graphical and statistical methods were used. Ro-bustness for dissolution test was checked estimating the effects of paddle speed, temperature and pH of dissolution medium. The method was proved to complying with all official guidelines. Therefore, it is suitable for determination of amlodipine and valsartan in their binary mixtures for different analytical and pharmaceutical purposes.

NON-AQUEOUS REVERSED PHASE HPLC WITH LOW-WAVELENGTH UV DETECTION FOR TRIGLYCERIDE ANALYSIS

Glycerides are first separated to classes of triglycerides(TGs), diglycerides(DGs) and monoglycerides(MGs) by normal phase HPLC on silica gel column. Individual triglyceride separation is then achieved by non-aqueous reversed phase(NARP) HPLC on C_(18) column with UV detection at 215nm.

RP-HPLC-荧光检测法测定小鼠脑组织中5种神经递质的含量

目的 建立一种定量分析脑组织中神经递质的方法。方法 采用反相高效液相色谱 -荧光检测法 ,测定小鼠脑组织中去甲肾上腺素 (NE)、多巴胺 (L -DA)、5 -羟色胺 (5 -HT)、5 -羟色胺酸 (5 -HTP)、5 -羟基吲哚乙酸 (5 -HIAA) 5种神经递质的含量。结果 由色谱图显示 5种成分完全分离。小鼠脑组织中的L -NE为 70 .0 5± 6 .2 8、LDA110 .33± 10 .5 6、5 -HT5 0 .12±6 .85、5 -HTP6 90 .4 4± 6 0 .2 1、5 -HIAA96 0 .98± 80 .72ng·g-1。结论 本方法简便、快速、准确 ,为临床监测及科研提供参考。

Optimization of Chromatographic Conditions for Detecting Ellagic Acid in Pomegranate Peels Using HPLC Method

[Objective] This study aimed to optimize the chromatographic conditions for detecting ellagic acid in pomegranate peels using HPLC method. [Method] By using 0.2 mg/ml ellagic acid standard solution, on the basis of single-factor experiment and orthogonal experiment, chromatographic conditions （mobile phase ratio, flow rate, col- umn temperature） for detecting ellagic acid using HPLC were optimized. Based on the optimal chromatographic conditions, the ellagic acid content in experimental pomegranate peels was determined. [Resull] The optimal chromatographic conditions for detecting ellagic acid in pomegranate peels using HPLC method are： 1.2% phos- phoric acid：acetonitrile=85：15, column temperature of 35 ℃, and flow rate of 1.0 ml/min. The linear regression equation of ellagic acid is： y=2.9e＋0.6x＋4.4e＋5 （FF=9 999）. Ac- cording to the standard addition recovery test, the average recovery rate of ellagic acid is 98.20%, and RSD is 0.60%. Under above optimized chromatographic condi- tions, ellagic acid can be well separated from other interfering components in pomegranate peels, with shorter peak time and ideal effect, which is convenient for the detection in production practices. [Conclusion] This study laid the foundation for detecting ellagic acid in pomegranate peels using HPLC method.

RP-HPLC荧光检测法同时测定血浆中的盐酸维拉帕米和活性代谢物去甲维拉帕米的浓度

目的 研究建立同时测定盐酸维拉帕米 (Ver)和活性代谢物去甲维拉帕米 (Nor)血药浓度的方法。方法 应用反相高效液相 荧光检测色谱法 ,采用加洛帕米 (Gal)作内标 ,流动相组成为醋酸钠缓冲液 (pH =3.0 ,0 .0 1mol·L-1) 乙腈 三乙胺 (70∶35∶0 .4) ,荧光检测波长λex2 75nm ,λem310nm ,血浆样品提取方法采用碱化后有机相间液 液萃取 ,再酸化后反提。结果 Ver,Nor及Gal的色谱峰分离效果好 ,无内源性杂峰及Ver其它代谢产物干扰。结论 本研究建立了一种快速、准确。

