Efficient recovery of electrophoretic profiles of nucleoside metabolites from urine samples by multivariate curve resolution

Chemometric techniques usually employed in purity assessment and resolution of multicomponent peaks have been applied to analytical data from complex biological samples obtained with CE‐DAD. In the assessment of the purity of the electrophoretic peaks, the orthogonal projection approach, the orthogonal projection approach with Durbin–Watson criterion, and the simple‐to‐use interactive self‐modeling mixture analysis method have been employed. Multivariate curve resolution with alternating least squares has been successfully implemented to resolve co‐migrating peaks of metabolites in CE‐DAD and to recover qualitative and quantitative information about co‐migrating components of urine extract. The main challenge consisted of developing high‐quality multivariate curve resolution with alternating least squares models of multicomponent peaks acquired during the CE analysis of nucleoside patterns in 18 urine samples. The recovered ultraviolet visible (UV–Vis) spectra have been employed to identify additional nucleosides, such as 1‐methylinosine, 2‐methylguanosine, and 1‐methylguanosine, whose presence in the metabolic profile produced by the applied CE‐DAD method has not yet been recognized. Concentration profiles of these compounds can be used in metabonomic studies.     

Kinetic analysis of reactions of Si-based epoxy resins by near-infrared spectroscopy, 13C NMR and soft-hard modelling

Soft- and hard-modelling strategy was applied to near-infrared spectroscopy data obtained from monitoring the reaction between glycidyloxydimethylphenyl silane, a silicon-based epoxy monomer, and aniline. On the basis of the pure soft-modelling approach and previous chemical knowledge, a kinetic model for the reaction was proposed. Then, multivariate curve resolution-alternating least squares optimization was carried out under a hard constraint, that compels the concentration profiles to fulfil the proposed kinetic model at each iteration of the optimization process. In this way, the concentration profiles of each species and the corresponding kinetic rate constants of the reaction, unpublished until now, were obtained. The results obtained were contrasted with ¹³C NMR. The joint interval test of slope and intercept for detecting bias was not significant (α = 5%).     

高效液相色谱法测定环氧树脂粘接剂中的双酚A

建立了进出口建筑用环氧树脂粘接剂中双酚A的高效液相色谱-荧光检测法。对提取方法和色谱条件进行了研究,结果表明采用乙醇超声提取样品15min可获得良好的提取效果。以乙腈和水为流动相,采用梯度洗脱可消除样品的基质干扰。方法对环氧树脂粘接剂中双酚A的定量限(LOQ)为0.5 mg/kg,在2～4000 ng/mL范围内,线性相关系数为0.9996。在5个添加水平下回收率在89.1%～100.8%之间。     

高效液相色谱法测定头孢他啶的含量及杂质

采用高效液相色谱法测定了头孢他啶的含量及杂质。以Alltima C18色谱柱(250 mm×4.6 mm,5 μm)为分离柱,以乙腈和磷酸盐缓冲溶液(pH 3.9)分别为流动相A和流动相B进行梯度洗脱,流速1.3 mL/min,柱温35 ℃,紫外检测波长255 nm。从头孢他啶药物中共分出14个杂质,且14个杂质间具有良好的分离度。头孢他啶在0.267~1069 μg/mL范围内与峰面积具有良好的线性关系(r=1.0000);其定量限(S/N=10)和最低检出限(S/N=3)分别为3.1 ng和0.93 ng。3个浓度的日内测定值的相对标准偏差(RSD）为0.72%(n=3),日间测定值的RSD为0.91%(n=3)。头孢他啶溶液在4 ℃避光条件下放置24 h保持稳定。本方法与欧洲/英国药典和日本药局方的方法比较,具有分离杂质数量多、分离度好的优点。     

Determination of five pesticides in juice,fruit and vegetable samples by means of liquid chromatography combined with multivariate curve resolution

The aim of this work was to quantify five commonly used pesticides (propoxur, carbaryl, carbendazim, thiabendazole and fuberidazole) in real samples as: tomato, orange juice, grapefruit juice, lemon and tangerine. The method used for the determination of these analytes in the complex matrices was high-performance liquid chromatography with diode array detection. In order to work under isocratic conditions and to complete each run in less than 10 min, the analysis was carried out applying multivariate curve resolution coupled to alternating least-squares (MCR–ALS). The flexibility of this applied multivariate model allowed the prediction of the concentrations of the five analytes in complex samples including strongly coeluting analytes, elution time shifts, band shape changes and presence of uncalibrated interferents. The obtained limits of detection (in μg L⁻¹) using the proposed methodology were 2.3 (carbendazim), 0.90 (thiabendazole), 12 (propoxur), 0.46 (fuberidazole) and 0.32 (carbaryl).     

