反相流动注射-化学发光法测定氨基酸

1　引　　言氨基酸是组成蛋白质的基本单元 ,是合成人体中各种酶、激素和抗体的重要物质 ,氨基酸在人体中含量的多少直接影响到人体的健康。目前测定氨基酸的方法主要有采用经液相色谱分离后再用分光光度法、荧光法检测其衍生物的方法 ,但衍生反应操作复杂且测定灵敏度较低 ;用氨基酸分析仪测定氨基酸可获得较高的灵敏度 ,但由于仪器设备价格昂贵 ,需专业人员操作且操作复杂 ,难以在中小型企业普及 ,限制了它们的广泛应用。此外 ,还有电化学、化学发光等方法 ,采用铁氰化钾 鲁米诺体系测定多种氨基酸的方法尚未见报道。2　实验部分2 .1　仪…     

反相流动注射-化学发光法测定苯胺

在酸性介质中,苯胺与过量亚硝酸盐重氮化,剩余亚硝酸盐快速氧化亚铁氰化钾,生成的铁氰化钾与鲁米诺发生化学发光反应。据此,建立了反相流动注射 化学发光法测定苯胺的新方法。方法的线性范围为0 070～10.0mg L,检出限为0 03mg L,相对标准偏差(n=11,ρ=1.0mg L)为2 0%。方法已用于环境水样中苯胺的测定。     

反相流动注射化学发光法测定草甘膦

在酸性介质中,草甘膦与过量的NO2^-反应生成稳定的N－亚硝胺,而剩余的NO2^-快速氧化亚铁氰化钾为铁氰化钾,与鲁米诺－铁氰化钾化学 光反应相偶合,据此,建立了反相流动注射化学发光法测定草甘膦的新方法,该方法的线性范围为0．10－5．00mg/L^-1,检出限为0．05mg.L^01,相对标准偏差为0．6％,该方法用于废水中草甘膦的测定,回收率为96－106％。     

反相流动注射化学发光法测定葡萄糖

提出使用葡萄糖增强Ｌｕｍｉｎｏｌ－Ｋ７Ｃｕ（ＩＯ６）２－ＫＯＨ化学发光体系，结合高灵敏度的反相流动注射技术进行葡萄糖的测定。本法不仅节省试剂，而且操作简单，重复性好。葡萄糖在４×１０－７～８×１０－５ｍｇ／Ｌ浓度范围内与化学发光分析信号呈线性关系；检出限为１．８Ｘ１０－７ｍｇ／Ｌ；ＲＳＤ＝２．０４％。     

反相流动注射-化学发光法测定氢化可的松

在碱性介质中,氢化可的松可被Fe(CN)6^3-氧化产生化学发光,奎宁对此发光反应有显著的增敏作用。据此,建立了反相流动注射-化学发光法测定氢化可的松的新方法。方法的线性范围和检出限分别为0．05．-50mg／L和0．02mg／L,相对标准偏差(n=11,C=1．0mg／L)为0．9％。方法用于药物中氢化可的松含量的测定,结果与标准方法分光光度法测定结果吻合。     

反相流动注射化学发光法测定单宁

在碱性介质中 ,单宁对高碘酸钾氧化鲁米诺的化学发光反应有较强的增敏作用 ,据此建立了反相流动注射化学发光测定单宁的新方法 ,并研究了最佳反应条件。该方法快速、准确、线性范围宽 ,测定单宁的检出限为 1 .1 2× 1 0 - 9g/ m L,方法的线性范围为 2 .0× 1 0 - 8～ 6 .0× 1 0 - 6 g/ m L,对于 4.0× 1 0 - 6 g/ m L单宁 1 0次测定的相对标准偏差为 0 .79%。应用于中药五倍子、诃子中单宁的测定 ,结果满意     

高灵敏反相流动注射化学发光法测定抗坏血酸

基于抗坏血酸对Ｆｅ２＋－Ｌｕｍｉｎｏｌ－Ｏ２体系化学发光的抑制效应，利用反相流动注射技术，建立了一个测定抗坏血酸的高灵敏化学发光新方法。该法检出限达２×１０－１０ｇ／ｍＬ；抗坏血酸浓度在 １×１０－９～１× １０－６ｇ／ｍＬ范围内与体系化学发光强度减小量呈良好线性相关；相对标准偏差为１．９％（Ｃ＝５×１０－８ｇ／ｍＬ，ｎ＝１１）。     

