高效阴离子交换色谱-脉冲安培法检测小鼠尿液中的甘露醇、单糖和乳果糖

采用高效阴离子交换色谱-脉冲安培检测法(HPAEC-PAD)建立了小鼠尿液中甘露醇、单糖(包括半乳糖、葡萄糖、甘露糖和果糖)和乳果糖的分析方法。样品经离心沉淀除去蛋白并过分子膜,以CarboPacTM PA1阴离子交换柱为分离柱,采用NaOH梯度淋洗,脉冲安培四电位检测。结果表明,甘露醇、半乳糖、葡萄糖、甘露糖、果糖和乳果糖在0.1～5.0 mg/L内线性良好,线性相关系数r2为0.988～0.999,样品加标回收率为95.5%～104.2%,检出限为0.0013～0.0048 mg/L。此法准确、快速、简便,能同时对6种糖类化合物进行分析,可以跟踪检测整个糖类代谢过程中甘露醇、单糖和乳果糖之间的代谢关系。     

离子色谱-柱切换技术同步测定饮料中的三氯蔗糖、葡萄糖、果糖和蔗糖

建立了一种离子色谱-柱切换-安培检测技术同步测定饮料中三氯蔗糖、葡萄糖、果糖和蔗糖的方法。以CarboPac PA10阴离子交换保护柱和分析柱进行分离,用水和250 mmol/L NaOH梯度淋洗,脉冲安培检测。弱保留糖类在25 mmol/L NaOH流动相淋洗下分离检测,通过柱切换将保护柱切换至分析柱后,同时切换至250 mmol/L NaOH淋洗,三氯蔗糖仅通过较短的保护柱分离,4种糖类能够得到同步检测。4种糖类在0.01~20 mg/L范围内有良好的线性关系和较低的检出限,重复性好,样品测定的回收率分别为90.38%~102.88%（三氯蔗糖）、95.56%~102.75%（葡萄糖）、101.66%~114.33%（果糖）和105.03%~106.49%（蔗糖）。该方法可广泛应用于食品中强保留物质的测定。     

Simultaneous determination of 13 carbohydrates using high‐performance anion‐exchange chromatography coupled with pulsed amperometric detection and mass spectrometry

A simple, accurate, and highly sensitive method was developed for the determination of 13 carbohydrates in polysaccharide of Spirulina platensis based on high‐performance anion‐exchange chromatography coupled with pulsed amperometric detection and mass spectrometry. Samples were extracted with deionized water using ultrasonic‐assisted extraction, and the ultrasound‐assisted extraction conditions were optimized by Box–Behnken design. Then the extracted polysaccharide was hydrolyzed by adding 1 mol/L trifluoroacetic acid before determination by high‐performance anion‐exchange chromatography coupled with pulsed amperometric detection and confirmed by high‐performance anion‐exchange chromatography coupled with mass spectrometry. The high‐performance anion‐exchange chromatography coupled with pulsed amperometric detection method was performed on a CarboPac PA20 column by gradient elution using deionized water, 0.1 mol/L sodium hydroxide solution, and 0.4 mol/L sodium acetate solution. Excellent linearity was observed in the range of 0.05–10 mg/L. The average recoveries ranged from 80.7 to 121.7%. The limits of detection and limits of quantification for 13 carbohydrates were 0.02–0.10 and 0.2–1.2  μg/kg, respectively. The developed method has been successfully applied to ambient samples, and the results indicated that high‐performance anion‐exchange chromatography coupled with pulsed amperometric detection and mass spectrometry could provide a rapid and accurate method for the simultaneous determination of carbohydrates.     