高效液相色谱法分析十溴二苯乙烷产品

采用Zorbax C18色谱柱(5 μm,150 mm×4.6 mm)于40 ℃下分离十溴二苯乙烷产品,以甲醇-四氢呋喃(体积比为70∶30)为流动相,在230 nm波长下检测。实验结果显示,在十溴二苯乙烷的质量浓度为0.001～0.100 g/L时,其浓度与峰面积有较好的线性关系。该方法对十溴二苯乙烷的回收率大于96%,相对标准偏差为4.0%,可替代热分析法分析十溴二苯乙烷,且能满足工业生产检测的要求。     

On-line HPLC combined with multivariate statistical process control for the monitoring of reactions

On-line high performance liquid chromatography is used to monitor a steady state reaction over 35.2 h, with 197 chromatograms recorded as the reaction progresses. For each chromatogram, peaks are detected, baseline corrected, aligned and integrated to provide a peak table consisting of the intensities of 19 peaks, two corresponding to the reactants, one to the product and one to the solvent, the remaining being impurities, by-products or intermediates. D-charts and Q-charts from multivariate statistical process control are applied to the data to determine which samples are out of control and also provide diagnostic insight into why these samples are problematic. The D-chart is best at looking at overall performance issues such as problems with mixing or difficulties with instrument operation, whereas the Q-charts are best at detecting impurities during the reaction.     

高效液相色谱法手性分离联萘二酚苯甲酸酯对映体

采用Chirex(S)-LEU(S)-NEA、ChiralcelOD-H和ChiralpakAD-H手性色谱柱直接拆分了2′-羟基-1,1′-联萘-2-苯甲酸酯(HBNB)、1,1′-联萘-2,2′-二苯甲酸酯(BNDB)和2′-甲氧基-1,1′-联萘-2-苯甲酸酯(MBNB)对映体。分别考察了流动相组成、柱温和化合物结构对手性分离的影响。结果表明:3对联萘二酚苯甲酸酯对映体在ChiralpakAD-H柱上的拆分效果最好。当采用正己烷/异丙醇(40/60,v/v)为流动相时,HBNB、BNDB和MBNB对映体的分离因子(α)和分离度(Rs)分别为1.76、1.74、1.40和6.47、7.81、4.75。对比联萘二酚(BN)的分离,从联萘分子中2-位取代基、对映体出峰顺序和热力学参数等方面探讨了相关手性分离机理。     

Handling time misalignment and rank deficiency in liquid chromatography by multivariate curve resolution: Quantitation of five biogenic amines in fish

Biogenic amines (BAs) are used for identifying spoilage in food. The most common are tryptamine (TRY), 2-phenylethylamine (PHE), putrescine (PUT), cadaverine (CAD) and histamine (HIS). Due to lack of chromophores, chemical derivatization with dansyl was employed to analyze these BAs using high performance liquid chromatography with a diode array detector (HPLC-DAD). However, the derivatization reaction occurs with any primary or secondary amine, leading to co-elution of analytes and interferents with identical spectral profiles, and thus causing rank deficiency. When the spectral profile is the same and peak misalignment is present on the chromatographic runs, it is not possible to handle the data only with Multivariate Curve Resolution and Alternative Least Square (MCR-ALS), by augmenting the time, or the spectral mode. A way to circumvent this drawback is to receive information from another detector that leads to a selective profile for the analyte. To overcome both problems, (tri-linearity break in time, and spectral mode), this paper proposes a new analytical methodology for fast quantitation of these BAs in fish with HPLC-DAD by using the icoshift algorithm for temporal misalignment correction before MCR-ALS spectral mode augmented treatment. Limits of detection, relative errors of prediction (REP) and average recoveries, ranging from 0.14 to 0.50 µg mL⁻¹, 3.5–8.8% and 88.08%–99.68%, respectively. These are outstanding results obtained, reaching quantification limits for the five BAs much lower than those established by the Food and Agriculture Organization of the United Nations and World Health Organization (FAO/WHO), and the European Food Safety Authority (EFSA), all without any pre-concentration steps. The concentrations of BAs in fish samples ranged from 7.82 to 29.41 µg g⁻¹, 8.68–25.95 µg g⁻¹, 4.76–28.54 µg g⁻¹, 5.18–39.95 µg g⁻¹ and 1.45–52.62 µg g⁻¹ for TRY, PHE, PUT, CAD, and HIS, respectively. In addition, the proposed method spends less than 4 min in an isocratic run, consuming less solvent in accordance with the principles of green analytical chemistry.     

高效液相色谱手性流动相法拆分酮基布洛芬对映体

以Lichrospher C18为分析柱, 将β-环糊精、2,6-二甲基-β-环糊精、2,3,6-三甲基-β-环糊精分别作为手性流动相添加剂, 系统地研究了R,S-酮基布络芬对映体在HPLC系统中的拆分. 建立了以2,3,6-三甲基-β-环糊精为手性流动相添加剂分离R,S-酮基布络芬对映体方法.     

