Development and validation of an RP-HPLC method for quantitative determination of vanillin and related phenolic compounds in Vanilla planifolia

A simple and fast method was developed using RP-HPLC for separation and quantitative determination of vanillin and related phenolic compounds in ethanolic extract of pods of Vanilla planifolia. Ten phenolic compounds, namely 4-hydroxybenzyl alcohol, vanillyl alcohol, 3,4-dihydroxybenzaldehyde, 4-hydroxybenzoic acid, vanillic acid, 4-hydroxybenzaldehyde, vanillin, p-coumaric acid, ferulic acid, and piperonal were quantitatively determined using ACN, methanol, and 0.2% acetic acid in water as a mobile phase with a gradient elution mode. The method showed good linearity, high precision, and good recovery of compounds of interest. The present method would be useful for analytical research and for routine analysis of vanilla extracts for their quality control.     

RP-HPTLC densitometric determination and validation of vanillin and related phenolic compounds in accelerated solvent extract of Vanilla planifolia*

A simple, fast and sensitive RP-HPTLC method is developed for simultaneous quantitative determination of vanillin and related phenolic compounds in ethanolic extracts of Vanilla planifolia pods. In addition to this, the applicability of accelerated solvent extraction (ASE) as an alternative to microwave-assisted extraction (MAE), ultrasound-assisted extraction (UAE) and Soxhlet extraction was also explored for the rapid extraction of phenolic compounds in vanilla pods. Good separation was achieved on aluminium plates precoated with silica gel RP-18 F(254S) in the mobile phase of methanol/water/isopropanol/acetic acid (30:65:2:3, by volume). The method showed good linearity, high precision and good recovery of compounds of interest. ASE showed good extraction efficiency in less time as compared to other techniques for all the phenolic compounds. The present method would be useful for analytical research and for routine analysis of vanilla extracts for their quality control.     

高效液相色谱法同时检测8种喹诺酮类兽药残留量

建立了吡哌酸、氧氟沙星、环丙沙星、单诺沙星、恩诺沙星、沙拉沙星、(噁)喹酸和氟甲喹8种喹诺酮类兽药残留量的高效液相色谱-荧光检测方法. 方法的线性范围: 30～2000 μg/kg, 定量限为30 μg/kg, 检出限为5 μg/kg (吡哌酸为20 μg/kg). 该方法采用基质分散和微波萃取技术进行样品的前处理, 回收率为70.0%～99.5%, 相对标准偏差1.0%～8.5%. 并同固相萃取方法进行了比较, 分别使用了RPS、HLB、MAX 3种固相萃取柱, 其回收率均低于本法. 确立了以Aglient XDB-C18 (5 μm, 150 mm×4.6mm i.d.)色谱柱, H3PO4-纯水-三乙胺-乙腈(pH 3.0)为流动相的最佳色谱条件, 吡哌酸、氧氟沙星、环丙沙星、单诺沙星、恩诺沙星、沙拉沙星的检测波长为: 激发波长285 nm, 发射波长460 nm;(噁)喹酸和氟甲喹为: 激发波长325 nm, 发射波长365 nm. 方法可满足兽药残留检测要求.     

高效液相色谱法快速测定生物样品中的视黄酸

建立了快速测定生物样品中全反式(all-trans-),9-顺式(9-cis-),13-顺式(13-cis-).视黄酸(RA)的高效液相色谱分析方法.经2次液-液萃取提取生物样品中的视黄酸后.直接应用高效液相色谱法同时测定了3种视黄酸同分异构体的含量.采用Waters C18反相柱(3.9×150mm),V(乙腈):V(0.1%冰醋酸溶液)=86:14为流动相,流速1.0 mL/min,柱温为25℃,检测波长为350 nm.3种视黄酸同分异构体的线性范围均为5-500 ng/mL,r2均大于0.999;检出限均为1 ng/mL;提取回收率为92.7%-101.8%,方法回收率为102,4%-104.4%;日内精密度小于8.3%,日间精密度小于11%.本方法适用于不同生物样品中视黄酸的定量研究.     

