高效液相色谱法测定保健药品中的褪黑激素

用ＨＰＬＣ测定具有改善睡眠等特定功能的保健药品“梦通宁”中的褪黑激素,并结合紫外光谱来鉴定样品中的褪黑激素。以Ｎｏｖａｐａｋ Ｃ１８柱为分离柱,Ｖ（甲醇）：Ｖ（０．０５ｍｏｌ／Ｌ的Ｎａ２ＨＰＯ４）＝３０：７０作流动相,检测波长为２３０ｎｍ,用外标法进行定量分析,方法回收率９８,１１％,检出限为０．５ｍｇ／Ｌ。     

纳米银刻蚀比色法检测褪黑激素

该文构建了一种基于氯金酸刻蚀球形纳米银检测褪黑激素的简单、高灵敏比色探针。纳米银可被氯金酸氧化刻蚀为Ag+,同时还原生成的纳米金沉积在刻蚀后的纳米银表面,导致其溶液的吸光度降低和颜色增强(由黄色变为橘黄色)。当向体系中加入褪黑激素时,氯金酸被还原,抑制了纳米银的刻蚀,从而使得溶液吸光度增加和颜色变浅。结果显示,在0.1 nmol/L~1.0 mmol/L范围内,褪黑激素浓度对数值(lgC)与其吸光度改变值(ΔA)呈良好的线性关系,线性方程为ΔA=0.049 8+0.516lgC,相关系数(R2)为0.996 4,检出限为0.09 nmol/L。该方法成功应用于人体尿液和葡萄中的褪黑激素的测定。     

反相HPLC法测定舒心口服液中阿魏酸含量

本文报道了以反相ＨＰＬＣ法测定舒心口服液中阿魏酸含量的方法。试样酸化反经乙酸乙脂萃取，甲醇定容，用Ｓｐｈｅｒｉ ＰＲ－１８ ５－Ｍｉｃｒｏｎ柱，甲醇－５％乙酸水溶液作流动相，检测波长为３２２ｎｍ，线性范围０－１４．４８μｇ／ｍＬ，平均回收率为９６．７０％。该法简便，灵敏，准确，适合药品生产中的质量控制。     

反相PHLC法测定舒心口服液中阿魏酸含量

本文报道了以反相ＨＰＬＣ法测定舒心口服液中阿魏酸含量的方法。试样酸化后经乙酸乙脂萃取，甲醇定容，用ＳｐｈｅｒｉＰＲ－１８５－Ｍｉｃｒｏｎ柱，甲醇－５％乙酸水溶液（２３：７７）作流动相，检测波长为３２２ｎｍ，线性范围０～１４．４８ｇ／ｍＬ，平均回收率为９６．７０％。该法简便，灵敏，准确，适合药品生产中的质量控制。     

高效液相色谱法同时测定食品和药品中的糖及其降解产物5—羟甲基糠醛

５－羟甲基糠醛（５－ＨＭＦ）是糖的降解产物，本文提出了用高效液相色谱法同时测定食品和药品中的蔗糖，葡萄糖，果糖和５－ＨＭＦ的方法，采用氢型阳离子交换色谱法Ａｍｉｎｅｘ－ＨＰＸ－８７Ｈ，以乙腈－０．０１ｍｏｌ／Ｌ，硫酸（４０：６０）为流动相分离糖和５－ＨＭＦ，使用串联的紫外光度检测器（２８０ｎｍ）和示差折光检测器，分别检测５－ＨＭＦ和糖。     

褪黑激素的合成

以5－甲氧基吲哚为起始原料，经4步反应合成了褪黑激素（MLT).5－甲氧基吲哚和草酰氯在0℃-5℃定量反应生成5－甲氧基吲哚－3－草酰氯（I），I直接用氨水胺化得98％的5－甲氧基吲哚－3－草酰胺（Ⅱ），Ⅱ用氢化铝锂还原得到5－甲氧基色胺（Ⅲ），收率57％，Ⅲ经乙酰化即得目标产物MLT，收率80％。     

