高效毛细管电泳技术同时检测随机尿中香草扁桃酸、高香草酸和肌酐含量

目的 建立高效毛细管电泳技术快速检测随机尿中香草扁桃酸(vanillylmandelic acid,VMA)、高香草酸(homovanillic acid,HVA)和肌酐(creatinine,Cr)的方法.方法 在毛细管区带电泳模式下,以120 mmol/L NaH_2PO_4-Na_2HPO_4(pH值6.80)为缓冲液,在非涂层石英毛细管(47 cm×75μm内径)中进行电泳.样品离心后直接稀释压力进样4 s,20 kV电压分离后通过二极管阵列检测器(DAD)检测(λ=200 nm).对该法进行系统的方法学评价后,测定健康成人及儿童随机尿标本各100份,建立成人与儿童尿VMA/Cr、HVA/Cr参考值.结果尿中VMA、HVA和Cr在13 min内出峰.VMA、HVA和Cr分别在0～500、0～500、0～4 000 μmol/L范围内呈良好的线性,相关系数(r)在0.997 2～0.999 1之间(P<0.01),检出限(S/N=3)分别为1.0、1.0和50.0 μmol/L.尿中VMA、HVA和Cr迁移时间的平均批内(n=10)变异系数(CV)分别为0.58%、0.56%和0.25%,平均批间(n=10)CV分别为0.95%、1.00%和0.48%;峰面积的平均批内(n=10)CV分别为3.78%、3.97%和2.76%,平均批间(n=10)CV分别为4.60%、4.08%和4.42%.VMA、HVA和Cr平均回收率分别为98.36%、93.56%和98.85%.儿茶酚胺、5-羟色胺和清蛋白等对测定结果无干扰.该法与HPLC法有较好的相关性,VMA、HVA浓度的相关系数(r)分别为0.954 9(P<0.01)和0.945 1(P<0.01).健康成人与儿童随机尿标本的VMA/Cr、HVA/Cr比值均呈偏态分布(n=100),以百分位数法建立其95%参考值,成人VMA/Cr、HVA/Cr分别为0～4.26和0～1.69(μmol/mmol),儿童VMA/Cr、HVA/Cr分别为0～10.39和0～4.31(μmol/mmol).结论 该法可同时检测随机尿中VMA、HVA和Cr,样品用量少,且稀释后直接进样,操作简便、快速,准确度和精密度高,易于自动化,是尿液VMA、HVA常规检测及相关疾病筛查的理想方法.     

高效液相色谱法测定香草扁桃酸、高香草酸、肌酐含量

目的建立高效液相色谱法同时测定尿中的香草扁桃酸（ＶＭＡ）、高香草酸（ＨＶＡ）和肌酐（Ｃｒ）含量的方法。方法以０．０２ｍｏｌ／ＬＫＨ２ＰＯ４缓冲液（ｐＨ５．７）为流动相；色谱柱采用ＹＷＧ－Ｃ１８柱；电化学和紫外检测器联合检测。尿样经适当稀释后直接进样测定，最后以ＶＭＡ和ＨＶＡ与Ｃｒ的比值表示含量。对１５例正常成人和１０例嗜铬细胞瘤患者进行了测定。结果方法的平均批内变异系数（ＣＶ）值ＶＭＡ／Ｃｒ为２．４％，ＨＶＡ／Ｃｒ为６．１％。正常成人的ＶＭＡ／Ｃｒ和ＨＶＡ／Ｃｒ分别为３．８４×１０－３±０．９１×１０－３（ｍｍｏｌ／ｍｍｏｌ）和３．３１×１０－３±１．１３×１０－３（ｍｍｏｌ／ｍｍｏｌ）；嗜铬细胞瘤患者的ＶＭＡ／Ｃｒ和ＨＶＡ／Ｃｒ分别为２８．７０×１０－３±２５．４６×１０－３和４．３８×１０－３±２．０８×１０－３（ｍｍｏｌ／ｍｍｏｌ）。结论方法能满足临床诊断嗜铬细胞瘤和神经母细胞瘤的需要     

高效液相色谱法测定香草扁桃酸,高香草酸,肌酐含量

目的 液相色谱法同时测定尿中的香草扁桃酸（ＶＭＡ）、高香草酸（ＨＶＡ）和肌酐（Ｃｒ）含量的方法。方法以０．０２ｍｏｌ／ＬＫＨ３ＰＯ４缓冲液（ＰＨ５．７）为流动相；色谱柱有杉ＹＷＧ－Ｃ１８柱；电化学和紫外检测器联合检测。悄样经适当稀释的直接进样测定，最后以ＶＭＡ和ＨＶＡ与Ｃｒ的比值表示含量。对１５例正常成人和１０例嗜铬细胞瘤患者进行了测定。结果方法的平均批内变异系数（ＣＶ）值ＶＭＡ／Ｃｒ为２．４％，     