Simultaneous quantification of curcuminoids and xanthorrhizol in Curcuma xanthorrhiza by high-performance liquid chromatography

A new method for simultaneous quantification of curcuminoids and xanthorrhizol (XNT) in Curcuma xanthorrhiza was developed and validated using high-performance liquid chromatography with diode-array UV–Vis detector. The chromatographic separation was achieved on a Phenomenex C18 at room temperature with the mobile-phase acetonitrile ?0.001% formic acid in gradient elution system and delivered at a flow rate of 1?mL/min. Detection wavelength 425?nm was used for curcuminoids and 224?nm for XNT. System suitability, linearity, precision, accuracy, limit of detection, limit of quantitation, and stability were evaluated and were found in good agreement with Association of Official Analytical Chemists guidelines for single-laboratory validation. The proposed method was found to be precise, accurate, and reliable and also could be applied for the simultaneous quantitative analysis of curcuminoids and XNT in C. xanthorriza raw material and its herbal medicinal product.     

液相色谱串联四极杆质谱法同时测定婴幼儿配方食品中甲基香兰素和乙基香兰素

建立了混合阴离子交换固相萃取柱净化,液相色谱串联四极杆质谱法测定婴幼儿配方食品中甲基香兰素和乙基香兰素的方法.样品经水和乙腈提取,CuSO4溶液沉淀蛋白,NaOH调节pH,增加样品溶解性,阴离子交换固相萃取柱净化.目标化合物在梯度洗脱条件下经C18柱分离后采用ESI源负离子多反应监测模式进行检测.分别选取了婴幼儿配方乳...     

A simple method for nicardipine hydrochloride quantification in plasma using solid-phase extraction and reversed-phase high-performance liquid chromatography

A simple and sensitive reversed-phase liquid chromatography method was developed and validated for the determination of nicardipine hydrochloride (NC) in rabbit plasma. Nicardipine hydrochloride and nimodipine, used as internal standard, were initially extracted from plasma by a rapid solid-phase extraction using C(18) cartridges. After extraction, nicardipine hydrochloride was separated by HPLC on a C(18) column and quantified by ultraviolet detection at 254 nm. A mixture of acetonitrile-0.02 M sodium phosphate buffer-methanol (45:40:15) with 0.2% of triethylamine of pH of 6.1 was used as mobile phase. The mean (+/-SD) extraction efficiency of NC was 77.56 +/- 5.4, 84.23 +/- 4.32 and 83.94 +/- 3.87% for drug concentrations of 5, 25 and 100 ng/mL, respectively. The method proved to be linear in the range of 5-100 ng/mL with a regression coefficient of 0.9993. The relative standard deviations of intra- and inter-day analysis for NC in plasma were 3.26-6.52% (n = 5) and 4.71-9.38% (n = 5), respectively. The differences of the mean value measured from the concentration prepared, expressed in percentages (bias percentage), were only - 5.2, 0.4 and 0.8% at NC 5, 25 and 50 ng/mL, which confirmed the accuracy of the method. The analytical technique was used to determine NC plasma concentration after drug oral administration to rabbits. The results inferred that NC is rapidly absorbed in rabbits and has a short half-life (t(1/2) = 1.34 h).     

Simultaneous quantification of zidovudine and its glucuronide in serum by high-performance liquid chromatography

A sensitive high-performance liquid chromatography (HPLC) assay has been developed to simultaneously determine levels of the anti human immunodeficiency virus agent, zidovudine (AZT), and its major metabolite (the 5'-O-glucuronide) in serum. Samples were first mixed with an internal standard (a stereoisomer of AZT), then prepared for analysis using solid-phase extraction columns and chromatographed using a reversed-phase analytical column. Isocratic elution with a mobile phase of 15% acetonitrile, buffered to pH 2.70 with ammonium phosphate, gave good resolution of the three analytes and endogenous serum components. The HPLC analysis time required per sample was 34 min and analyte recoveries were reproducibly high (greater than 93%). Replicate analyses of prepared standards gave satisfactory precision and accuracy, with coefficients of variation less than 15% and deviations from expected concentrations less than 10%.     