Ion Chromatographic Analysis of Monosaccharides and Disaccharides in Raw Sugar

A simple and effective method using ion chromatography was developed for the simultaneous determination of five monosaccharides (arabinose, glucose, fructose, xylose, and ribose) and two disaccharides (sucrose and lactose) in raw sugar samples. The separation was performed on a CarboPac PA 10 column using the gradient elution of sodium hydroxide and water as the mobile phase. Monosaccharides and disaccharides were detected by an integrated pulsed amperometric detection (IPAD) using gold working electrode. Acid hydrolysis was used for sample preparation before the analysis of glucose and fructose. All the studied sugars showed good linear ranges within 0.5–100 µg mL⁻¹ with the correlation coefficients higher than 0.997. The limits of detection were all less than 0.5 µg mL⁻¹. The RSDs of the method were less than 10 %. The recoveries of the sugars that spiked in raw sugar samples ranged from 96.1 to 102.4 %. The method was successfully applied for the analysis of sugars in raw sugar samples. Sucrose is the major constituent found in the samples at 97 %.

     

高效阴离子交换-脉冲安培法测定化妆品中葡萄糖酸锌含量

建立了高效阴离子交换-脉冲安培法测定化妆品中葡萄糖酸锌的含量.样品用水超声提取后,离心取上清液过On Guard Ⅱ RP柱除去疏水性化合物,再经CarboPac PA1和CarboPacPA20保护柱分离,脉冲安培检测,葡萄糖酸锌在0.1～5.0mg/L范围内线性关系良好(r2=0.9999),加标回收率在98.9～107.7％之间,方法检出限为0.042mg/L,对应样品中检出限为4.2mg/kg,方法简单,灵敏度高.     

高效阴离子交换色谱-脉冲安培检测法测定烤烟中的水溶性葡萄糖、果糖和蔗糖

用高效阴离子交换色谱-脉冲安培检测法（HPAEC-PAD）测定了烤烟中的水溶性葡萄糖、果糖和蔗糖。采用水浸取及膜过滤法处理烤烟样品,以Dionex CarboPac PA-1阴离子交换柱为色谱柱,0.2 mol/L NaOH水溶液为淋洗液进行分离测定。葡萄糖、果糖和蔗糖的含量与其峰面积的线性关系良好,回收率均在97%以上。方法简便易行,灵敏度高,重现性良好,可以实现对烟草中单糖的快速分离和测定。     

离子色谱-脉冲安培法测定芦荟多糖中7种单糖的含量

采用水提醇沉法提取芦荟鲜叶中的多糖，经三氟乙酸水解，利用Dionex CarboPac PA10高效阴离子色谱柱分离，氢氧化钠梯度淋洗，积分脉冲安培检测，建立了芦荟多糖中岩藻糖、鼠李糖、阿拉伯糖、半乳糖、葡萄糖、甘露糖和木糖7种常见单糖的测定方法。结果表明：7种单糖在线性范围内的相关系数（R²）均高于0.997，检出限为0.007~0.024 mg/L，加标回收率为97.5%~102.5%，相对标准偏差（RSD）为0.1%~4.8%。该法简单、快速、灵敏、准确，可用于芦荟多糖中单糖含量的测定和多糖组成的研究。     

离子色谱法测定大肠癌患者尿液中的甘露醇和乳果糖

建立了大肠癌患者尿液中甘露醇和乳果糖的高效阴离子交换分离-脉冲积分安培(HPAEC-PAD)检测方法.样品经稀释、净化、过滤后进行色谱分析,采用Carbopac PA1(250 mm×4mm)阴离子交换柱分离,以NaOH-乙酸钠梯度淋洗液为流动相,流速1.0 mL/min,脉冲积分安培检测器(PAD)检测,外标法定量.结果表明,甘露醇和乳果糖的的线性范围为0.2～20 mg/L,相关系数分别为0.9995和0.9998,回收率为91.7％～102.6％,相对标准偏差均小于2.1％,检出限为0.05和0.06 mg/L(S/N=3).本方法前处理简便、灵敏度高、重现性好,可用于大肠癌患者尿液中的甘露醇和乳果糖的测定.     

Separation and determination of alditols and sugars by high-pH anion-exchange chromatography with pulsed amperometric detection

Carbohydrates such as alditols (polyols or sugar alcohols), monosaccharides and disaccharides are separated as anions by anion-exchange chromatography with a sodium hydroxide eluent, MA1 CarboPac column and pulsed amperometric detection. We report a high-pH anion-exchange chromatographic-pulsed amperometric detection (HPAEC-PAD) method that determines all the polyols used as food additives in food products and the most commonly found mono- and disaccharides on a routine basis. The linearity, repeatability, internal reproducibility and accuracy are described. The applicability of the method has been demonstrated by the analysis of 46 relevant samples and by participation twice in the Food Analysis Performance Assessment Scheme (FAPAS) testing programme for food additives.     