高效液相色谱法同时测定化妆品中的呋喃妥因和呋喃唑酮

建立了一种同时检测化妆品中呋喃妥因和呋喃唑酮的高效液相色谱法(HPLC)。乳液、膏霜、化妆水、散粉、唇膏类等不同类型的化妆品样品由乙腈-甲醇(体积比为1∶1)混合溶液超声提取后进行HPLC分析。采用Kromasil C18色谱柱,以乙腈-0.4%乙酸溶液(体积比为30∶70)为流动相,流速1.0 mL/min,采用二极管阵列检测器检测,检测波长为365 nm;采用外标法定量,呋喃妥因和呋喃唑酮检测的线性范围为0.1～20 mg/L,相关系数为0.9999,最低检出限为1.2 mg/kg;在0.2,1.0,10.0 mg/L加标水平下,平均回收率为88.0%～104.6%,相对标准偏差为0.5%～4.8%。该方法快速准确,可用于化妆品中呋喃妥因和呋喃唑酮的同时测定。     

Factors that affect quantification of diode array data in comprehensive two-dimensional liquid chromatography using chemometric data analysis

There has been a tremendous increase in research on comprehensive two dimensional LC (LC×LC); however, to date, the central analytical issue, quantification, has received only minimal attention. It is vital to the further development of LC×LC that a greater understanding of the specific factors affecting peak quantification in LC×LC be attained. This work focuses on the following factors: data complexity, retention time shifting, dynamic range issues, chromatographic and spectral peak overlap and difficulties related to background signal removal. The above mentioned factors that affect peak quantification are investigated using fourteen replicate analyses of a urine sample, representing the effects of such factors when analyzing samples in complex matrices. We demonstrate that quantification of LC×LC data is improved following implementation of chemometric techniques that minimized the deleterious effects on quantification due to chromatographically overlapped peaks, retention time shifting and background signal interference. The chemometrically resolved data shows a 2.5-fold increase in precision of quantification over the quantification of the raw data. It is also demonstrated that the method quantifies sixteen peaks that were not visually evident prior to chemometric analysis. The purpose of this paper is to determine the impact of these issues on the effectiveness of LC×LC as a technique for the quantitative analysis of complex samples.     

高效液相色谱法同时测定厚朴温中胶囊中的7种有效成分

建立了同时测定厚朴温中胶囊中山姜素、甘草酸、和厚朴酚、小豆蔻明、木香烃内酯、去氢木香内酯及厚朴酚含量的反相高效液相色谱法。固定相为Scienhome C18柱(250 mm×4.6 mm,5 μm),流动相为甲醇-乙腈-0.06%磷酸溶液(体积比为38∶27∶35),流速为1.0 mL/min,柱温为30 ℃,检测波长为235 nm。在上述条件下,山姜素、甘草酸、和厚朴酚、小豆蔻明、木香烃内酯、去氢木香内酯及厚朴酚的质量浓度分别在0.885～17.7,107～2140,8.85～17.7,1.035～20.7,4.85～97,5.9～118和17.5～350 mg/L时与色谱峰面积之间的线性关系良好;回收率分别为96.9%～101.1%,96.0%～100.5%,100.3%～100.8%,97.7%～101.4%,100.4%～102.3%,96.0%～102.3%和96.2%～100.6%。该方法简便、快速、准确,可用于厚朴温中胶囊的质量控制。     

Ionic liquids extraction of Para Red and Sudan dyes from chilli powder, chilli oil and food additive combined with high performance liquid chromatography

A simple analytical method, based on the coupling of ionic liquid-based extraction with high performance liquid chromatography (HPLC), is developed for the determination of Sudan dyes (I, II, III and IV) and Para Red in chilli powder, chilli oil and food additive samples. Two ionic liquids (ILs), 1-butyl-3-methylimidazolium hexafluorophosphate ([C₄mim][PF₆]) and 1-octyl-3-methylimidazolium hexafluorophosphate ([C₈mim][PF₆]), were compared as extraction solvents; experiments indicated that the latter possesses higher recoveries for each analyte. Parameters related to extraction of Sudan dyes and Para Red were also optimized. Under the optimal conditions, good reproducibility of extraction performance was obtained, with the relative standard deviation (RSD) values ranging from 2.0% to 3.5%. The detection limits of Sudan dyes and Para Red (LOD, S/N = 3) were in the range of 7.0-8.2 μg kg⁻¹ for chilli powder and 11.2-13.2 μg L⁻¹ for chilli oil and food additive. The recoveries were in the range of 76.8-109.5% for chilli powder samples and 70.7-107.8% for chilli oil and food additive samples.     