新型褪黑激素衍生物的合成及其抗氧化活性

以褪黑激素和取代苄溴为原料,四氢呋喃为溶剂,经亲核取代反应在N1位衍生化,合成了16个褪黑激素衍生物(3a~3p);以褪黑激素和取代苯硼酸为原料、四三苯基膦钯作为催化剂、甲苯和乙醇作为溶剂,加热回流下发生Suzuki偶联反应在C2位衍生化,合成了11个褪黑激素衍生物(7a~7k)。所有产物的结构经1H NMR、 13C NMR和LC-MS表征,其中有15个为新化合物(3a~3o)。体外抗氧化活性(ORAC法)测试结果显示：抗氧化活性最强的为7a,是阳性对照L-抗坏血酸(VC)的1.68倍[μMTE/gDW=7582.0(7a),μMTE/gDW=4507.9(VC)]。     

液相色谱-质谱联用在线测定3种植物激素

褪黑激素、复合胺及吲哚乙酸等神经递质在高等植物中的发现为理解植物生理的机制提供了新的可能性.建立了一种在线制备方法,将样品粉末化后装填入小柱,利用水、甲酸-水和甲醇-水在线预洗制备后,切换至分析流路,采用梯度洗脱及ESI源LC-MS/MS检测植物中3种神经递质,每个样品的检测时间10 min,较离线方法的分析时间缩短了...     

固相萃取/超高效液相色谱－串联质谱法同时测定水产养殖“非药品”投入品中37种禁限兽药

建立了固相萃取/超高效液相色谱－串联质谱（SPE/UPLC－MS/MS）同时测定水产养殖“非药品”投入品中37种禁限兽药（磺胺类、酰胺醇类、硝基咪唑类、苯并咪唑类、抗病毒类）残留量的分析方法。样品经含0.2%甲酸的80%乙腈水溶液提取,Mcllvaine－乙二胺四乙酸二钠（Mcllvaine－Na2EDTA）缓冲液螯合,超声波萃取,Waters PRiME－HLB固相萃取柱净化,通过C18色谱柱分离,采用UPLC－MS/MS选择电喷雾ESI离子源在正、负离子多反应监测模式下分析测定,基质添加标准曲线外标法定量。37种禁限兽药标准曲线的相关系数均不低于0.991,检出限为0.156 ~ 1.94 μg/kg,定量下限为0.520 ~ 6.47 μg/kg,加标回收率为71.6% ~ 119%,相对标准偏差为1.2% ~ 15%。该方法快速、准确、灵敏度高,可应用于水产养殖“非药品”投入品中37种禁限兽药残留的快速准确筛查和检测。     

用荧光素和碘测定抗坏血酸的研究

研究出了一种简单而灵敏的应用荧光素作为荧光剂测定抗坏血酸的方法。方法是在pH为7．20条件下抗坏血酸抑制荧光素与碘的反应,测定的线性范围为50－300ng/mL,检测限为21．5ng/mL,用于饮料和药品中抗坏血酸的测定,取得满意的结果。     

Micellar electrokinetic capillary chromatography for fast separation and sensitive determination of melatonin and related indoleamines using end-column amperometric detection

MEKC was used in conjunction with end-column amperometric detection (AD) at a carbon disc electrode (0.3 mm diameter) for the selective and sensitive determination of melatonin and its five related indoleamines including its precursors and metabolites in the pineal gland. The introduction of a sample stacking technique in injection and the buffer additive SDS in the buffer solution system provided the rapid and sensitive analysis. Optimal buffer conditions (10 mmol/L phosphate containing 20 mmol/L SDS, pH 7.2), detection potential (+1.0 V vs. Ag/AgCl), and electrokinetic injection 10 s with the separation voltage of 24 kV were employed to achieve the baseline separation of six pineal hormones within 15 min. The peak currents and the analyte concentrations have a good linear relationship over the range of 6.0 x 10(-8) 6.0 x 10(-5 )mol/L. The detection limits for six pineal hormones by AD are 9.7 to 41.8 nmol/L (equal to 2.0 to 9.7 ng/mL) (S/N = 3), respectively. It is proved to provide about 30- to 250-fold improvement over UV, and be comparable with the sensitive fluorescence detection, which needs pre-column derivatization. The proposed method has been applied for analysis of melatonin and related indoleamines in rat pineal glands. A very simple sample pretreatment procedure, merely involving the homogenization step in perchloric acid, was enough to achieve recoveries in the range of 71 to 127% for all the analytes in the pineal gland.     

