高效液相色谱-蒸发光散射法测定葡萄果实的糖分

建立了测定葡萄果实中果糖、葡萄糖、蔗糖含量的高效液相色谱-蒸发光散射检测法(HPLC-ELSD)。采用Prevail carbohydrate ES色谱柱(250×4.6mm,5μm),流动相为乙腈-水(体积比78∶22),流速1mL/min。选择漂移管温度50℃,N2流速1.5L/min。该条件下,果糖、葡萄糖、蔗糖含量在1.0~50.0μg与其峰面积具有良好的线性关系,相关系数均在0.9996以上;果糖、葡萄糖、蔗糖的平均回收率分别为98.17%、98.47%、99.82%,精密度分别为0.71%、0.92%、0.96%,稳定性分别为1.5%、2.7%、1.8%。方法快速、简单、准确,可用于测定葡萄果实的果糖、葡萄糖、蔗糖。     

超高效液相色谱-串联质谱法测定卷烟中果糖、葡萄糖、蔗糖、麦芽糖

建立超高效液相色谱–串联质谱法测定卷烟中果糖、葡萄糖、蔗糖、麦芽糖4种水溶性糖的含量。样品用水超声提取,稀释过滤后直接进样,以Acquity BEH Amide色谱柱为分析柱,乙腈和水为流动相,梯度洗脱,采用负离子多反应监测模式分析。果糖和葡萄糖的线性范围为2.5～30μg/mL,蔗糖和麦芽糖的线性范围为0.25～3μg/mL,线性相关系数均大于0.997,方法检出限均为0.03 mg/g。加标样品的平均回收率为93.6%～101.0%,测定结果的相对标准偏差为0.7%～2.9%(n=6)。该方法简便、快速,可用于卷烟样品中果糖、葡萄糖、蔗糖、麦芽糖的测定。     

液相色谱-质谱联用技术测定无糖食品中果糖、葡萄糖、蔗糖、麦芽糖和乳糖

建立了无糖食品中葡萄糖、果糖、蔗糖、麦芽糖、乳糖的高效液相色谱-串联四极杆质谱联用测定方法.本方法以水提取样品,以Waters Carbohydrate Analysis柱(300 mm×3.9 mm, 10 μm)分离,流动相为水-乙腈(15∶ 85, V/V),电喷雾负离子MRM模式检测.方法的检出限为0.1 g/kg;线性范围为2.5～125.0 mg/L;加标回收率为86.2%～97.7%;相对标准偏差为3.1%～8.7%.     

高效液相色谱法测定浓缩果汁中5种可溶性糖

建立同时测定浓缩果汁中木糖、果糖、葡萄糖、蔗糖和麦芽糖的高效液相色谱–蒸发光散射检测方法(HPLC–ELSD)。样品采用乙腈–水(50∶50)稀释,用酰胺键合色谱柱BEH Amide分离,蒸发光散射检测器检测,在10 min内完成木糖、果糖、葡萄糖、蔗糖、麦芽糖的分离。浓缩果汁中5种可溶性糖的质量浓度在0.1～2.0 mg/m L与色谱峰面积均呈线性关系,相关系数为0.991 0～0.993 1,检出限为0.23%～0.98%,样品加标回收率为88.6%～104.3%,测定结果的相对标准偏差为2.2%～6.3%(n=6)。该方法快速、准确,可作为浓缩果汁中糖含量的质量控制方法。     

UPC~2-MS法快速检测蜂蜜中的果糖、葡萄糖、蔗糖和麦芽糖

建立了蜂蜜中果糖、葡萄糖、蔗糖和麦芽糖的超高效合相色谱-质谱(UPC2-MS)快速检测的方法。样品先用少量的水溶解,再用正己烷/异丙醇(1:1,V/V)溶解,经ACQUITY UPC2BEH(100 mm×3.0 mm,1.7μm)色谱柱分离,以超临界CO2-甲醇(含0.1%NH3·H2O,V/V)为流动相进行梯度洗脱,流速为1.8 m L/min,通过质谱检测器在负离子电喷雾模式下对目标化合物进行分析,外标法定量。检测结果表明:果糖、葡萄糖、蔗糖和麦芽糖在2~150 mg/L范围线性关系良好,R20.9990,定量限(LOQ,S/N≥10)为0.22~0.42 mg/L,高、中、低3个浓度水平的加标平均回收率在90.0%~107.5%范围,相对标准偏差(RSD,n=6)均小于4.0%。该方法简单快速,分离效果好,为蜂蜜中果糖、葡萄糖、蔗糖和麦芽糖的分离测定提供了新的色谱技术平台。     