Ion chromatographic methods for the detection of starch hydrolysis products in ruminal digesta.

Dionex high-performance ion chromatographic methods were evaluated for separation and quantitation of plant sugars and starch digestion products in the ruminal digesta of cattle. Mono- and disaccharides were eluted from a Dionex CarboPac PA1 column with sodium hydroxide used isocratically or as a pH gradient. Maltooligosaccharides which had a degree of polymerization (DP) less than 30 glucose residues were eluted in 60 min by a sodium hydroxide eluent containing a sodium acetate gradient. Carbohydrates were detected amperometrically. Responses were linear (r2 greater than 0.99) for glucose, disaccharides and maltooligosaccharides (DP less than 8). Precipitation and solid-phase extraction methods were evaluated for clean-up of samples of feedstuffs, ruminal contents, and bacterial culture fluids. Perchloric acid precipitation hydrolyzed sucrose but did not affect recoveries of cellobiose, isomaltose or maltose. Ethanol in concentrations of 79 and 86% precipitated maltooligosaccharides having chain lengths larger than 14 and 9 glucose residues, respectively. Maltooligosaccharide recoveries from solid-phase extraction columns varied with maltooligosaccharide size and column packing. Recoveries were greater than 94% for short chains (DP less than 6) eluted from phenyl-substituted columns and variable for all oligosaccharides eluted from C18 columns. Applications of these methods are presented and include: (1) detection of sugars in ruminant feed, (2) monitoring changes in ruminal sugars after feeding and (3) monitoring changes in extracellular sugars and oligosaccharides in the culture fluids of the ruminal bacterium, Bacteroides ruminicola.     

Application of Copper Electrode Based Amperometric Detector Cell for LC Analysis of Main Sugar Component of Honey and Nectar

A method for quantification of the main sugar components of honey and nectars are worked out and investigated. The method employs IC separation on CarboPac PA1 column with sodium hydroxide eluent and home made, electrochemical detector cells that contain copper working electrode. The detector cells operate in amperometric mode. The electrochemical oxidation of the sugar components was studied, estimating the number of electrons exchanged, the rate constant of the electrode reaction. The electrode processes showed electrocatalytic character with formate ions as main product of oxidation. Real samples of honey and nectar taken from different plants were analyzed with the method proposed.     

高效阴离子交换色谱-脉冲安培检测法测定乳粉中的低聚果糖

建立了测定乳粉中低聚果糖的高效阴离子交换色谱-脉冲安培检测(HPAEC-PAD)方法。样品经50%(v/v)乙醇水溶液提取,On Guard RP柱除脂,CarboPac PA200阴离子交换色谱柱(250 mm×3 mm)分离。采用水、0.2 mol/L NaOH溶液和0.4 mol/L NaAc溶液三元梯度淋洗,流速为0.4 mL/min,柱温为30 ℃,进样量为25 μL,脉冲安培检测器检测。蔗果三糖、四糖、五糖在0.05~10 mg/L范围内线性关系良好,相关系数(r²)> 0.9993;定量限分别为0.02、0.005和0.02 mg/L。在0.5、1.0、5.0 mg/L添加水平下,蔗果三糖、四糖、五糖的平均回收率为86.0%~114.0%。该方法处理简单、结果准确、灵敏度高,适用于乳粉中低聚果糖的测定。     