Determination of Melatonin Hormone in Bulk Form,Tablets and Human Serum by Square‐Wave Cathodic Adsorptive Stripping Voltammetry

Melatonin hormone plays an important role in many distinct physiological functions. A fully validated, sensitive and reproducible square‐wave cathodic adsorptive stripping voltammetric procedure was described for determination of melatonin in bulk form, tablets and human serum. The procedure was based on the reduction of the adsorptive hormone onto a hanging mercury drop electrode. Reduction behavior of melatonin was studied in both Britton‐Robinson (pH 2–11) and acetate (4.5–5.5) buffers. Acetate buffer of pH 5.0 was found reasonable as a supporting electrolyte for assay of the drug. The square‐wave cathodic adsorptive stripping voltammogram of melatonin showed a single well‐defined peak at ?1.45 V (vs. Ag/AgCl/KCl_s) using an accumulation potential of ?0.65 V. This peak may be attributed to the reduction of C?O double bond of the amide functional group of the reactant molecule. A mean recovery for 1×10^?8 M melatonin in bulk form followed 30 s accumulation of 98.87%±0.78 and a detection limit of 3.13×10^?10 M were achieved. The proposed procedure was successfully applied for the determination of the drug in tablets and human serum with mean recoveries of 97.68%±0.57 and 101.67%±0.85, respectively. A detection limit of 8.80×10^?10 M was achieved for the determination of the drug in human serum. Results of the proposed method were comparable and coincided with those obtained by reported method. Vitamin B₆ and common excipients, which are co‐formulated with melatonin, did not interfere. Also the effect of some interfering compounds such as serotonin, tryptophan and 5‐hydroxytryptophan on the determination of melatonin in human serum was studied, and all have no significant effect on the assay recovery.     

End-column amperometric detection of melatonin by high performance capillary electrophoresis

A rapid and sensitive method is described for the detection of melatonin in rat pineal gland and melatonin tablets. Capillary electrophoresis (CE) with electrochemical detection (EC) was used. This method had high sensitivity and good reproducibility. The detection limit of melatonin was as low as 1.3x10(-9) mol/l (0.30 fg). There was a linear range of concentration from 3.9x10(-7) to 3.25x10(-5) mol/l with a correlation coefficient of 0.999. The linear equation was Y=8.27+0.0042X with a slope of 0.0042 pA/nM. The relative standard deviations of the peak current response and the migration time for 16 continuous injections of 6.5 muM melatonin were 4.5 and 0.48%, respectively. The proposed method was applied to detect melatonin in the rat pineal gland and the melatonin tablets. Good results were obtained compared with previous reports.     

A Simple Method for Melatonin Determination in the Presence of High Levels of Tryptophan using an Unmodified Carbon Paste Electrode and Square Wave Anodic Stripping Voltammetry

Electrochemical determination of melatonin in the presence of tryptophan is a challenge because of the coincidence of voltammetric signals of these compounds when executing a voltammetric technique. The new method for selective determination of melatonin based on the square wave anodic stripping voltammetry determination of an electroactive product of melatonin was suggested here. This product is produced by previously applied positive pre-potential to a carbon paste electrode, immersed in the test solution. By this means, the electrochemical signal of melatonin was separated effectively from that of tryptophan, making it possible to determine melatonin in the presence of a high concentration of tryptophan. The effect of important parameters on electrode performance was studied and optimized. The optimum response was obtained at pH=2 and utilizing the pre-potential magnitude of +0.8 V, applied for 10 s. A linear relationship was found between peak current intensity and melatonin concentrations over the range of 5.00×10⁻⁷ to 8.00×10⁻⁵ mol L⁻¹. A detection limit of 8.30×10⁻⁸ mol L⁻¹ was calculated for the method (S/N=3). The selectivity of the method was considerably high, because of the independence of melatonin signal to the presence of higher amounts of some potentially interfering agents such as ascorbic acid, tryptophane glucose, etc. As an analytical application, the proposed sensor was used for the determination of melatonin in pharmaceutical and food samples.     