Determination of tetracyclines residues in honey by on-line solid-phase extraction high-performance liquid chromatography

An automated system using on-line solid-phase extraction (SPE) high-performance liquid chromatography (HPLC) with ultraviolet (UV) detection was developed for the determination of tetracyclines (TCs), such as tetracycline (TC), oxytetracycline (OTC), chlortetracycline (CTC), metacycline (MC), and doxycycline (DC) in honey. One milliliter diluted honey sample was injected into a conditioned C18 SPE column and the matrix was washed out with water for 3 min. By rotation of the switching valve, TCs were eluted and transferred to the analytical column by the chromatographic mobile phase. Chromatographic conditions were optimized. TCs were separated in less than 8 min with a gradient elution using a mixture of 0.8% formic acid and acetonitrile. The UV detection was performed at 365 nm. The conditions for on-line SPE, including solvent and total time for loading sample and washing matrix were also optimized. Time for extraction and separation decreased greatly. For the five kinds of TCs, the limits of detection (LODs) at a signal-to-noise of 3 ranged from 5 to 12 ng g⁻¹. The relative standard deviations (R.S.D.) for the determination of TCs ranged from 3.4 to 7.1% within a day and ranged from 3.2 to 8.9% in 3 days, respectively.     

固相萃取-高效液相色谱检测葡萄酒中赭曲霉毒素A

使用C18小柱固相萃取, C18反相柱(250 mm×4.6 mm i.d.)分离,V(乙腈):V(水):V(乙酸)＝99:99:2为流动相,荧光检测器(激发波长333 nm,发射波长460 nm)检测,测定葡萄酒中赭曲霉毒素A.其质量浓度在6.25～200 ng/mL范围内呈良好线性,相关系数为0.9997.样品经浓缩60倍后,方法检出限为0.027 ng/mL.对红葡萄酒、干红及白葡萄酒进行了加标回收实验,回收率为80.1%～109.8%.平行7份样品加标回收率相对标准偏差为5.9%.对市售6种葡萄酒进行了赭曲霉毒素A的测定.     

Quantification of myrislignan in rat plasma by solid-phase extraction and reversed-phase high-performance liquid chromatography

A rapid and simple reversed-phase high-performance liquid chromatographic (RP-HPLC) method has been developed for determination of myrislignan in rat plasma after intravenous administration. The analytes extracted from plasma samples by solid-phase extraction were successfully carried out on a Diamonsiltrade mark ODS C(18) column (250 x 4.6 mm i.d., 5 microm) with an RP(18) guard column (8 x 4.6 mm i.d., 5 microm) and a mobile phase of MeOH-H(2)O (4:1, v/v). The UV detector was set at a single wavelength of 270 nm. The linear ranges of the standard curves were 0.5-30.0 microg/mL with the correlation coefficients greater than 0.9992. The lower limits of detection and quantification were 0.1 and 0.3 microg/mL for myrislignan. Intra- and inter-day precisions were 2.4-7.5 and 1.3-5.7%, respectively. The extraction recovery from plasma was more than 90%. This assay method has been successfully used to study the pharmacokinetics of myrislignan in rats.     

Determination of ethylenediaminetetraacetic acid in sea water by solid-phase extraction and high-performance liquid chromatography

The chelating agent EDTA is widely used, and as a result is showing up widely in the aquatic environment. Here we describe a preconcentration procedure for measuring EDTA concentration in sea water samples by HPLC. The procedure consists of forming an Fe(III) complex followed by solid-phase extraction using an activated carbon cartridge. After the preconcentration, EDTA was quantified by HPLC with ultraviolet detection (260 nm). The enrichment permitted the determination of EDTA at concentrations as low as 1 nM. Good recoveries were obtained for both brackish and full-strength sea water with high repeatability (RSD < 6%). The method was applied to sea water samples taken from near the mouth of the Oyabe River in Japan.     