二维离子色谱法同时测定4种无机阴离子和葡萄糖酸根离子

建立了一种新的二维离子色谱分析模式,应用阀切换技术并联抑制电导和脉冲安培双检测体系,同时测定Cl^-、NO₂^-、SO₄^2-、NO₃^-和葡萄糖酸根离子。第一维色谱采用Ionpac AG18+Ionpac AS18阴离子分析柱,分别以5和20 mmol/L的NaOH溶液等度淋洗,流速为1.0 mL/min,进样量为25 μL,抑制电导检测Cl^-、NO₂^-、SO₄^2-和NO₃^-。第二维色谱采用CarboPac PA1+CarboPac PA20两保护柱串联,以90 mmol/L NaOH溶液、0.8 mL/min的流速洗脱,由AG15柱分离富集葡萄糖酸根,脉冲安培检测器检测。结果表明:无机阴离子在0.1~5.0 mg/L、葡萄糖酸根在0.0856~4.2825 mg/L范围内有良好的线性关系,RSD在1.05%~1.94%之间,相关系数(R²)在0.9945以上;无机阴离子的方法检出限为0.615~2.17 μg/L,葡萄糖酸根的方法检出限为24.24 μg/L;回收率在90.3%~102.8%之间。该方法并联两种检测模式,有良好的准确度和精密度,适用于复杂样品的分离分析。     

Chromatographic methods for product-profile analysis and isolation of oligosaccharides produced by heparinase-catalyzed depolymerization of heparin.

A two-dimensional chromatography method for monitoring the formation of oligosaccharides produced by heparinase-catalyzed depolymerization of heparin is reported. In the first step of the two-dimensional method, the depolymerized heparin is size-fractionated by high-performance gel permeation chromatography (HPGPC). The size-uniform fractions are then separated on the basis of charge by strong anion-exchange (SAX) HPLC on a high resolution CarboPac PA1 column. To demonstrate application of the two-dimensional product-profile analysis method, data are presented for the heparinase I-catalyzed depolymerization of heparin in the absence and presence of histamine, a ligand that binds site-specifically to heparin. Results from the two-dimensional analysis indicate that histamine alters the extent of depolymerization and the product-profiles for the tetrasaccharide and hexasaccharide fractions. The use of CarboPac PA1 columns for the semi-preparative scale separation of oligosaccharides in size-uniform fractions isolated from depolymerized heparin by low-pressure (gravity flow) GPC is also reported. The semi-preparative scale CarboPac PA1 column gives high resolution and excellent reproducibility after repeated use over an extended period of time, making it possible to reliably combine fractions from multiple separations. The oligosaccharides are eluted from the CarboPac PA1 column with a NaCl gradient at relatively low pH (3 or 7) where they are stable. An efficient two-step procedure is described for desalting oligosaccharides separated     

Direct determination of free methionine in soy-based infant formula

A method was developed for the direct determination of free methionine in soy-based infant formula, with analyte separation and quantitation by reversed-phase liquid chromatography (LC), and UV absorbance at 214 nm, respectively. Sample preparation required only dilution with mobile phase and syringe filtration. Using a 0.02M KH2PO4 mobile phase (pH adjusted to 2.9 with 85% o-phosphoric acid) and 0.7 mL/min flow rate, methionine eluted at approximately 8 min, and total run time was 14 min after column regeneration with acetonitrile-water. System linearity was demonstrated as peak area versus analyte concentration, ranging from 80 to 120% of the formula specification for free methionine (r > 0.999, and all residuals < 0.45%). Intermediate precision relative standard deviation values were < 1.5% for ready-to-feed and reconstituted powder samples, and recoveries ranged from 98.0 to 103.5% for inter-method comparison with an amino acid analyzer method. The limit of quantitation was 3 mg methionine/L in the "as fed" infant formula. Despite the relatively weak UV absorptivity of methionine, the 214 nm signal was sufficiently intense in the 30-65 mg/L (201-436 microM) range to afford quantitation by peak area proportionation versus a 2-point external standard calibration. This direct UV detection after reversed-phase LC separation provides a simple and accurate method for determining free methionine without derivatization.     

Isolation and quantitation of carbohydrates in sheep plasma by high-performance liquid chromatography

The application of ultraviolet detection at 190 nm following chromatography on a Ca2+ cation-exchange column with a mobile phase of water enables the low amounts of carbohydrates present in plasma to be quantitated. The separation and quantitation of carbohydrates in maternal and fetal sheep plasma and amniotic fluid are described, as is the application of this method to the determination of specific radioactivities of glucose and fructose in plasma.     