高效液相色谱法同时测定牛肉及其制品中敌草隆、绿麦隆的残留量

介绍了用高效液相色谱同时测定牛肉及其制品中脲类除草剂——敌草隆、绿麦隆残留量的方法。色谱柱为ＳｅｌｅｃｔｏｓｉｌＣ１８柱,流动相为甲醇－水（６０∶４０,Ｖ／Ｖ）,ＵＶ－２４５ｎｍ检测。最小检测量：敌草隆为０．４ｎｇ,绿麦隆为０．５ｎｇ。线性范围均为０．０５～１０ｍｇ／Ｌ。回收率：敌草隆为８７．３４％～８７．６４％,绿麦隆为８８．７８％～９１．９４％。     

Determination of serotonin, melatonin and metabolites in gastrointestinal tissue using high-performance liquid chromatography with electrochemical detection

In this paper we show a simple isocratic chromatographic method for the detection of serotonin and its precursors and metabolites from various types of gastrointestinal tissue. The paper measures for the first time basal measurements of melatonin in the gastrointestinal tract, which has recently been shown to be released from the musosal lining of the gut. Tissue samples were stable following sample preparation in either 0.1 m perchloric acid or mobile phase. Analysis was carried out using a mobile phase consisting of 10% acetonitrile-90% acetate acid buffer pH 4.0 with 2 mm decane-sulfonic acid sodium salt at a column temperature of 50 degrees C. Electrochemical detection was utilized at a potential of +850 mV vs Ag/AgCl reference electrode at 10 microA full-scale deflection. The detection limit of 5-HT and melatonin was 241 and 308 nm respectively for a 10 microL injection. As a result of the method optimization, total analysis was reduced to 30 min. Accurate responses of the tissue samples following sample preparation could be obtained following a week after storage at -80 degrees C. This method is capable of preparing and analysing of samples from all regions of the gastrointestinal tract.     

高效液相色谱法测定皮炎宁酊中间苯二酚和水杨酸的含量

采用高效液相色谱法测定了皮炎宁酊中间苯二酚和水杨酸的含量。色谱柱为ＨｙｐｅｒｓｉｌＯＤＳ柱,流动相为Ｖ（甲醇）∶Ｖ（水）∶Ｖ（乙酸）＝５０∶５０∶０．９。检测波长为２８５ｎｍ。在此条件下,间苯二酚和水杨酸可与其降解产物及杂质完全分开。     

固相萃取富集高效液相色谱法测定苯氧乙酸和2,4-二氯苯氧乙酸

建立了以固相萃取技术进行富集 ,高效液相色谱法进行分离和检测苯氧乙酸和 2 ,4 二氯苯氧乙酸的方法。环境水中的苯氧乙酸和 2 ,4 二氯苯氧乙酸用Sep PakC18Cartridge进行固相萃取。液相色谱的条件是 :Shim PackCLCODS柱为分析柱 ;甲醇 水 (9∶1,V/V)为流动相 ;流速为 1mL/min ;在UV 2 75nm波长下进行检测。本法具有良好的灵敏度和重现性     

Comparison of analytical methods for the quality control of a new formulation containing soy extract and melatonin

Three analytical methods have been developed and compared for the quality control of a new formulation (Soymen GN(R) capsules) containing soy extract and melatonin for the treatment of menopausal symptoms. The first method is based on MEKC with diode-array detection, using a mixture of basic carbonate buffer (95%) and methanol (5%), containing 55 mM SDS, as the BGE. The second method is an HPLC method with UV detection at 260 nm. The third method is an HPLC method coupled to amperometric detection which is carried out at an oxidation potential of +0.8 V. In both HPLC systems, the chromatographic separation is obtained on an RP C18 column using a mixture of ACN and an acidic phosphate buffer (25:75 v/v) as the mobile phase. A feasible pretreatment procedure with a methanol/water mixture has been implemented to achieve the quantitative extraction of the main soy isoflavones and of melatonin from the capsules. The results obtained with the three methods are in good agreement with each other and satisfactory in terms of linearity (r(2) >0.9996), precision (RSD <5.4%) and accuracy (recovery >97%). Thus, each of the three analytical methods seems to be suitable for the simultaneous analysis of the main soy isoflavones and melatonin in the new commercial formulation.     

液相色谱/蒸发光散射测定转基因烟草提取液中的海藻糖

 采用乙二胺动态修饰硅胶柱分离、蒸发光散射检测器测定了转基因烟草提取液中的糖。 4种糖的峰面积标准曲线在 10 0mg/L～ 15 0 0mg/L范围内均具有良好的线性关系。所建立的方法对果糖、葡萄糖、蔗糖、海藻糖的检测下限分别为 10mg/L ,2 0mg/L ,10mg/L和 10mg/L。