Ultrafast UPLC‐ESI‐MS and HPLC with monolithic column for determination of principal flavor compounds in vanilla pods

In this study, two novel chromatographic methods based on monolithic column high‐performance liquid chromatography (HPLC) and ultra‐performance liquid chromatography (UPLC) were developed for the ultrafast determination of principal flavor compounds namely vanillin, vanillic acid, p‐hydroxybenzoic acid, and p‐hydroxybenzaldehyde in ethanolic extracts of Vanilla planifolia pods. Good separation was achieved within 2.5 min using Chromolith RP18e column (100 mm×4.6 mm) for HPLC and Acquity BEH C‐18 (100 mm×2.1 mm, 1.7 μm) column for UPLC. Both methods were compared in terms of total analysis time, mobile phase consumption, sensitivity, and validation parameters like precision, accuracy, LOD, and LOQ. Further, system suitability test data including resolution, capacity factor, theoretical plates, and tailing factor was determined for both the methods by ten replicate injections. Monolithic column based HPLC gave better results for most of the selected parameters while UPLC was found to be more eco‐friendly with low mobile phase consumption and better sensitivity. Both methods may be used conveniently for the high throughput analysis of large number of samples in comparison to traditional particulate column.     

Determination of fluoxetine and its N-desmethyl metabolite in human plasma by high-performance liquid chromatography

A rapid and sensitive high-performance liquid chromatographic method has been developed for the simultaneous determination of the antidepressant fluoxetine and its active metabolite norfluoxetine in human plasma using paroxetine as internal standard. After liquid-liquid extraction, the compounds were separated on a C18 column using as mobile phase acetonitrile and 40 mM potassium dihydrogen phosphate buffer (pH 2.3) in the ratio 31:69 (v/v). The quantification of fluoxetine and norfluoxetine was made by fluorescence detection at Ex/Em 230/312 nm. The assay for each analyte was linear over the ranges 1-39 and 0.9-36 ng/ml, respectively. For both compounds intra- and inter-day accuracy and precision ranged between −7.9-12.4 and 0.7-14.7%, respectively. The method was applied to the analysis of plasma samples obtained from healthy subjects treated with one single oral dose of 40 mg fluoxetine.     

高效液相色谱法测定硫酸沙丁胺醇

利用高效液相色谱仪-电子捕获检测器(HPLC-ECD)测定了市售片剂硫酸沙丁胺醇的含量.结果表明,利用HPLC-ECD技术测定硫酸沙丁胺醇的线性范围为0.944~33.8mg·L-1(r=0.999 6);回收率为99.0%~107.8%(RSD≤4.6%).该法可用于测定片剂的硫酸沙丁胺含量.     

Faster analysis by reversed-phase high-performance liquid chromatography

Summary Many analysts are not taking full advantage of the high speed possibilities of modern LC. Some analytical procedures reported in the literature, and many in regular use in control laboratories, could be achieved in less time without loss in precision. Some factors which affect retention times are discussed and the advantages and disadvantages of employing shorter column lengths and finer packing materials in reversed-phase HPLC are examined. The effect on efficiency of increased flow rates with 10,5 and 3 m ODS materials is shown. The ability to couple shorter column lengths without loss of efficiency is also demonstrated. This allows a minimum length to be selected that gives adequate resolution. Examples of high speed separations are shown and limitations in state of the art HPLC equipment and chromatographic data systems are discussed briefly.Presented at the 14th International Symposium on Chromatography London, September, 1982     

Determination of bisacodyl and its hydrolysis products in bisacodyl formulations by high-performance liquid chromatography

Summary Bisacodyl, its half-hydrolysed and fullyhydrolysed products can be determined specifically by high-performance liquid chromatography at 254 nm after separation on a C₁₈ reversed-phase column with a mixture of water-acetonitrile-sodium acetate as a mobile phase. Ten different bisacodyl preparations, enteric coated dragees and suppositories, were analysed and found to contain the hydrolysis products in the range of 0.1 to 1.67%. The detection limit was around 7.5 g/ml for hydrolysis products and about 15 g/ml for bisacodyl for an injected volume of 20 l. The coefficients of variation of the method for bisacodyl and hydrolysis products are 1.44 and 2.40%, respectively.