高效液相色谱法同时测定苹果中3种糖及主成分分析和聚类分析

建立高效液相色谱法同时测定苹果中D-果糖、D-葡萄糖和蔗糖含量的方法,并对不同产地样品中3种糖进行主成分分析和聚类分析,为苹果质量评价与分类提供依据。用单因素实验对苹果样品前处理条件进行优化,确定了最佳样品前处理条件:离心转速为16 000 r/min,离心时间为17 min,料液比为1∶12。D-果糖、D-葡萄糖和蔗糖的线性范围分别为0.245～1.495 mg/mL(r=0.999 1),0.104～1.004 mg/mL(r=0.999 6),0.075～1.025 mg/m L(r=0.998 2)。果糖、葡萄糖、蔗糖的加标回收率分别为96.83%～100.08%,83.51%～96.40%,93.97%～98.89%,测定结果的相对标准偏差为0.69%～1.17%(n=6)。通过聚类分析将6个产地的苹果样品分成了3类,与主成分分析结果相同。该方法简便、准确,可用于测定苹果果实中糖的类型及其含量,为苹果品质鉴定提供科学依据。     

HPLC-ELSD在1-脱氧野尻霉素,葡萄糖和葡萄糖胺的杂质分析中的应用

建立了一种高效液相分析方法可用于1-脱氧野尻霉素,葡萄糖和葡萄糖胺的杂质分析.该方法以乙腈/水酸性系统为流动相体系,色谱柱采用WatersAtlantis HILIC Silica(5 μm,150×4.6 mm),以蒸发光散射检测器(ELSD)进行检测,采用主成分自身对照法用于杂质含量的计算.方法验证结果表明,1-脱氧野尻霉素,葡萄糖和葡萄糖胺在0.008～0.04 mg/mL范围内峰面积对质量浓度呈现良好的线性,线性回归系数分别为0.9993,0.9998,0.9996.1-脱氧野尻霉素,葡萄糖和葡萄糖胺的最低检测浓度分别为0.0045,0.0040,0.0039 mg/mL.3种化合物在0.02,0.04,0.08 mg/mL 3种质量浓度点的重现性良好,RSD%均小于10%.     

高效液相色谱法测定橘红丸及蜂蜜中糖的含量

采用高效液相色谱法测定橘红丸及蜂蜜中果糖、葡萄糖、蔗糖、麦芽糖的含量,用prevail carbohydrate ES色谱柱,乙腈–水(体积比77∶23)为流动相,蒸发光散射检测器(ELSD)检测。果糖、葡萄糖、蔗糖、麦芽糖分别在0.103 6～1.554 0,0.107 3～1.609 5,0.107 8～1.617 0,0.111 7～1.675 5μg/mL范围内有良好的线性关系,相关系数(r)分别为0.9909,0.9913,0.9999,0.9989;检出限分别为0.0104,0.0107,0.0107,0.0112μg/mL。样品中果糖、葡萄糖、蔗糖、麦芽糖的加标回收率分别为97.3%,96.6%,101.0%,97.2%,测定结果的相对标准偏差分别0.58%,0.36%,0.40%,0.28%(n=5)。实际样品检测结果显示,多批橘红丸和蜂蜜样品中4种糖含量存在明显差异,且有蜂蜜替代现象。该方法可用于橘红丸中蜂蜜辅料的质量考察。     

事蔬菜中残留三嗪农药的检测

建立了同时检测西红柿中11种三嗪除草剂残留量的高效液相色谱-紫外检测-质谱定性法.样品经纯水-甲醇提取,C12固相萃取柱净化,然后采用高效液相/紫外/质谱检测法测定,液相外标法定量.对样品前处理和色谱条件进行了研究和优化.11种三嗪除草剂在0.02×10-6～1.0×10-6 g/mL范围内的线性良好,相关系数为0.998 7～0.999 9,在0.01～0.1μg/g范围内,平均添加回收率在72.1%～101.0%,相对标准偏差为1.2%～5.1%.方法简便、快速、净化效果好.     