高效液相色谱法同时测定发酵液中赤藓糖醇和L-赤藓酮糖的含量

建立了采用高效液相色谱(HPLC)同时测定发酵液中底物赤藓糖醇和产物L-赤藓酮糖含量的方法。采用Lichrospher 5-NH2色谱柱(250 mm×4.6 mm),柱温30 ℃,以乙腈-水(体积比为9:1)为流动相,流速1.0 mL/min。用示差折光检测器检测赤藓糖醇,检测器温度为35 ℃。用紫外检测器在室温下检测L-赤藓酮糖,检测波长为277 nm。所得赤藓糖醇的线性范围为1.00～100.00 g/L,相关系数为0.9985,检出限为0.10 g/L,定量限为0.45 g/L;所得L-赤藓酮糖的线性范围为1.00～100.00 g/L,相关系数为0.9958,检出限为0.50 g/L,定量限为0.87 g/L;赤藓糖醇的日内和日间相对标准偏差(RSD)分别小于3.28%和5.30%, L-赤藓酮糖的日内和日间RSD分别小于2.16%和2.25%;回收率均大于99%。取不同时间的发酵液样品分别用上述方法测定,结果表明所建立的HPLC法不受发酵液中其他组分的影响,可同时测定底物赤藓糖醇和产物L-赤藓酮糖的含量。     

高效液相色谱分析化妆品中的防腐剂氯苯甘醚

建立了化妆品中防腐剂氯苯甘醚的高效液相色谱检测方法。采用C₁₈色谱柱(250 mm×4.6 mm,5 μm)和二极管阵列检测器,以1.0 mL/min甲醇-水(55：45,v/v)为流动相,检测波长为280 nm,柱温为25 ℃。方法的检出限(以3倍信噪比计)可达到3 ng;在1~500 mg/L范围内,峰面积与质量浓度呈良好的线性关系,相关系数为1.0000。高、中、低不同水平的加标回收率为99.0%~103%,相对标准偏差≤1.2%。同时进行了干扰试验和实际样品的测定,并组织3家实验室进行了方法验证。该方法操作简便,准确度、灵敏度和稳定性高,可用于化妆品中防腐剂氯苯甘醚的检测。     

高效液相色谱法同时测定血浆中的10种蛋白同化激素

建立了一种用于10种蛋白同化激素的同时分离检测的高效液相色谱法。根据被分析物的性质,以C18反相色谱柱为分离柱,以乙腈和水为流动相,采用梯度洗脱方式,并在194～290 nm的范围内快速调节检测波长,使各物质均在最大吸收波长处被检出。在优化的条件下,10种被测组分在10 min内实现了快速的基线分离,检出限在0.01～0.10 μg/mL范围内。在兔血浆中进行加标回收率测定,10种被测组分的加标回收率为70.3%～120%。选取美雄醇为代表进行实际动物实验,成功检测到耳脉注射美雄醇后兔血浆内的美雄醇成分。实验结果表明该方法可行,快速简便,准确可靠。     

高效液相色谱法测定食品接触材料中苯酚和4-叔丁基苯酚迁移量

提出了食品接触材料在水、3％(质量分数)乙酸溶液、乙醇(1+9)溶液、异辛烷4种食品模拟物中苯酚、4-叔丁基苯酚迁移量的高效液相色谱测定方法.不同种类的食品模拟物采用不同的样品前处理方法提取后,用Diamonsil C18色谱柱为固定相,甲醇-水为流动相梯度洗脱,以激发波长220 nm、发射波长312nm的荧光检测器进...     

High performance liquid chromatography - Quantitative nuclear magnetic resonance - High performance liquid chromatography for purity measurement of human insulin

Quantitative Nuclear Magnetic Resonance (qNMR) is a reliable quantitative spectroscopic technique, wherein the intensity of a resonance line is directly proportional to the number of resonant nucleus, and the absolute content of the compound can be determined, this means the inorganic stabilizer in the sample would not affect the result of qNMR. High performance liquid chromatography (HPLC) is a common analytical method with a high separation capacity. This study combined HPLC and qNMR, to measure the purity of Human Insulin (HI). It started from an original HI. The first step is purifying the original HI by HPLC to get a purified HI, with organic purity of 99.78%. The second step is assessing the absolute content of the purified HI by qNMR, and got 40.25%. The third step is measuring the purity of original HI by HPLC again, using the purified HI as the reference material. This method, called HPLC-qNMR-HPLC, is more accurate (84.12%?±?1.14%) than the traditional IDMS (isotope dilution mass spectrometry) method (86.6%?±?3.4%). This study expanded the application of qNMR to proteins with molecular weight of about 5800, and showed that this method can be widely used in measuring the purity of macromolecular proteins.