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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。 相似文献
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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。 相似文献
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反相HPLC法测定舒心口服液中阿魏酸含量 总被引:1,自引:0,他引:1
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。 相似文献
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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 总被引:7,自引:0,他引:7
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。 相似文献
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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)]。 相似文献
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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... 相似文献
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用荧光素和碘测定抗坏血酸的研究 总被引:4,自引:0,他引:4
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。 相似文献
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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. 相似文献
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《Electroanalysis》2003,15(13):1121-1128
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/KCls) 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. 相似文献
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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. 相似文献
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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. 相似文献
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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. 相似文献
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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 总被引:16,自引:0,他引:16
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。 相似文献
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Saracino MA Mercolini L Musenga A Bugamelli F Raggi MA 《Journal of separation science》2008,31(10):1851-1859
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. 相似文献
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液相色谱/蒸发光散射测定转基因烟草提取液中的海藻糖 总被引:6,自引:0,他引:6
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。 相似文献