毛细管电泳法对铝胁迫下小麦根部有机酸的直接测定

在进行植物抗铝逆性研究中,从植物的培养液中发现从根部分泌出的有机酸与铝结合从而实现无毒化是其抗铝逆性机理的重要依据,但是其分析需繁杂的前处理过程。而本文用毛细管电泳法直接测定了铝胁迫下培育的小麦根中的铝和有机酸,确认了主要积累的是苹果酸和柠檬酸。发现随着提高培养液中的铝浓度,根部的铝量也相应增加。同时,虽然根中的柠檬酸量无明显变化,但苹果酸被诱导增加。在pH7．8的Na3PO4缓冲溶液中加入表面活性剂溴化十六烷基三甲铵作为电泳溶液体系,紫外检测波长214nm,可以有效地分离检测以阴离子形式存在的上述有机酸。探讨了植物抗铝胁迫研究中简便易行的植物根部有机酸的直接测定方法。     

反相HPLC测定食物中的有机酸

本文研究了反相HPLC同时测定食物中草酸、酒石酸、苹果酸、乳酸、乙酸、柠檬酸和琥珀酸的条件,提出了用C_(18)固定相、2.5%NH_4H_2PO_4(pH2.50)溶液的流动相和在200nm下紫外检测这七种有机酸的测定方法。该法简便快速、具有较高的准确度和精密度。另外,还对有机酸的分离机理作了探讨。对十种食物中的有机酸进行了定量测定。     

石化废水中低碳有机酸的毛细管电泳分析

建立了毛细管电泳测定石化废水中低碳有机酸的方法。以25%(体积分数)甲醇-0.5 mmol/L十六烷基三甲基溴化铵-10 mmol/L邻苯二甲酸氢钾(pH 6.0))为缓冲溶液,-30 k V为分离电压,200 nm为间接检测波长,甲酸、乙酸、丙酸、丁酸、乙醇酸、乳酸、苹果酸、草酸、丙二酸、酒石酸、马来酸、丁二酸等12种有机酸达到基线分离。在试验浓度范围内,有机酸浓度与峰面积呈良好的线性关系(r在0.9981~0.9996之间)。方法回收率为91.2%~114.1%。迁移时间和峰面积的精密度(RSD)分别为0.10%~0.28%和1.6%~2.6%之间。采用电动进样模式,12种有机酸检出限低至3.2~5.6μg/L。方法已应用于石化废水中低碳有机酸的检测。     

中药中有机酸的离子色谱分析(Ⅰ)——麻黄中微量苹果酸、草酸的测定

离子色谱法是分析有机酸的一种极为有效的方法。人们在寻找新药的过程中,已在有机羧酸化合物中发现了许多新苗头。目前国内外关于中药中有机酸的离子色谱分析方面的报道极少,用离子色谱法测定麻黄中的苹果酸和草酸也未见报道,本文提出在HPIC-AS3阴离子分离柱上用NaCO,/NaOH作流动相,分离麻黄样品溶液中的苹果酸和草酸的色谱条件,建立了一个简便、快速、准确的分析中药中苹果酸和草酸的离子色谱方法。为医学界研究中药中有机酸的含量提供了一种快速的分     

离子色谱法测定威力酸中的有机酸

采用离子排斥分离,电导检测模式,对威力酸中的4种有机酸成份进行分离测定。将威力酸样品通过萃取、洗涤、过滤之后进样,可以测定其柠檬酸、乳酸、苹果酸、富马酸4种有机酸,在一定的色谱条件下,4种阴离子都具有很好的线性和较低的检出限。威力酸中的柠檬酸,乳酸,苹果酸,富马酸的检出限分别是0.10、0.14、0.30和0.12μg/L,线性相关系数r2在0.9997~0.9999范围内,样品中待测离子峰面积的RSD在4.3%以下(n=10),回收率在94%~105%之间。采用抑制电导的离子色谱法是分析威力酸中的有机酸成份的高效与准确的方法。     

毛细管电泳在低分子量有机酸分析中的应用

本文介绍了低分子量有机酸的毛细管电泳研究方法。着重总结了各种分离模式和检测方法,并评述了近五年来,毛细管电泳在食品和环境中有机酸分析的应用进展。引用文献70篇。     

毛细管电泳-间接紫外检测法分离和测定食品中的有机酸

有机酸毛细管电泳（CE）分析是90年代初首先被报道的[1],近年来有了较大的发展[2]．采用CE法可进行不同基质样品如食品、饮料、尿液等样品中多种有机酸的同时分析[1,3,4]．该法采用CE的阴离子分离模式,在电解质溶液中加入电渗流改性剂,使电渗流方向逆向,从而与阴离子的电泳方向一致,以缩短分析时间．常见有机酸在200um以上大多无紫外吸收,一般采用间接紫外检测方法[1,3],也可采用低波长紫外检测[4]．低分子量阴离子的CE研究报道不多[5,6],有机酸的CE分离系统研究尚未见报道．本文系统地研究了毛细管电泳-间接紫外检测法分析…     