RP-HPLC法测定人血浆中扎来普隆浓度

目的:建立测定人血浆中扎来普隆浓度的反相高效液相色谱法。方法:血浆样品中加入内标β-萘酚后用乙酸乙酯提取。固定相为Supelcosil C8色谱柱(250 mm ×4.6 mm,5μm),流动相为0.04 mol·L-1磷酸二氢钾缓冲液-乙腈(6:5,含三乙胺0.3%,磷酸调至pH 5.0),流速为1.0 mL·min-1。荧光检测:荧光激发波长345nm,发射波长460 nm。结果:本方法线性范围为1-128 ng·mL-1(r=0.9995),最低检测浓度为0.2 ng·mL-1,提取回收率为87.4%-91.9%,方法回收率为98.8%-100.8%,日内RSD为2.9%-5.4%,日间RSD为3.8%-13.3%。结论:本法简便、准确,适用于扎来普隆药代动力学的研究。

RP-HPLC测定牡丹皮饮片中3种活性成分的含量

目的：建立同时测定中药饮片牡丹皮中没食子酸、芍药苷和丹皮酚3种有效成分含量的反相高效液相色谱分析方法。方法：采用YMC—C18柱，以甲醇-0．05％磷酸为流动相，梯度洗脱，针对不同类型组分，实行分段变波长检测，以外标法定量。结果：没食子酸、芍药苷和丹皮酚的线性范围分别为0．0130～0．267，0．0880—1．76，0．164—3．28μg；平均加样回收率分别为104．3％，101．7％，99．5％。结论：本方法准确可靠，重复性好，回收率高，适用于丹皮及其制剂的质量分析。

RP-HPLC测定桑寄生及其寄主植物黄皮树盐酸小檗碱的含量

目的：测定桑寄生及其寄主植物中盐酸小檗碱的含量，研究寄主植物对桑寄生药材质量的影响。方法：采用甲醇一盐酸（100：1）溶液超声提取样品中的盐酸小檗碱，并采用RP—HPLC法进行含量测定，选用AgilentC18柱（250mmx4．6mm，5μm），流动相：乙腈：水：磷酸：三乙胺（72：28：0．01：0．05），流速：1．0mL·min-1，柱温：室温，检测波长：284nm。结果：不同寄主植物黄皮树及其桑寄生中盐酸小檗碱含量范围分别为0．14～7．58mg·g-1和0．11—1．35mg·g-1，桑寄生盐酸小檗碱含量最高可达到其寄主植物黄皮树盐酸小檗碱含量的132．10％。结论：寄主植物是影响桑寄生药材质量的关键，寄主植物不同桑寄生药材化学成分含量也不同。

RP-HPLC法测定三相避孕片含量和含量均匀度的研究

建立的三相避孕片的反相高效液相色谱测定法，能同时测定炔雌醇和左旋甲基炔诺酮的含量。 用 Ｃ１８ 柱，检测波长 ２２０ｎｍ ，流动相为甲醇水（７０∶３０）。炔雌醇的回收率为 ９９．５３％ ， Ｒ Ｓ Ｄ 为１１５％ ，左旋甲基炔诺酮的回收率为 ９９７１％ ， Ｒ Ｓ Ｄ 为 １８７％ 。该方法准确、灵敏、简便、快速。