---

Bestimmung von Bisacodyl und seinen Hydrolyseprodukten in Bisacodylpräparaten durch HPLC

Zusammenfassung Es wird über eine hochdruckflüssigkeitschromatographische Methode zur Bestimmung von Bisacodyl und seinen beiden Zersetzungsprodukten, der halbverseiften- und der vollverseiften Ester berichtet. Die Bestimmung erfolgte auf einer C₁₈ Reversed-Phase Säule mit dem Fließmittel Wasser-Acetonitril-Natriumacetat bei 254 nm. Zehn bisacodylhaltige Präparate, magensaftresistente Dragees und Zäpfchen, wurden analysiert. Der Gehalt an den beiden Verseifungsprodukten lag zwischen 0,1 und 1,67%. Die Nachweisgrenze beträgt für das Bisacodyl ca. 15 (g/ml und für die beiden Verseifungsprodukte etwa 7,5 g/ml für die eingespritzten Volumina von 20 l. Als relative Standardabweichung der Methode wurde für Bisacodyl und die Hydrolyseprodukte 1,44 bzw. 2,4% ermittelt.

     

Determination of andrographolide and dehydroandrographolide in rabbit plasma by on-line solid phase extraction of high-performance liquid chromatography

The high-performance liquid chromatography (HPLC) coupled with on-line solid phase extraction (SPE) and ultraviolet (UV) detection was developed for determining andrographolide and dehydroandrographolide in rabbit plasma. Plasma samples (100 μL) were injected directly into a C18 SPE column and the biological matrix was washed out for 6 min using 15% aqueous methanol. By rotation of the switching valve, andrographolide and dehydroandrographolide were eluted in the back-flush mode and transferred to the analytical column by the chromatographic mobile phase consisted of methanol:acetonitrile (ACN):water (50:10:40; v/v). The UV detection was performed at 225 nm. The calibration curves showed excellent linear relationship (R ≥ 0.9993) over the concentration range of 0.05-5.0 μg mL⁻¹. The within- and between-day precisions (R.S.D.) of two analytes were in the range of 1.2-6.5% and the accuracies were between 92.0% and 102.1%. Their recoveries were all greater than 94%. The limits of detection were 0.019 μg mL⁻¹ for andrographolide and 0.022 μg mL⁻¹ for dehydroandrographolide. This method was successfully applied to the plasma concentration-time curve study after oral administration of Andrographis paniculata Nees extract in rabbit.     

Assay of naproxen by high-performance liquid chromatography and identification of its photoproducts by LC-ESI MS

A rapid, accurate and reliable reversed-phase high-performance liquid chromatographic (HPLC) method for the determination of naproxen and its photodegradation products in methanol was developed and validated. An Inertsil 5-ODS-3V column (5 microm, C18, 250 x 4.6 mm i.d.) was used with a mobile phase of acetonitrile-methanol-1% HOAc in H2O (40:20:40, v/v/v). UV detection was set at 230 nm. The developed method satisfies system suitability criteria, peak integrity and resolution for the parent drug and its photoproducts. The intraday and interday standard deviations of five replicate determinations for five consecutive days at the working concentrations of 5.0, 10, 25, 50, and 100 microm were 0.23-0.98 with coefficients of variance (CVs) of between 0.96 and 4.56% for the former, and 0.14-1.15 with CVs of between 1.13 and 3.82% for the latter. The percentage recoveries were determined to be 98.34, 99.19, 100.18, 102.97 and 99.81%, respectively, at the five concentrations between 5.0 and 100 microm. The limit of quantitation of naproxen was determined to be 0.29 microg/mL, while the detection limit was 64 ng/mL. Four major photoproducts were observed from the HPLC chromatogram using a Panchum PR-2000 reactor which equipped with 8 W x 16 low-pressure quartz mercury lamps as the light source for irradiation of a naproxen sample in methanol. The structures of the photoproducts were confirmed by LC-ESI MS.