反相流动注射化学发光法测定黄芩苷

在碱性介质中,K3Fe(CN)6氧化鲁米诺产生化学发光,黄芩苷对该体系化学发光具有强烈的抑制作用。利用该化学发光的抑制体系,结合反相流动注射技术,建立了测定黄酮类药物黄芩苷含量的新方法。在优化的条件下,黄芩苷浓度在1.0×10-8～1.0×10-7和3.0×10-7～4.0×10-6mol/L范围内与化学发光抑制强度ΔI呈良好的线性关系,检出限为1.0×10-9mol/L,对3.0×10-7mol/L的黄芩苷进行平行测定10次,得相对标准偏差(RSD)为1.7%。该方法可应用于银黄口服液中黄芩提取物(黄芩苷计)的含量测定。     

反相流动注射抑制化学发光法测定头孢唑啉钠

基于头孢唑啉钠能抑制磷钼钒杂多酸氧化鲁米诺产生化学发光,结合流动注射分析技术,提出了测定头孢唑啉钠的化学发光新体系。头孢唑啉钠在3.0×10-7~8.0×10-5 g/mL质量浓度范围内与化学发光信号呈线性关系;检出限为8.0×10-8 g/mL;对5.0×10-6 g/mL的头孢唑啉钠进行11次连续测定,相对标准偏差为3.8%。该方法快速、灵敏,已经被成功地应用于头孢唑啉钠针剂的测定。     

高灵敏反应流动注射化学发光法测定抗坏血酸

基于抗坏血酸对Ｆｅ＾２＋－Ｌｕｍｉｎｏｌ－Ｏ２体系化学光的抑制效应，利用反应相流注射技术，建立了一个测定抗坏血酸的高灵敏化学发光新方法。该法检出限达２＊１０＾－１０ｇ／ｍＬ；抗坏血酸浓度在１＊１０＾－９－１＊１０＾－６ｇ／ｍＬ范围内与体系化学发光强度减小量呈良好线性相关；相对标准偏差为１．９％。     

流动注射化学发光法测定己内酰胺

使用己内酰胺增强Ce(Ⅳ) SO32-化学发光体系,结合流动注射分析技术进行了己内酰胺的测定。己内酰胺的质量浓度在4.0×10-7～1.0×10-5g/mL范围内与化学发光分析信号呈线性关系,其检出限为1×10-7g/mL。对4.0×10-7g/mL的己内酰胺溶液进行11次连续测定,相对标准偏差为2.1%。方法已应用于层析用聚己内酰胺中的己内酰胺测定。     

Selective determination of amino acids using flow injection analysis coupled with chemiluminescence detection

The determination of the amino acids proline, histidine, tyrosine, arginine, phenylalanine and tryptophan using flow injection analysis (FIA) with chemiluminescence detection is described. Proline was the only amino acid to exhibit chemiluminescence with the tris(2,2-bipyridyl)ruthenium(III) reaction at pH 10. While, histidine was found to selectively enhance the reaction of luminol with Mn(II) salts in a basic medium. Acidic potassium permanganate chemiluminescence was able to selectively determine tyrosine at pH 6.75. Low pressure separations using a C18 guard column allowed the simultaneous determination of tyrosine and tryptophan or phenylalanine and tryptophan with acidic potassium permanganate and copper(II)-amino acid-hydrogen peroxide chemiluminescence, respectively. Precision for each method was less than 3.9% (R.S.D.) for five replicates of a standard (1×10⁻⁵ M) and the detection limits ranged between 4×10⁻⁹ and 7×10⁻⁶ M. Preliminary investigations revealed that the methodology developed was able to selectively determine the individual amino acids in an equimolar mixture of the 20 naturally occurring amino acids.     

流动注射化学发光抑制法测定阿魏酸钠

提出了Fe2+-H2O2-亚甲基蓝化学发光新体系并用于阿魏酸钠的测定。实验发现,在酸性介质中,Fe2+-H2O2体系可与亚甲基蓝反应产生极强的化学发光,阿魏酸钠对此化学发光具有显著的抑制作用。据此,结合流动注射技术,建立了阿魏酸钠化学发光分析新方法。研究了影响化学发光强度的因素,化学发光信号的降低值(ΔI)与阿魏酸钠浓度在4.5×10-6～4.5×10-5mol/L范围内呈良好的线性关系,方法的检出限为7.0×10-7mol/L。对4.8×10-6mol/L的阿魏酸钠进行了11次平行测定,其RSD=0.8%,该法已用于片剂中阿魏酸钠含量的测定。     

Direct determination of amino acids by pressurized capillary electrochromatography with chemiluminescence detection

