Chemical fingerprint of Ganmaoling granule by double‐wavelength ultra high performance liquid chromatography and ultra high performance liquid chromatography with quadrupole time‐of‐flight mass spectrometry

A method incorporating double‐wavelength ultra high performance liquid chromatography with quadrupole time‐of‐flight mass spectrometry was developed for the investigation of the chemical fingerprint of Ganmaoling granule. The chromatographic separations were performed on an ACQUITY UPLC HSS C₁₈ column (2.1 × 50 mm, 1.8 μm) at 30°C using gradient elution with water/formic acid (1%) and acetonitrile at a flow rate of 0.4 mL/min. A total of 11 chemical constituents of Ganmaoling granule were identified from their molecular weight, UV spectra, tandem mass spectrometry data, and retention behavior by comparing the results with those of the reference standards or literature. And 25 peaks were selected as the common peaks for fingerprint analysis to evaluate the similarities among 25 batches of Ganmaoling granule. The results of principal component analysis and orthogonal projection to latent structures discriminant analysis showed that the important chemical markers that could distinguish the different batches were revealed as 4,5‐di‐O‐caffeoylquinic acid, 3,5‐di‐O‐caffeoylquinic acid, and 4‐O‐caffeoylquinic acid. This is the first report of the ultra high performance liquid chromatography chemical fingerprint and component identification of Ganmaoling granule, which could lay a foundation for further studies of Ganmaoling granule.     

Continuous intact cell detection and viability determination by CE with dual‐wavelength detection

We introduce here a method for continuous intact cell detection and viability determination of individual trypan blue stained cells by CE with ultraviolet–visible dual‐wavelength detection. To avoid cell aggregation or damage during electrophoresis, cells after staining were fixed with 4% formaldehyde and were continuously introduced into the capillary by EOF. The absorbance of a cell at 590 nm was used to determine its viability. An absorbance of two milli‐absorbance unit at 590 nm was the clear cut‐off point for living and dead Hela cells in our experiments. Good viability correlation between the conventional trypan blue staining assay and our established CE method (correlation coefficient, R²=0.9623) was demonstrated by analysis of cell mixtures with varying proportions of living and dead cells. The CE method was also used to analyze the cytotoxicity of methylmercury, and the results were in good agreement with the trypan blue staining assay and 3‐(4,5‐dimethyl‐2‐thiazyl)‐2,5‐diphenyl‐2H‐tetrazolium bromide methods. Compared with the 3‐(4,5‐dimethyl‐2‐thiazyl)‐2,5‐diphenyl‐2H‐tetrazolium bromide method, our established CE method can be easily automated to report cell viability based on the state of individual cells. Tedious manual cell counting and human error due to investigator bias can be avoided by using this method.     

Quality evaluation of Salvia miltiorrhiza Bge. by ultra high performance liquid chromatography with photodiode array detection and chemical fingerprinting coupled with chemometric analysis

An ultra high performance liquid chromatography with photodiode array detection method is developed for the simultaneous quantitative determination of five water‐soluble compounds including danshensu, protocatechualdehyde, rosmarinic acid, salvianolic acid B, and salvianolic acid A in Salvia miltiorrhiza Bge. samples. Through method optimization, the five compounds all expressed good linearity (R² > 0.9990) in a wide concentration range together with satisfactory accuracy, precision, and stability. Moreover, through qualitative analysis of the chemical fingerprint combined with similarity analysis, hierarchical cluster analysis, principle component analysis, and partial least‐squares discriminate analysis, we determined that the 13 batches of Salvia miltiorrhiza Bge. were similar in internal quality and the differences resulted from various cultivation environments, recovery elements, and others. Seen from the results of hierarchical cluster analysis and principle component analysis, the classification of 13 batches was in accordance, and partial least‐squares discriminate analysis technique was more suitable than the principle component analysis model to provide a distinct classification of test samples on the basis of their different components. Moreover, a permutation test verified the rationality of partial least‐squares discriminate analysis and variable importance plot showed that peaks 37 and 38 were the most significant variables in distinguishing the Salvia miltiorrhiza Bge. samples. The idea of the quantitative and qualitative analysis of Salvia miltiorrhiza Bge. was convenient, sensitive, and comprehensive, which could be applied to evaluate the quality of more traditional Chinese medicines.     