高效液相色谱内标法分离和测定植物中的单糖

 建立了一种以 β 吲哚乙酸为内标物 ,用高效液相色谱内标法直接分离和测定植物中游离糖的新方法。木糖、果糖、葡萄糖、蔗糖、麦芽糖、乳糖和棉子糖的分离在 18min内完成 ;检出限分别达到 1 8μg ,2 3μg ,2 7μg ,1 8μg ,3 5 μg ,4 1μg和 4 3μg ,线性范围为 5 μg/L～ 75 0 μg/L。研究了流动相中乙腈的浓度、pH值对分离 7种糖和 β 吲哚乙酸的影响。方法用于枣和苹果样品的测定并进行回收率试验 ,结果为木糖、果糖、葡萄糖、蔗糖的 5次测定的回收率分别为 97 4%～ 10 2 1% ,97 3%～ 10 1 8% ,98 7%～ 10 2 2 % ,97 7%～ 10 2 5 %,。     

Determination of reducing sugars with a 2,4-dinitrophenolate-selective membrane electrode

A 2,4-dinitrophenolate-selective liquid-membrane electrode based on tetrapentylammonium dinitrophenolate dissolved in 2-nitrotoluene is described. The electrode exhibits rapid and near- Nernstian response to the activity of 2,4-dinitrophenolate anions in the range 3×10^?5 ?1×10^?2 M. The response is unaffected by pH in the range 7.5–12.5. The electrode has been successfully applied to the kinetic potentiometric determination of fructose, glucose and galactose at 60°C and of fructose in the presence of glucose and galactose at 30°C. The electrode can be used for the potentiometric determination of glucose and fructose after completion of the reaction with excess of 2,4-dinitrophenolate ions and of sucrose after acid hydrolysis. Mixtures of glucose, fructose and sucrose in aqueous solutions or honey samples can be determined by the proposed procedures with an average error of about 2%.     

FIA determination of pyruvate in serum based on direct chemiluminescence oxidation

Chemiluminescence was observed by mixing acidic potassium permanganate solution with pyruvate in the presence of quinine. A new simplified method for pyruvate determination based on this phenomenon was established. The chemiluminescence intensity is a linear function of the concentration of pyruvate in the range of 2 × 10^–6 to 1 × 10^–3 g/mL with a detection limit of 0.8 μg/mL and a relative standard deviation of less than 2.3%. The method has been successfully used to determine pyruvate in serum. Received: 3 April 1998 / Revised: 20 July 1998 / Accepted: 17 September 1998     

A direct chemiluminescence method for the determination of nucleic acids using Ru(phen)32+–Ce(IV) system

A direct chemiluminescence method for the determination of nucleic acids has been developed based on the enhancement of nucleic acids on the chemiluminescence light emission of the reaction between Ru(phen)₃ ²⁺(phen = 1,10-phenanthroline) and Ce(IV). Under the optimum conditions, the calibration graphs are linear in the range of 5.0 × 10^–8–5.0 × 10^–5 g/mL for calf thymus DNA, 8.0 × 10^–8–5.0 × 10^–5 g/mL for fish sperm DNA and 1.0 × 10^–7–3.0 × 10^–5 g/mL for yeast RNA, respectively. The limits of detection are 1.0 × 10^–8 g/mL for calf thymus DNA, 3.1 × 10^–8 g/mL for fish sperm DNA and 5.2 × 10^–8 g/mL for yeast RNA, respectively. The final procedure allows the successful determination of calf thymus DNA, fish sperm DNA and yeast RNA in six synthetic samples. This method is simple, rapid and specific. Received: 22 January 1999 / Revised: 29 April 1999 / Accepted: 3 May 1999     

Fluorometric Determination of Fructose, Glucose, and Sucrose Using Zirconyl Chloride