淋洗液自动发生-离子色谱法同时测定食品中的21种有机酸

建立了一种利用离子色谱法同时测定样品中奎尼酸、乙酸、丙酮酸、草酰乙酸、甘露酸、乳酸、琥珀酸、苹果酸、酒石酸、草酸、富马酸、抗坏血酸、α-酮戊二酸、肉桂酸、水杨酸、柠檬酸、异柠檬酸、阿魏酸、顺乌头酸、反乌头酸、β-香豆酸等21种有机酸的方法。样品经提取、脱色、过滤后用IonPac AS11分离柱分离,以EG40自动淋洗液发生器生成的5~34 mmol/L KOH为淋洗液洗脱,抑制电导检测器检测。21种有机酸的浓度与其峰面积在一定的范围内呈良好的线性关系,检出限均低于0.188 mg/L,加标回收率为91.5%~101.8%。该法用于多种食物样品中有机酸的测定,结果令人满意。     

固相萃取-高效液相色谱法测定蜂蜜中的有机酸

建立了固相萃取-高效液相色谱(SPE-HPLC)同时测定蜂蜜中5种有机酸(L-苹果酸、马来酸、琥珀酸、柠檬酸、D-苹果酸)含量的方法。蜂蜜经制样后过Bond Elutes SAX固相萃取(SPE)小柱净化,用C18-MS-II反相色谱柱(250 mm×4.6 mm, 5 μm)进行分离,流动相为2%偏磷酸溶液,流速为0.7 mL/min,检测波长为210 nm。在此条件下5种有机酸在相应的线性范围内其线性相关系数均大于0.9967;方法的回收率为86.0%～103.9%,相对标准偏差为5.7%～9.8%(n=6),检出限为0.06～9.4 mg/kg。所建立的方法可用于蜂蜜样品中有机酸的测定。     

烟草中9种有机酸的梯度离子色谱法测定研究

采用淋洗液自动发生一梯度离子色谱分离,电导检测法分离测定了烟草中的甲酸、乙酸、乳酸、丙酸、丁酸、苹果酸、丙二酸、草酸和柠檬酸,并研究了9种有机酸在阴离子交换色谱中的保留行为.以淋洗液自动发生器生成的KOH为淋洗液,样品经提取、过滤稀释后,在IonPac AS1l-HC阴离子交换色谱柱上分离,抑制电导检测器进行检测,一次...     

Enantioseparation of α‐hydroxy acids by chiral ligand exchange CE with a dual central metal ion system

Using two kinds of central metal ions in a background electrolyte, ligand exchange CE was investigated for the simultaneous enantioseparation of dl ‐malic, dl ‐tartaric, and dl ‐isocitric acids. Ligand exchange CE with 100 mM d ‐quinic acid as a chiral selector ligand and 10 mM Cu(II) ion as a central metal ion could enantioseparate dl ‐tartaric acid but not dl ‐malic acid or dl ‐isocitric acid. A dual central metal ion system containing 0.5 mM Al(III) ion in addition to 10 mM Cu(II) ion in the background electrolyte enabled the simultaneous enantioseparation of the three α‐hydroxy acids. These results suggest that the use of a dual central metal ion system can be useful for enantioseparation by ligand exchange CE.     

逐级提取-高效液相色谱法快速测定植物组织中8种有机酸

针对植物组织中草酸存在的不同形态,建立了水和稀盐酸作为提取介质的逐级提取方法,获得了水溶态和酸溶态草酸及乙醇酸、乙醛酸、酒石酸、苹果酸、乙酸、柠檬酸、琥珀酸等有机酸。采用Hypersil ODS (200 mm×4.6 mm, 5 μm)色谱柱,以5 mmol/L磷酸二氢钾水溶液(pH 2.8)作为流动相,在进样量5 μL、检测波长210 nm、柱温30 ℃的条件下,通过分时段控制流速实现了8种有机酸的快速分离,同时去除了盐酸对酸溶态草酸测定的干扰。本方法精确灵敏、回收率高、重复性好,可应用于实际样品的测定分析。     

离子排斥色谱法测定生脉注射液中的有机酸

1引言生脉注射液是由红参、麦冬和五味子3种药材经提取后制成的灭菌水溶液,为国家中药保护品种,具有益气养阴,复脉固脱的功效。前期的分析实验表明,生脉注射液中含有有机酸类成分。根据生脉注射液的生产工艺和3种药材的的化学成分研究报道,分析生脉注射液中的有机酸主要来源于五味子。五味子含有柠檬酸、苹果酸、琥珀酸等多种有机酸成分。目前,有机酸的分析方法有气相色谱法[1]、高效液相色谱法[2]、毛细管电泳法[3]及离子色谱法[4]。这些方法专属[5]     