应用高效毛细管电泳技术快速分离尿肌酐

目的建立1种快速测定尿中肌酐浓度的毛细管电泳方法.方法用pH2.5、0.1 mmol/L磷酸作为电泳缓冲液,利用非涂层石英毛细管48.5 cm×50 μm(id),采用外标法定量,检测波长191 nm.结果本法在34.5～8 840 μmol/L浓度范围内呈良好的线性(r=0.998),日内和日间变异系数分别为3.5%、6.2%,平均回收率94.7%.与苦味酸法有良好的相关性(Y=1.004X+0.004,r=0.998,n=45).结论本法线性范围宽、简单、快速,可应用于临床样品的检测.     

应用高效毛细管电泳技术快速分离尿肌酐

目的　建立 1种快速测定尿中肌酐浓度的毛细管电泳方法。方法　用pH2 .5、0 .1mmol/L磷酸作为电泳缓冲液 ,利用非涂层石英毛细管 48.5cm× 5 0 μm(id) ,采用外标法定量 ,检测波长 191nm。 结果　本法在34 .5～ 8840 μmol/L浓度范围内呈良好的线性 (r =0 .998) ,日内和日间变异系数分别为 3.5 %、6 .2 %,平均回收率 94.7%。与苦味酸法有良好的相关性 (Y =1.0 0 4X 0 .0 0 4,r =0 .998,n =45 )。结论　本法线性范围宽、简单、快速 ,可应用于临床样品的检测。     

随机尿和24小时尿测定香草扁桃酸对临床诊断的比较

香草扁桃酸(VMA)为儿茶酚胺(肾上腺素、去甲肾上腺素)的代谢产物,临床主要用于诊断嗜铬细胞瘤和神经母细胞瘤,现在通过用微柱比色法分别对15例患者及15例健康者的随机尿和24小时尿VMA进行检测,比较随机尿VMA/Cr与24小时尿VMA两种方法敏感性和特异性。     

毛细管胶束电动色谱法检测尿液肌酸和肌酐含量

目的 建立高效毛细管电泳技术（HPCE）测定尿液中肌酸（Cri）和肌酐（Cr）的方法。 方法 运用毛细管胶束电动色谱技术（MEKC）,以pH 5.5、20 mmol/L的Na₂HPO₄-H₃PO₄（含100 mmol/L SDS）作为电泳缓冲液,非涂层石英毛细管进行分离,样品经过20倍稀释后以1 psi压力进样4 s,15 kV电压下分离尿液中的Cri和Cr,二极管阵列检测器（DAD）（λ=200 nm）检测。 结果 Cri和Cr的线性范围为4.9~2 500 μmol/L和4.9~2 500 μmol/L（r值分别为0.999 8和1）; Cri回收率为97.8%~100.8%、平均99.2%,Cr回收率为99.5%~104%、平均101.8%;Cri迁移时间批内和批间差异（CV）平均值为3.2%和8.0%、Cr为2.3%和6.8%;Cri和Cr的最低检出限分别为1.4 μmol/L和3.31 μmol/L。 结论 本法标本用量小、干扰因素少、精密度和准确度高、线性范围宽、测定成本低廉,可满足临床常规检测要求。     

打鼾患者尿香草扁桃酸水平与夜间低氧血症的关系

目的 :了解打鼾者夜间低氧血症对尿香草扁桃酸 (VMA )水平的影响。方法 :采用病例 -对照的研究方法 ,分别收集打鼾合并夜间低氧血症的患者和打鼾血氧饱和度正常者夜间 8h尿液和 2 4h总尿液。夜间低氧血症分度 :SaO2 ≥ 94%为正常组 ,85 %≤SaO2 <94%为轻度低氧血症组 ,65 %≤SaO2 <85 %为中度低氧血症组 ,SaO2 <65 %为重度低氧血症组。尿VMA的测定采用重氮显色法。结果 :( 1) 8h尿VMA的水平和 2 4h时尿VMA的水平在正常血氧饱和度组、轻度低氧血症组、中度低氧血症组均呈递增的趋势 ,且存在统计学差异 (P <0 0 5 )。 ( 2 )单因素相关性分析结果显示 ,夜间 8h尿VMA与夜间最低血氧饱和度的相关系数为 -0 19,且差异具有显著意义 (P=0 0 40 ) ;2 4h尿VMA与夜间最低血氧饱和度的相关系数为 -0 15 ,且差异具有显著意义 (P =0 0 48)。结论 :研究结果提示 ,轻、中度缺氧的打鼾患者尿VMA水平随血氧饱和度的降低而增高     