Zirconyl chloride upon hydrolysis in water to form Zr(OH)⁺ has been found to react to form a fluorescent derivative with not only a ketose such as fructose but also a hexose such as glucose and the disaccharide sucrose. When reaction conditions such as a temperature of 99°C and a time of 60 min are used, detection limits below 1 μg/mL are possible. All three zirconyl–sugar derivatives show very similar absorbance and fluorescence spectra, indicating a common mechanism involving formation of an enediol which can be complexed with ZrOH⁺ is likely. Because the reactivity order is glucose < sucrose < fructose, the reaction can be made selective for fructose at a lower reaction temperature and time such as 60°C at 5 min. Because interference from ascorbic acid and caffeine is also avoided, the fluorescent determination of fructose in soft drink samples after simply a dilution step is possible. We have also employed this reaction for flow injection analysis (FIA) using a polystyrene–divinylbenzene-packed HPLC column as a mixing device. Using a 0.01 M HClO₄ with 1% zirconyl chloride carrier, we obtained a linear calibration curve from 2 to 30 μg/mL with a correlation coefficient of 0.994. A detection limit less than 2 μg/mL was possible. A comparison of results for the FIA of soft drinks with the enzymatic method involving fructose-5-dehydrogenase confirmed the FIA method was quite specific for fructose.     

Flow-injection analysis for the determination of total inorganic carbon and total organic carbon in water using the H2O2–luminol–uranine chemiluminescent reaction

In the presence of carbonate and uranine, the chemiluminescent intensity from the reaction of luminol with hydrogen peroxide was dramatically enhanced in a basic medium. Based on this fact and coupled with the technique of flow-injection analysis, a highly sensitive method was developed for the determination of carbonate with a wide linear range. The method provided the determination of carbonate with a wide linear range of 1.0 × 10⁻¹⁰–5.0 × 10⁻⁶ mol L⁻¹ and a low detection limit (S/N = 3) of carbonate of 1.2 × 10⁻¹¹ mol L⁻¹. The average relative standard deviation for 1.0 × 10⁻⁹–9.0 × 10⁻⁷ mol L⁻¹ of carbonate was 3.7% (n = 11). Combined with the wet oxidation of potassium persulfate, the method was applied to the simultaneous determination of total inorganic carbon (TIC) and total organic carbon (TOC) in water. The linear ranges for TIC and TOC were 1.2 × 10⁻⁶–6.0 × 10⁻² mg L⁻¹ and 0.08–30 mg L⁻¹ carbon, respectively. Recoveries of 97.4–106.4% for TIC and 96.0–98.5% for TOC were obtained by adding 5 or 50 mg L⁻¹ of carbon to the water samples. The relative standard deviations (RSDs) were 2.6–4.8% for TIC and 4.6–6.6% for TOC (n = 5). The mechanism of the chemiluminescent reaction was also explored and a reasonable explanation about chemical energy transfer from luminol to uranine was proposed. Figure Chemiluminescence profiles in batch system. 1, Injection of 100 μL of K₂CO₃ into 1.0 mL luminol-1.0 mL H₂O₂ solution; 2-3 and 4-5, Injection in sequence of 100 μL of K₂CO₃ and 100 μL of uranine into 1.0 ml luminol-1.0 mL H₂O₂ solution; C_luminol = 1.0 × 10⁻⁷ mol/L, C_H2O2 = 1.0 × 10⁻⁵ mol/L, C_uranine = 1.0 × 10⁻⁵ mol/L, C_K2CO3 = 1.0 × 10⁻⁷ mol/L except for 4-5 where C_K2CO3 = 1.0 × 10⁻⁴ mol/L     

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。     

A simple spectrophotometric procedure for the determination of antimony (III) and (V) in antileishmanial drugs

A spectrophotometric method for the selective determination of antimony (III) and (V) in antileishmanial drugs is described. The procedure is based on the reaction of Sb(III) with bromopyrogallol red (BPR) in neutral solution. As a consequence of the Sb-BPR complex formed, the absorbance of BPR, at 560 nm, decreases proportionally to the amount of Sb(III) in the analyte solution. The calculated apparent molar absorptivity and determination limits are 3.67 × 10⁴ L · cm^–1 · mol^–1 and 1.65 × 10^–6 mol/L, respectively. Sb(V) is determined after reduction to Sb(III) by iodide. The Sb(V) content determined in ten samples of Glucantime varied from 75.40 ± 0.97 to 94.47 ± 1.0 mg/mL. Sb(III) was detected in all samples analyzed, and mean values ranged from 5.19 ± 0.16 to 10.52 ± 0.15 mg/mL. The method is suitable for the routine quality control of pharmaceutical formulations. Received: 26 July 1996 / Revised: 17 October 1996 / Accepted: 11 December 1996     