RP-HPLC法检测CN_(10)蛋白的PEG化修饰率及含量

目的建立一种简单有效的测定CN10蛋白PEG化修饰率的方法 ,用于PEG化修饰工艺中的质量控制。方法采用反相高效液相色谱(RP-HPLC)法,以TSKgel Octadecyl-4PW作为色谱分离柱,以含0.12%三氟乙酸(TFA)、5%乙腈的水溶液作为A相溶液,以含0.1%TFA的乙腈作为B相溶液,在50℃柱温条件采用分段线性洗脱的方式分离蛋白,并考察CN10蛋白以及PEG化修饰后CN10蛋白的量效关系,根据外标法检测CN10和CN10-PEG的蛋白含量,根据PEG化修饰前后CN10蛋白量效关系的变化推断CN10蛋白的PEG化修饰率。结果 PEG化修饰前后的CN10蛋白经TSKgel Octadecyl-4PW色谱柱层析均能达基线分离,当用214 nm波长检测时,CN10蛋白浓度以及PEG修饰后的CN10蛋白均与其对应峰面积呈现良好的线性关系(r2=0.999 58;r2=0.999 67)。结论建立了一种简单快速的检测CN10蛋白PEG化修饰率的方法 ,此方法具有较高的准确性及专属性,可用于CN10的PEG化修饰工艺的监测。

Determination of Diphenytriazol (DL111-IT) in Rabbit Plasma by High-Performance Liquid Chromatography with Fluorescence Detection

Aim To develop an HPLC method with fluorescence detection for the assay ofDL111-IT in rabbit plasma. Methods DL111-IT and internal standard glybenzcyclamide in rabbit plasmawere extracted with chloroform. The determination was performed on a Diamonsil ODS-C_(18) column(150 mm x 4.6 mm, 5 μm) with a mobile phase of acetonitrile and 0.025 mol·L^(-1) diammoniumhydrogen phosphate buffer (pH 5.0, adjusted by phosphoric acid) (60:40, V/V) at a flow-rate of 1.0mL·min^(-1) . Fluorescence detector was operated at excitation wavelength of 250 nm and emissionwavelength of 332 nm. Results The calibration curve in plasma was linear from 1.00 - 20.00ng·mL^(-1) ( r = 0.999 6, n = 5). The method afforded average extracting recoveries of 85.3% ±1.3%, 84.9% ± 2.7% and 85.8% ± 1.8%, and the average method recoveries were 99.5% ±0.4%, 102.1%± 1.8% and 101.3% ± 2.4% for the high (20.00 ng·mL^(-1)) , middle (10.00 ng·mL^(-1)) and low (1.00 ng·mL^(-1)) check samples, respectively. The intra-day (n = 5) and inter-day (n = 5) precisions(RSD) were less than 3.0% and 7.0%, respectively. The limit of detection and quantitation for themethod were 0.3 ng·mL^(-1) (S/N = 3) and 1 ng·mL^(-1) (S/N = 10, RSD<7.0%) plasma sample,respectively. Conclusion The developed method was accurate, sensitive, simple and could be used forpharmacokinetic study of DL111- IT.

RP-HPLC荧光检测法测定大鼠血浆中甲磺酸二氢麦角毒碱浓度

目的:建立测定大鼠血浆中甲磺酸二氢麦角毒碱的反相高效液相荧光检测方法。方法:血浆样品预处理采用乙腈直接沉淀法去除蛋白质。采用 L-7000型高效液相色谱仪,Phenomenex C_(18)柱(250 mm×4.6 mm,5μm);流动相为水-乙腈-三乙胺(32:18:1),流速为1.1 mL·min^(-1);荧光检测波长:λ_(Ex)=290 nm,λ_(Ex)=348 nm;柱温:30℃;进样量:50μL。外标法峰面积定量。结果:血浆中甲磺酸二氢麦角毒碱能得到较好的分离,无明显的干扰峰。测定方法在1.0～200.0 ng·mL^(-1)范围内具有良好的线性关系,方法回收率为96.2%～100%,日内、日间 RSD 均小于15%,最低检测浓度为1.0 ng·mL^(-1),最低检测限为50 pg。结论:本法灵敏、准确、快速,适用于甲磺酸二氢麦角毒碱鼻腔喷雾剂的药物动力学和生物利用度的研究。