尿肌酐的毛细管电泳测定

本文采用外标法建立了直接定量测定尿肌酐的高效毛细管电泳新方法。该方法的线性范围为32～8000μmol／L，最低检测限11μmol／L。本法的批内和日间变异系数分别小于3．6％和4．2％，肌酐的回收率为98．8％～104．6％。内生性化合物和常用药物对该方法无干扰，该方法线性范围宽，简单快速，适用于临床检验。     

Simultaneous liquid-chromatographic determination of urinary vanillylmandelic acid, homovanillic acid, and 5-hydroxyindoleacetic acid

We describe a liquid-chromatographic method for quantifying, simultaneously by a single procedure, vanillylmandelic acid (VMA), homovanillic acid (HVA), and 5-hydroxyindoleacetic acid (5-HIAA) in urine. After solvent extraction of acidified urine, the analytes were chromatographed on a C8 column, with use of a mobile phase of phosphate buffer (20 mmol/L, pH 4.0) and methanol with a variable gradient elution, and detected fluorometrically. We report the analytical recovery, sensitivity, precision, working linear range, and potential for interference from similar molecules or drugs. The results of such tests demonstrate that the proposed method is sensitive and reproducible. It is, furthermore, easy to perform, and thus is suitable for use in the clinical laboratory.     

Simultaneous determination of proline and pipemidic acid in human urine by capillary electrophoresis with electrochemiluminescence detection

Pipemidic acid is extensively used in the treatment of Gram‐negative urinary tract infections, and the contents of proline in human urine vary in association with chronic uremia. The simultaneous determination of pipemidic acid and proline in human urine is of significance for quality control of the dosage and clinical study. The coupling of Ru(bpy)‐based electrochemiluminescence detection with capillary electrophoresis was developed for the simultaneous determination of proline and pipemidic acid in human urine. Parameters related to the separation and detection were investigated and optimized. The standard curves were linear between 0.1 and 90 µg mL^?1 for proline and between 0.4 and 100 µg mL^?1 for pipemidic acid. Underop‐timized conditions, the detection limits (3σ) were 0.02 µg mL^?1 for proline and 0.06 µg mL^?1 for pipemidic acid. Relative standard derivations for the electrochemiluminescence intensity and the migration time were 3.2 and 0.9% for proline and 3.7 and 1.2% for pipemidic acid, respectively. The developed method was successfully applied to determine proline and pipemidic acid in human urine. The result showed that the content and decreasing rates of proline in urine for male were higher than that for female, and the content and decreasing rate of pipemidic acid in urine for male and female were consistent, respectively. J. Clin. Lab. Anal. 24:327–333, 2010. © 2010 Wiley‐Liss, Inc.     

Liquid-chromatographic determination of vanillylmandelic acid in urine

Urinary vanillylmandelic acid (VMA) was determined by "high-performance" liquid chromatography with fluorometric (LC-F) and amperometric (LC-EC) detection. Urine samples were first purified on a small, open-bed, reversed-phase preparatory column. VMA and the internal standard (iso-VMA) were then separated by reversed-phase ion-pair liquid chromatography. Analytical recovery of VMA was high (98.3%, SD 3.3%, n = 8), and concentrations measured by LC-F and LC-EC were in excellent agreement (r = 0.996). The LC-F chromatograms of urine samples had fewer late peaks; however, detection limits were lower (15 vs 120 micrograms/L) for the LC-EC method. Typical concentrations of 1-10 mg/L in urine can be measured easily with either method.     

Determination of urinary vanillylmandelic acid and homovanillic acid by high performance liquid chromatography for mass screening of neuroblastoma

In order to develop a mass screening method for the early detection of neuroblastoma, we measured urinary vanillylmandelic acid (VMA) and homovanillic acid (HVA) by a high performance liquid chromatography (HPLC) equipped with an electrochemical detector. Urinary samples were collected on a piece of filter paper and then pre-treated by a simple method. Measurement of VMA and HVA was performed within a short period of time, and by about 80 samples per a day could be analyzed by automatic system. The method described herein proved to be reliable, and we thus recommend it as a useful method for measurement of both VMA and HVA, leading to more accurate detection of neuroblastoma in mass screening test.     

A rapid and simple gas-liquid chromatographic procedure for homovanillic and vanillylmandelic acid in urine

A rapid and simple procedure for the determination of vanillylmandelic acid and homovanillic acid by gas—liquid chromatography is described. A novel method of derivative formation has been utilized allowing for methylation of the catecholamine metabolites directly in the flash-heater of the Chromatograph. The urinary excretion of HVA and VMA in 25 normal subjects gave mean values of 4.1 ±1.8 mg/24 h and 3.4 ± 1.6 mg/24 h. respectively. This procedure allows for a single technician to carry out 10 determinations in 3 h.