离子对色谱法测定化妆品中的苯酚磺酸锌

建立了离子对色谱测定不同基质化妆品中苯酚磺酸锌的分析方法。水剂类和香波类化妆品用20%乙腈水溶液提取,膏霜类和散粉类用80%乙腈水溶液提取,唇膏类加四氢呋喃并用80%乙腈水溶液提取,提取液离心、过滤处理。以四丁基氢氧化铵为离子对试剂,考察了苯酚磺酸锌在离子对色谱中的保留行为并优化了最佳色谱条件:以Kromasil C18(4.6 mm×250 mm,5μm)色谱柱分离,流动相为5 mmol/L四丁基氢氧化铵+25 mmol/L磷酸二氢钠缓冲溶液(pH 2.5)-乙腈(80∶20),等度洗脱,流速1.0 mL/min,柱温30℃,检测波长230 nm。该方法对苯酚磺酸锌的定量下限为:水剂和香波基质中为24 mg/kg、膏霜和唇膏基质中为120 mg/kg、散粉基质中为60 mg/kg,在0.5～50 mg/L范围内,苯酚磺酸锌的线性关系良好,相关系数为0.999 8。在低、中、高3个加标水平下,苯酚磺酸锌的平均回收率为94%～99%,相对标准偏差为0.57%～3.9%。该方法快速、简便、准确,可用于化妆品中苯酚磺酸锌的测定。     

Simultaneous determination of rocuronium and its eight impurities in pharmaceutical preparation using high-performance liquid chromatography with amperometric detection

A sensitive and selective HPLC method with amperometric detection (HPLC-ED) for the determination of rocuronium bromide and its eight impurities has been developed. The analysis was performed on Hypersil 100 Silica column 5 microm (250 mm x 4.6 mm; Thermo Electron). The mobile phase consisting of 4.53 g l(-1) solution of tetramethylammonium hydroxide adjusted to pH 7.4 with 85% phosphoric acid:acetonitrile (1:9), was found the best for the separation and determination of the studied compounds. The chromatograms were recorded over 10 min using the amperometric detection at a potential +0.9 V of the glassy carbon electrode versus the reference electrode Ag/AgCl. The limit of quantitation was 45 ng ml(-1) for rocuronium and from 25 to 750 ng ml(-1) for the examined impurities. The proposed HPLC-ED method was successfully applied to the analysis of rocuronium and its impurities in Esmeron solution for injection.     

HPAE-PAD – a sensitive method for the determination of carbohydrates

High performance anion exchange chromatography with pulsed amperometric detection (HPAE-PAD) was used for the determination of eleven monosaccharides. Three analytical columns with different selectivities were tested, and the resulting separations were compared calculating precision and detection limits. The monosaccharides could be separated on CarboPAC PA10 in one analysis run with the lowest detection limits and a high precision. For the determination of polysaccharides and humic bound carbohydrates in natural organic matter, an hydrolysis step had to be carried out. With the exception of fructose, the recoveries varied between 56% and 83%. The described methods were applied for the determination of bound carbohydrates in a bog lake water and a soil extract without preconcentrating the samples.     

高效阴离子交换色谱-铜/铂修饰电极安培法测定大观霉素

采用阴离子交换色谱分离,在CuSO4溶液中加入少量镧系化合物,经电沉积制备La3+-Cu/pt/CME工作电极,建立了直流安培电化学法(DC)直接检测硫酸大观霉素的方法。考察了流动相浓度、测定电位等参数对色谱分离和测定的影响。在固定相为CarboPac PA10阴离子交换柱、流动相为26mmol/L NaOH,流速为0.6mL/min的色谱条件下,检测电位为0.68V时,硫酸大观霉素峰面积与其浓度在0.12～12mg/L(r=0.9991)和12～280mg/L(r=0.9995)两个范围内呈线性。本方法不需要柱前和柱后衍生化,能同时测定硫酸大观霉素中的主要组分和杂质。修饰电极制作方法简单,催化稳定性好,可作为电化学传感器测定硫酸大观霉素中的各组分。