Molecularly imprinted solid‐phase extraction coupled with ultra high performance liquid chromatography and fluorescence detection for the determination of estrogens and their metabolites in wastewater

Estrogens are an important class of endocrine‐disrupting compounds, and their contamination of environmental waters through the effluents of wastewater treatment plants could have an important impact on aquatic biota, even at low concentrations. For this reason, the development of selective and sensitive extraction methodologies, which permit the identification and quantification of these compounds at trace level concentrations, is very important. In this study, a quantitative method based on molecularly imprinted solid phase extraction coupled to ultra high performance liquid chromatography with fluorescence detection has been developed. It has been used for the simultaneous determination of three estrogens and two of their metabolites in water samples from wastewater treatment plants. The method developed presents satisfactory limits of detection (between 0.18 and 0.45 ng·mL^?1), good recoveries (higher than 60%) and low relative standard deviations (under 10%). The method was used to analyze wastewater from a veterinary hospital as well as influent and effluent samples of a wastewater treatment plant of Gran Canaria (Spain) The concentrations of the detected hormones ranged from 1.35 to 2.57 ng·mL^?1.     

The determination of serum retinol by high performance liquid chromatography

A method for the quantitation of retinol in serum by normal phase high performance liquid chromatography is described. The mobile phase consists of a hexane/diethylether/methanol mixture with spectrophotometric detection. The sample preparation is similar to that described by other authors and involves protein precipitation followed by extraction and direct injection onto the chromatograph. Adequate sensitivity is achieved using 200 μl samples. The internal standard chosen is α-naphthol because of its spectral similarities to retinol and its greater stability than the commonly used retinyl esters. The method has been successfully applied to the clinical evaluation of a number of malabsorption syndromes for which it is preferred to the measurement of total carotenoids.     

Quantitative determination of low concentrations of DHETX m. s. in human plasma by high performance liquid chromatography with fluorescence detection

A method is described for separation of low amounts of DHETX m. s. from human plasma, based on extraction and determination by high performance liquid chromatography with fluorimetric detection.     

Multi‐component determination and chemometric analysis of Paris polyphylla by ultra high performance liquid chromatography with photodiode array detection

Multi‐source analysis of traditional Chinese medicine is key to ensuring its safety and efficacy. Compared with traditional experimental differentiation, chemometric analysis is a simpler strategy to identify traditional Chinese medicines. Multi‐component analysis plays an increasingly vital role in the quality control of traditional Chinese medicines. A novel strategy, based on chemometric analysis and quantitative analysis of multiple components, was proposed to easily and effectively control the quality of traditional Chinese medicines such as Chonglou. Ultra high performance liquid chromatography was more convenient and efficient. Five species of Chonglou were distinguished by chemometric analysis and nine saponins, including Chonglou saponins I, II, V, VI, VII, D, and H, as well as dioscin and gracillin, were determined in 18 min. The method is feasible and credible, and enables to improve quality control of traditional Chinese medicines and natural products.     

Quantitative determination of seven chemical constituents and chemo‐type differentiation of chamomiles using high‐performance thin‐layer chromatography

A simple and rapid high‐performance thin‐layer chromatographic method was developed for the separation and determination of six flavonoids (rutin, luteolin‐7‐O‐β‐glucoside, chamaemeloside, apigenin‐7‐O‐β‐glucoside, luteolin, apigenin) and one coumarin, umbelliferone from chamomile plant samples and dietary supplements. The separation was achieved on amino silica stationary phase using dichloromethane/acetonitrile/ethyl formate/glacial acetic acid/formic acid (11:2.5:3:1.25:1.25 v/v/v/v/v) as the mobile phase. The quantitation of each compound was carried out using densitometric reflection/absorption mode at their respective absorbance maxima after postchromatographic derivatization using natural products reagent (1% w/v methanolic solution of diphenylboric acid‐β‐ethylamino ester). The method was validated for specificity, limits of detection and quantification, precision (intra‐ and interday) and accuracy. The limits of detection and quantification were found to be in the range from 6–18 and 16–55 ng/band for six flavonoids and one coumarin, respectively. The intra‐ and interday precision was found to be <5% RSD and recovery of all the compounds was >90%. The data acquired from high‐performance thin‐layer chromatography was processed by principal component analysis using XLSTAT statistical software. Application of principal component analysis and agglomerative hierarchial clustering was successfully able to differentiate two chamomiles (German and Roman) and Chrysanthemum.     