A pressurized CEC (pCEC) coupled with on-column chemiluminescence (CL) detection was developed for direct determination of amino acids, which was based on the principle of an enhanced effect of Cu(II)-amino acid complexes on the CL reaction between luminol and hydrogen peroxide in alkaline solution. The effects of some important factors on pCEC separation and CL intensity were systemically investigated. Baseline separation of amino acids including L-histidine (L-His), L-threonine (L-Thr), and L-tyrosine (L-Tyr) was achieved by using a monolithic column with a mobile phase of 5.0x10(-3) mol/L phosphate buffer at pH 8.0 that contained 25% v/v methanol and 5.0x10(-4) mol/L luminol and 1.0x10(-5) mol/L Cu(II) at an applied voltage of -5 kV. The calibration curves of the analytes by plotting the peak height against corresponding concentration were linear over the range of 3.2x10(-6)-3.2x10(-4) mol/L for L-His, 4.1x10(-6)-4.1x10(-4) mol/L for L-Thr, and 6.0x10(-7)-3.0x10(-4) mol/L for L-Tyr. The LODs for L-His, L-Thr, and L-Tyr were 6.4x10(-7), 8.4x10(-7), and 3.0x10(-7) mol/L (S/N = 2), respectively. The proposed method was applied to the analysis of amino acid injection sample with satisfactory results. Mean recoveries for three amino acids were from 84.3 to 89.6%.     

Chemiluminescence determination of 20 amino acids and the mechanism study

<正>It was found that 20 amino acids could inhibit the intensity of the luminol-H_2O_2-CuSO_4 chemiluminescence system.Using this character,a rapid and sensitive method for the determination of 20 amino acids was developed with flow injection coupled with chemiluminescence detection.Under the optimal conditions,the detection limits of 20 amino acids were in the range of 4.5×10~(-7)- 4.3×10~(-10) mol/L,and the relative standard deviations were less than 3.2%.The proposed method was successfully applied to drug analysis.The possible mechanism was also discussed.     

Determination of pipemidic acid based on flow-injection chemiluminescence due to energy transfer from peroxynitrous acid synthesized on-line

A flow-injection chemiluminescence (CL) method for the determination of pipemidic acid is described. It is based on energy transfer from excited state peroxynitrous acid to pipemidic acid, in which the excited state peroxynitrous acid is synthesized on-line by the mixing of acid hydrogen peroxide with nitrite in a flow system and the CL is from two excited states of pipemidic acid. The proposed method allows the measurement of pipemidic acid over the range of 2.0×10^–7–2.0×10^–5 mol l^–1 . The detection limit is 6.3×10^–8 mol l^–1, and the relative standard deviation for 2.0×10^–6 mol l^–1 pipemidic acid (n= 9) is 0.9%. This method was evaluated by the analysis of pipemidic acid in pharmaceutical preparations.     

流动注射胶束化学发光法测定西咪替丁的研究

在碱性条件下K3Fe(CN)6可直接氧化西咪替丁产生化学发光信号,吐温-80的存在可大大增强此反应的化学发光强度。基于此,建立了胶束流动注射化学发光法测定西咪替丁的新方法。在优化的实验条件下,该法的线性范围为1.0×10-7~5.0×10-4g/mL,检出限为2×10-8g/mL,相对标准偏差为1.6%(n=11,ρ=5.0×10-7g/mL)。该法已用于西咪替丁制剂中西咪替丁的测定。     

流动注射结合化学发光法测定没食子酸

基于没食子酸与铬 (Ⅵ )的氧化还原反应 ,产生的铬 (Ⅲ )催化鲁米诺 H2 O2 化学发光体系的研究 ,结合流动注射技术 ,优化反应条件 ,建立了一种高灵敏度的快速测定没食子酸的新方法。方法的线性范围为 2 .0× 1 0 - 9～ 5 .0× 1 0 - 6g/mL ,检出限为 1 .2× 1 0 - 9g/mL ,对 1 .0× 1 0 - 7g/mL的没食子酸进行了 1 1次平行测定 ,相对标准偏差为 2 .1 %。方法成功地用于健民咽喉片中没食子酸的测定。     

流动注射化学发光法测定褪黑素

在强碱性介质中,铁氰化钾可直接氧化褪黑素产生化学发光。基于此,建立了一种测定褪黑素的流动注射化学发光分析方法。线性范围为1.9×10-6~2.3×10-4g/mL,检出限为5×10-7g/mL,该法已用于药物中褪黑素的测定。