Utilization of solid phase spectrophotometry for the determination of trace amounts of copper using 5-(2-benzothiazolylazo)-8-hydroxyquinoline

A simple, selective, highly sensitive and accurate procedure for the determination of trace amounts of copper has been developed based on solid-phase spectrophotometry. Copper reacts with 5-(2-benzothiazolylazo)-8-hydroxyquinoline (BTAHQ) to give a complex with high molar absorptivity (3.17 × 10⁷ L mol⁻¹ cm⁻¹, 3.07 × 10⁸ L mol⁻¹ cm⁻¹, 1.22 × 10⁹ L mol⁻¹ cm⁻¹, and 1.80 × 10⁹ L mol⁻¹ cm⁻¹), fixed on a Dowex 1-X8 type anion-exchange resin for 10 mL, 100 mL, 500 mL, and 1000 mL, respectively. The absorbance at 667 nm and 800 nm packed in a 1.0 mm cell was measured directly. Calibration is linear over the range 0.2–3.7 μg L⁻¹ with RSD of < 1.28 % (n = 10). The detection and quantification limits of the 500 mL sample method are 79 ng L⁻¹ and 260 ng L⁻¹ when using 60 mg of Dowex 1-X8. For a 1000 mL sample, the detection and quantification limits are 67 ng L⁻¹ and 220 ng L⁻¹ using 60 mg of the exchanger. Increasing the sample volume can enhance the sensitivity. The proposed method was applied to the determination of copper in different environmental water samples (tap, pit, spring, and river), food products (rice, corn flour, and tea), and mushrooms, using the standard addition technique.     

Chemiluminescence determination of <Emphasis Type="Italic">o</Emphasis>-chlorobenzylidenemalonic acid dinitrile in extracts

A chemiluminescence method was developed for determining o-chlorobenzylidenemalonic acid dinitrile (o-CBMA DN) in extracts. The method is based on chemiluminescence developed in a strong alkaline solution upon the interaction between 3-aminophthalic hydrazide (luminol) with the superoxide radical formed in the reaction of atmospheric oxygen activated by hemin with the products of the alkaline hydrolysis of o-chlorobenzylidenemalonic acid dinitrile and with the products of their condensation with p-nitrobenzaldehyde. The luminescence intensity of luminol was proportional to the concentration of o-CBMA DN in the range 1 × 10⁻⁶−1 × 10⁻¹ mg/mL. The determination limit for o-CBMA DN was (1 ± 0.3) × 10⁻⁶ mg/mL (p = 95%, n = 5, RSD = 29%) at 293 K.     

Sensitive fluorescent probes for determination of hydrogen peroxide and glucose based on enzyme-immobilized magnetite/silica nanoparticles

Sensitive fluorescent probes for the determination of hydrogen peroxide and glucose were developed by immobilizing enzyme horseradish peroxidase (HRP) on Fe₃O₄/SiO₂ magnetic core–shell nanoparticles in the presence of glutaraldehyde. Besides its excellent catalytic activity, the immobilized enzyme could be easily and completely recovered by a magnetic separation, and the recovered HRP-immobilized Fe₃O₄/SiO₂ nanoparticles were able to be used repeatedly as catalysts without deactivation. The HRP-immobilized nanoparticles were able to activate hydrogen peroxide (H₂O₂), which oxidized non-fluorescent 3-(4-hydroxyphenyl)propionic acid to a fluorescent product with an emission maximum at 409 nm. Under optimized conditions, a linear calibration curve was obtained over the H₂O₂ concentrations ranging from 5.0 × 10⁻⁹ to 1.0 × 10⁻⁵ mol L⁻¹, with a detection limit of 2.1 × 10⁻⁹ mol L⁻¹. By simultaneously using glucose oxidase and HRP-immobilized Fe₃O₄/SiO₂ nanoparticles, a sensitive and selective analytical method for the glucose detection was established. The fluorescence intensity of the product responded well linearly to glucose concentration in the range from 5.0 × 10⁻⁸ to 5.0 × 10⁻⁵ mol L⁻¹ with a detection limit of 1.8 × 10⁻⁸ mol L⁻¹. The proposed method was successfully applied for the determination of glucose in human serum sample.