Quantitative analysis of hydroxylated polymethoxyflavones by high‐performance liquid chromatography

Since the hydroxylated polymethoxyflavones were isolated from orange and other citrus peels, they have been found to exhibit potent anti‐cancer and anti‐inflammatory activities. Hydroxylated polymethoxyflavones, especially 5‐demethylnobiletin and 5‐hydroxy‐3,6,7,8,3′,4′‐hexamethoxyflavone, exert more potent activities than their counterpart polymethoxyflavones (PMFs). These findings have led to a new era of exploration of hydroxylated polymethoxyflavones and PMFs from the citrus genus for their potential application in nutraceutical, pharmaceuticals and functional foods. A practical and efficient analytical method for quantitatively characterizing the composition of PMFs has only recently been developed, and has applications both in academic research laboratories and quality controls. However, chemical analyses of the hydroxylated polymethoxyflavones have not been previously described. This paper reports the quantitative analysis of six 5‐demethylated PMFs in various commercial orange peel extracts, using high‐performance liquid chromatography with UV detection. Copyright © 2009 John Wiley & Sons, Ltd.     

李晶1,2, 徐济仓1, 李雪梅1, 周建光2, 朱岩3, 缪明明1*超高效液相色谱法同时测定香精香料中14种禁限用物质

建立了超高效液相色谱-二极管阵列检测器(UPLC-PDA)同时测定香精香料中14种禁限用物质的方法。样品经10%(v/v)甲醇水溶液(含1%(v/v)氨水)提取后进行UPLC测定。采用的色谱柱为Waters BEH C18柱(50 mm×2.1 mm, 1.7 μm),流动相为10 mmol/L乙酸铵(含0.1%乙酸)和乙腈,梯度洗脱,流速为0.2 mL/min,柱温为35 ℃,在200～500 nm范围内进行扫描检测。结果表明,该方法在12 min内可实现14种禁限用物质的分离和检测,在0.10～50 mg/L范围内具有较好的线性关系,各待测物的线性相关系数均大于0.995,检出限(以信噪比为3计)为0.32～2.51 mg/kg。在5、10、20 mg/L添加水平下待测物的平均回收率为93.0%～121.0%,相对标准偏差为0.51%～4.50%。该方法操作简易,灵敏度高,线性相关性好,重复性佳,可以满足国内对于香精香料样品中禁限用物质的检测要求。     

Online solid‐phase extraction with high‐performance liquid chromatography and mass spectrometry for the determination of five tannins in traditional Chinese medicine injections

A rapid analytical method based on online solid‐phase extraction with high‐performance liquid chromatography and mass spectrometry has been established and applied to the determination of tannin compounds that may cause adverse effects in traditional Chinese medicine injections. Different solid‐phase extraction sorbents have been compared and the elution buffer was optimized. The performance of the method was verified by evaluation of recovery (≥40%), repeatability (RSD ≤ 6%), linearity (r² ≥ 0.993), and limit of quantification (≤0.35 μg/mL). Five tannin compounds, gallic acid, cianidanol, gallocatechin gallate, ellagic acid, and penta‐O‐galloylglucose, were identified with concentrations ranging from 3.1–37.4 μg/mL in the analyzed traditional Chinese medicine injections.     