离子排斥色谱法分离分析若干有机酸

本文报道利用高效离子排斥色谱(HPICE)研究了脂肪族一元和二元羧酸的分离分析方法。成功地分析了苹果酸合成工艺中试样的苹果酸含量及杂质。     

Peroxidase based biosensors for the selective determination of D,L-lactic acid and L-malic acid in wines

A novel bioelectrochemical method for the direct determination of D(−) L(+) lactic acid and of L(−) malic acid in wines is presented. Multienzymatic biosensors were realized for the selective determination of the three analytes: D(−) and L(+) lactic acid were measured by a trienzymatic biosensor based on the catalytic activities of the enzymes L(+) lactate oxidase (LOD), D(−) lactate dehydrogenase (D-LDH) and horseradish peroxidase (HRP); L(−) malic acid was measured by a bienzymatic electrode, realized by coupling the enzymes L(−) malic dehydrogenase (L-MDH) and horseradish peroxidase (HRP). In both cases the enzymes were immobilized on an oxygen selective Clark electrode.The simultaneous determination of the two organic acids can be accomplished either in batch or in a flow injection analysis apparatus using the same biosensors as detectors. The analytical performance of the method, tested in standard aqueous solutions and on real samples of wines, showing high repeatability, short response times and reduced cost of analysis, suggest that the experimental approach here described could be followed to monitor the progress of malolactic fermentation.     

离子色谱法同时测定胞外培养液中的有机酸与核苷酸

建立了一种利用阴离子交换色谱柱分离,抑制型电导检测器同时测定乳酸、丙酸、丙酮酸、苹果酸、磷酸二羟丙酮、柠檬酸、异柠檬酸7种有机酸和单磷酸核苷酸(AMP)、双磷酸核苷酸(ADP)、三磷酸核苷酸(ATP)3种核苷酸的方法。采用IonPacAS11-HC阴离子交换柱,KOH梯度洗脱,流速1.00mL/min,柱温30℃,进样体积25μL。方法的相对标准偏差为0.39%～4.69%,线性相关系数为0.9906～0.9996,加标回收率为80.71%～94.02%,方法可用于嗜热厌氧菌胞外培养液中有机酸和核苷酸的同时测定。     

高效液相色谱法测定果酸

本文研究了反相高效液相色谱法同时分离和测定6种果酸的色谱条件,提出了有效提取果酸的方法,并对苹果梨、香水梨等样品进行了实际分析。结果表明,该法简更快速,具有较高的准确度和精密度。     

Interaction between low molecular weight organic acids and hydroxyapatite with different degrees of crystallinity

In this study, two types of hydroxyapatite (HAP) with different degrees of crystallinity were prepared by a sol-gel method and a chemical precipitation method. Influences of crystallinity on the adsorption and dissolution properties of HAP, and the release of phosphorus (total phosphorus) during the adsorption of organic acid were investigated. Results showed that crystallinity had a great effect on the adsorption capacity and dissolution properties of HAP, as well as the adsorption mechanisms of organic acids on HAP surfaces. The poorly crystallized (the degree of crystallinity X_c = 0.23) HAP adsorbed greater amounts of oxalic, citric, or malic acid than the well crystallized (X_c = 0.86) HAP, and the former could release more phosphorus in the presence of organic acids. The adsorption capacity of oxalic acid was much higher than citric and malic acids on both the well and the poorly crystallized HAP, which was due to the strong coordination of oxalic acid with calcium on HAP surface, and that physical adsorption was more inclined to dominate the adsorption of malic or citric acid on the well crystallized HAP. These findings might be of importance in understanding the effects of crystallinity and organic acid binding on the dissolution of calcium phosphates and the adsorption characteristics of HAP.     

Simultaneous Determination of Organic Acids in Wine Samples by Capillary Electrophoresis and UV Detection: Optimization with Five Different Background Electrolytes

A simple technique is described for the routine capillary electrophoretic determination of organic acids in wine samples. Several aromatic and non‐aromatic compounds, including phthalic acid, benzoic acid, sorbic acid, boric acid, and phosphate, were evaluated as background electrolytes in order to obtain the highest resolution and detection sensivity. Factors that affect capillary electrophoretic separation such as the concentration and pH of the background electrolyte (BGE), the concentration of the electroosmotic flow modifier (EOF), and methanol addition to the electrolyte were investigated systematically. Tartaric, malic, succinic, acetic, and lactic acids were determined simultaneously in approximately six minutes using an electrolyte containing 3 mM phosphate and 0.5 mM myristyltrimethylammonium bromide (MTAB) as electroosmotic flow modifier at pH 6.5. This method is quantitative, with recoveries in the 90–102% range and linear up to 50 mg L^–1. The precision is better than 1% and the procedure shows the appropriate sensibility, with detection limits between 0.015 and 0.054 mg L^–1. The proposed method was successfully employed for the determination of organic acids in wine samples by direct sample injection after appropriate dilution and filtration.