RP-HPLC荧光法测定鼻腔给药后大鼠血浆中雌二醇的浓度

目的:建立测定大鼠血浆中雌二醇的 RP-HPLC 荧光检测法。方法:以对羟基苯甲酸乙酯为内标,血浆样品经乙醚提取,50℃氮气吹干,甲醇复溶后,离心,取上清液进行 HPLC 测定。色谱柱为 Kromasil ODS C_(18)色谱柱(250 mm×4.6 mm,5μm,Zirchrom),流动相为乙腈-水(40:60,v/v),流速为1 mL·min^(-1);荧光的激发波长为267 nm,发射波长为302 nm;检测温度为25℃。结果:血浆样品在1.984～496.0 ng·mL^(-1)范围内线性关系良好,方法回收率(n=3)为96.98%～98.33%(RSD 为1.1%～2.7%),日间和日内精密度 RSD 均小于3.0%,检测限为30 pg。结论:本法简便、准确、重复性好,用于大鼠血浆中雌二醇浓度的测定取得良好的结果。

RP-HPLC法检测炎可宁片中土大黄苷方法的探讨

目的建立炎可宁片中土大黄苷的检测方法。方法采用RP-HPLC法。Kromasil C18柱,流动相:甲醇-乙腈-水(30∶8∶62),流速:1.0mL.min-1;检测波长:320nm。结果检测17批不同厂家的样品,其中,有10批次为阳性,其余7批次为阴性。结论本方法简便快捷,重复性好,可用于炎可宁片中土大黄苷的检测。

生物酶法合成氰氟草酯过程监测的RP-HPLC分析方法的研究

为实时监控化学-酶法制备氰氟草酯反应过程,建立了一种该体系中氰氟草酯的RP-HPLC的检测方法。采用SymmetryC18柱（5μm,4.6 mm i.d.×150 mm）,以V（甲醇）∶V（水）=80∶20为流动相,流速为1.0 mL/min,紫外检测波长为282 nm,柱温为30℃,进样量为20μL。氰氟草酯在5.0~1000.0 mg/L范围内线性良好,相关系数达到0.9999,检出限为1.0 mg/L,相对标准偏差为0.58%（n=5）,加标回收率在92.3%~101.5%之间。

Determination of Trace Amounts of Cobalt and Copper by High Performance Liquid Chromatography with Indigo Carmine Chemiluminescence Detection

A post-column reaction chemiluminescence detection method in ion chromatography is described in this paper.The chemiluminescence system was indigo cramine-hydrogen peroxide. The chemiluminescence reaction conditions and the separation conditions of Co and Cu in chromatography were presented.The detection limits were 1.0 and 2.0×10-8 g/mL for Co and Cu respectively.

HPLC-DAD测定饲用酸化剂苯甲酸中7种邻苯二甲酸类杂质

为了建立高效液相色谱法测定饲用酸化剂苯甲酸中邻苯二甲酸、2-羟基苯甲酸、3-羟基苯甲酸、4-羟基苯甲酸、2-甲基苯甲酸、3-甲基苯甲酸和4-甲基苯甲酸共7种邻苯二甲酸类杂质的方法。本试验将酸化剂样品溶于甲醇和初始流动相的混合溶液中,采用Agilent ZORBAX SB-C18色谱柱(4.6 mm×250 mm,5.0μm)分离7种邻苯二甲酸类杂质,以水-乙腈-甲基磺酸(85-15-0.1)和乙腈为流动相进行梯度洗脱,流速为1.2 mL/min,采用二极管阵列检测器(DAD),采集波长范围为210~400 nm,记录扫描光谱图和235 nm波长处的色谱图。用外标法定量邻苯二甲酸类杂质的含量。结果显示,7种邻苯二甲酸类杂质的浓度在0.10~40.00μg/mL范围内的线性良好,平均加标回收率在98.5%~102.7%范围内,相对标准偏差(RSD,n=5)介于0.3%~1.5%,检测限和定量限均为4 mg/kg。本试验建立的酸化剂苯甲酸中7种邻苯二甲酸类杂质的高效液相色谱-二极管阵列检测器(HPLC-DAD)检测方法快速且准确,可用于苯甲酸中7种邻苯二甲酸类杂质的定性和定量检测。