Chemical stability of midazolam injection by high performance liquid chromatography

The chemical stability of midazolam hydrochloride injection, undiluted or diluted with dextrose sterile solution, was studied at different storage conditions by LC. The study was performed at room temperature (23 +/- 2 degrees C) under light exposure and light protection, +8 +/- 1 degrees C and -20 +/- 0.5 degrees C, in glass and plastic containers over 14 days with midazolam hydrochloride injection, undiluted or diluted with 5% dextrose sterile solution. Chromatographic separation was carried out on a RP-18(e) column, using a mobile phase consisting of ACN-phosphate buffer (pH 3.3; 0.1 M) (30:70 v/v) at a flow rate of 1.0 mL/min and UV detection at 220 nm. The concentrations of all samples remained greater than 90% of the original concentration. The chromatographic assay exhibited an adequate linearity (r(2) >0.999), selectivity, precision (RSD <3.1), and accuracy (recoveries from 100.46 to 101.40%). Injectable midazolam hydrochloride was chemically stable in all conditions that were studied.     

Simultaneous determination of antiviral drugs in chicken tissues by ultra high performance liquid chromatography with tandem mass spectrometry

An ultra high performance liquid chromatography with tandem mass spectrometry method was established for the rapid and simultaneous analysis of seven antiviral drugs, amantadine, rimantadine, memantine, moroxydine, imiquimod, oseltamivir, and acyclovir, in chicken liver, muscle, and egg. Homogenized samples were extracted with trichloroacetic acid and acetonitrile solutions and then purified by cation‐exchange solid‐phase extraction. The target drugs were analyzed by liquid chromatography with a UPLC BEH Amide column (2.1 mm × 100 mm, 1.7 μm) coupled with a tandem mass spectrometer operating in the positive multiple‐reaction mode. A perfectly linear relationship was obtained within the concentration ranges of 0.5–20 μg/L for acyclovir and 0.1–10 μg/L for the other six antiviral drugs. The average recoveries of the seven antiviral drugs using four addition levels in chicken liver, muscle, and eggs were 82.67–90.10, 82.30–92.27, and 81.98–93.77%, respectively, and the acceptable coefficients of variation were 5.18–9.88, 4.84–11.2, and 42.8–9.95%, respectively. The detection limits and detection capabilities of the analysis method for the seven antiviral drugs were in the ranges of 0.04–0.64 and 0.11–0.78 μg/kg, respectively. Additionally, an inter‐laboratory study among five laboratories further validated the method.     

Evaluation of gardenia yellow using crocetin from alkaline hydrolysis based on ultra high performance liquid chromatography and high‐speed countercurrent chromatography

Gardenia yellow is globally the most valuable spice and food color. It is generally a mixture of water‐soluble carotenoid glycosyl esters which consist of crocetin bis(gentiobiosyl) ester as the main component. Crocetin is a natural carotenoid dicarboxylic acid that may be a candidate drug for pharmaceutical development, however, it is either present in trace amounts or is absent in natural gardenia yellow products. We here propose that crocetin produced by alkaline hydrolysis can be used to qualitatively evaluate gardenia yellow products using an ultra high performance liquid chromatographic assay. A useful and efficient isolation technique for isolating high‐purity crocetin from gardenia yellow using high‐speed countercurrent chromatography is described. High‐speed countercurrent chromatographic fractionation followed by an ultra high performance liquid chromatographic assay showed that trans‐crocetin is easily converted to about 15% cis‐crocetin (85% trans‐crocetin). Crocetin in gardenia yellow was quantitatively evaluated. Our approach is based on the hydrolysis process for converting crocetin glycosyl esters to crocetin before evaluation and isolation using the ultra high performance liquid chromatographic and high‐speed countercurrent chromatographic methods. The combination of hydrolysis and chromatographic methods allows evaluation of the purity and quantity of crocetin in gardenia yellow.     

饮料中4种人工合成甜味剂同时测定的超高效液相色谱快速检测方法

建立了采用超高效液相色谱同时测定饮料中4种甜味剂(安赛蜜、糖精钠、甜味素、纽甜)的方法。样品经简单的预处理后,通过ACQUITY UPLCTM BEH C18色谱柱分离,以乙腈-20 mmol/L磷酸二氢钠水溶液为流动相进行梯度洗脱,于220 nm波长下紫外检测。一次进样分析仅需6 min。4种甜味剂在0.5～20.0 mg/L范围内的线性关系良好,在加标水平为1,10和20 mg/L时,被测物的回收率为80.5%～95.2%,相对标准偏差为0.50%～8.7%。     

Synthesis of monodisperse silica microspheres and modification with diazoresin for mixed‐mode ultra high performance liquid chromatography separations

Monodisperse silica particles with average diameters of 1.9–2.9 μm were synthesized by a modified Stöber method, in which tetraethyl orthosilicate was continuously supplied to the reaction mixture containing KCl electrolyte, water, ethanol, and ammonia. The obtained silica particles were modified by self‐assembly with positively charged photosensitive diazoresin on the surface. After treatment with ultraviolet light, the ionic bonding between silica and diazoresin was converted into covalent bonding through a unique photochemistry reaction of diazoresin. Depending on the chemical structure of diazoresin and mobile phase composition, the diazoresin‐modified silica stationary phase showed different separation mechanisms, including reversed phase and hydrophilic interactions. Therefore, a variety of baseline separation of benzene analogues and organic acids was achieved by using the diazoresin‐modified silica particles as packing materials in ultra high performance liquid chromatography. According to the π–π interactional difference between carbon rings of fullerenes and benzene rings of diazoresin, C₆₀ and C₇₀ were also well separated by ultra‐high performance liquid chromatography. Because it has a small size, the ∼2.5 μm monodisperse diazoresin‐modified silica stationary phase shows ultra‐high efficiency compared with the commercial C₁₈‐silica high‐performance liquid chromatography stationary phase with average diameters of ∼5 μm.     

Comparison of ultra high performance supercritical fluid chromatography,ultra high performance liquid chromatography,and gas chromatography for the separation of synthetic cathinones

A comparison of ultra high performance supercritical fluid chromatography, ultra high performance liquid chromatography, and gas chromatography for the separation of synthetic cathinones has been conducted. Nine different mixtures of bath salts were analyzed in this study. The three different chromatographic techniques were examined using a general set of controlled synthetic cathinones as well as a variety of other synthetic cathinones that exist as positional isomers. Overall 35 different synthetic cathinones were analyzed. A variety of column types and chromatographic modes were examined for developing each separation. For the ultra high performance supercritical fluid chromatography separations, analyses were performed using a series of Torus and Trefoil columns with either ammonium formate or ammonium hydroxide as additives, and methanol, ethanol or isopropanol organic solvents as modifiers. Ultra high performance liquid chromatographic separations were performed in both reversed phase and hydrophilic interaction chromatographic modes using SPP C18 and SPP HILIC columns. Gas chromatography separations were performed using an Elite‐5MS capillary column. The orthogonality of ultra high performance supercritical fluid chromatography, ultra high performance liquid chromatography, and gas chromatography was examined using principal component analysis. For the best overall separation of synthetic cathinones, the use of ultra high performance supercritical fluid chromatography in combination with gas chromatography is recommended.     

Simultaneous determination of 20 food additives by high performance liquid chromatography with photo-diode array detector

An efficient and accurate analytical method was developed for the simultaneous determination of 20 synthetic food additives, including three sweeteners,seven food colorants,nine synthetic preservatives and caffeine,by high performance liquid chromatography (HPLC) with photodiode array detector(PDA).This method permits the detection of food additives at very low concentrations(0.005-0.150μg/mL).The applicability was verified by the determination of food additives present in various foodstuffs.     

高效液相色谱法定量分析奥曲肽

建立奥曲肽的高效液相色谱定量分析方法。色谱柱为Eclipse plus C18柱(4.6 mm×250 mm,5 μm),流动相为乙腈-0.25%高氯酸水溶液(体积比为30∶70),流量为1.0 mL/min,检测波长为210 nm,柱温为25℃。奥曲肽的质量浓度在4.38~219 μg/mL范围内与色谱峰面积成良好的线性关系,相关系数为0.9999,检出限为1.1 ng,定量限为2.19 ng。测定结果的相对标准偏差为0.26%~0.46% (n=5),加标回收率为97.41%~100.26%。该方法简便、快速、准确,适用于奥曲肽原料药与制剂的定量分析。