食品接触材料及物质仪器检验概述

目的通过对食品接触材料和物质检验的概括,寻找未来检验发展的方向。方法对食品接触检验的内容和方法进行总结。结果现代分析仪器的使用,为食品接触检验提供了很好的平台和技术。结论我国已具备初步的检验研究和标准体系,但仍需不断发展和完善。     

生化自动分析仪测定超氧化物歧化酶的方法

超氧化物歧化酶(SOD)能特异的清除超氧自由基(O_2~-)的损害作用,从而对机体生产防护,抗衰老、抗炎、抗肿瘤、抗辐射、抗自身免疫性疾病、抗氧中毒等作用。它在一些疾病的诊断和研究中是一个很重要的指标。为了适应临床检验的需要和生化自动分析仪的开发使用,特建立此方法,同时研制了试剂盒,可供自动分析仪和分光光度计使用。 1 方法该方法原理是以邻苯三酚在碱性条件下能自氧化生成有色的中间产物超氧自由     

氯分析仪测定氯化钠含量的方法验证

目的 验证CL925型氯分析仪测定氯化钠含量的方法.方法 进行线性试验、精密度试验、准确性试验及专属性试验比较仪器法和法定方法测定氯化钠含量的结果.结果 线性关系良好,决定系数为0.9999,精密度好,平均回收率为100.4％.两种方法测得的氯化钠含量结果的差异无统计学意义(t =0.515,P=0.5).结论 CL9...     

口腔溃疡膜有效成分提取方法的考察及含量测定

目的 考察不同溶剂对口腔溃疡膜中有效成分地塞米松磷酸钠和克霉唑的提取率,优化有效成分含量测定方法。方法 采用不同提取溶剂(甲醇、水、70%甲醇)对口腔溃疡膜中的有效成分进行提取,用HPLC法进行含量测定,得到最佳提取方法。结果 纯水对口腔溃疡膜中地塞米松磷酸钠和克霉唑有最好的提取效果。地塞米松磷酸钠在0.482~16.328 μg/ml范围内呈良好的线性关系(r=0.999 9),平均回收率为（103.97±1.02）%;克霉唑在5.014 5~200.580 0 μg/ml范围内呈良好的线性关系（r=0.999 8）,平均回收率为（104.23±0.63）%。结论 本研究建立的纯水提取方法操作简单,提取效率高,含量测定方法操作简便,准确性、重复性好。     

卡托普利与谷胱甘肽清除氧自由基的比较研究

用化学发光方法比较研究了卡托普利（Ｃａｐ）和谷胱甘肽（ＧＳＨ）抗氧自由基的作用。结果表明，Ｃａｐ和ＧＳＨ都具有相似的基本结构一取代的Ｎ－羧甲基－β－巯基丙酰胺。两者对黄嘌呤－黄嘌呤氧化酶体系以及碱性连苯三酚自氧化体系产生的都有清除作用并具量效关系．Ｃａｐ比ＧＳＨ的清除作用大。两者对Ｈ２Ｏ２的清除作用的量效关系曲线十分相似。结果提示．Ｃａｐ具有ＧＳＨ相似的抗氧自由基作用．并且有取代的Ｎ－羧甲基－β－巯基丙酰胺这种结构特征的化合物，也可能具有ＧＳＨ样的作用。     

黄芪薏米玉竹微粉粒度测定的方法研究

目的:建立黄芪、薏米、玉竹微粉的粒度测定的方法。方法采用Winner99显微颗粒图象分析仪对黄芪、薏米、玉竹微粉的粒度及其粒度大小分布程度进行测定。结果Winner99显微颗粒图象分析仪测定黄芪、薏米、玉竹微粉可行。     

11种保健口服液对氧自由基清除作用的研究

本文采用化学发光分析法研究了11种保健口服液清除H_2O_2或清除用酶体系及非酶体系产生的O_2~-的作用。结果表明11种保健口服液对H_2O_2和O_2~-都有不同程度的清除作用。     

黑果枸杞的抗氧化成分分析及抗氧化能力测定

目的:建立黑果枸杞抗氧化成分(花色苷、原花青素、总多酚)的检测方法,以及测定黑果枸杞的抗氧化能力。方法:本实验采用分光光度法对黑果枸杞进行了抗氧化成分含量测定。结果:花色苷的含量是0.61 g/100 g,原花青素的含量是1.6 g/100 g,总多酚的含量是4.01 g/100 g,同时对黑果枸杞进行了抗氧化能力指数(ORAC)测定,抗氧化能力为587μmoleTE/g。结论:该方法稳定快速,为黑果枸杞的开发和利用提高了理论基础。     

仪器法与镜检法检测尿液有形成分的结果分析

目的:对仪器法和镜检法的尿液有形成分检测结果进行对比,分析可能影响结果的因素,减少不必要的检测误差,保证检测结果的准确性、可靠性。方法:选取1 000例儿科住院患者的尿液样本,分别采用AX-4030尿干化学分析仪、UF-1000i尿沉渣分析仪和光学显微镜进行尿液有形成分分析。结果:在红细胞和白细胞阳性检出率方面,AX-4030与镜检法存在差异,UF-1000i和镜检法比较差异无统计学意义。UF-1000i和镜检法对管型的阳性检出率存在差异。结论:影响仪器法检测结果的因素很多,当尿干化学仪和尿沉渣分析仪检测结果不一致时,必须按照相应的方法进行镜检。     

食品样品经微波消解后同时测定砷、铅、铜的方法研究

应用CEM公司的MARS-5型密闭微波消解系统,对食品样品进行消解,消解过的样品可用原子吸收和原子荧光光度计同时测定其中的铅、砷、铜。此方法的特点是减少环境污染,节省时间、操作简单、快速、结果准确、灵敏度高。     

Trimetazidine: stability indicating RPLC assay method

An accurate, specific and reproducible reversed phase liquid chromatographic method for the determination of trimetazidine hydrochloride in presence of its degradation products is reported. The mobile phase consisted of water-acetonitrile-triethylamine (90:10:0.1, v/v/v) adjusted with o-phosphoric acid to a pH of 3.3. Chromatography was performed using C-18 column at a flow rate of 1.0 ml/min and the drug along with its degraded products was detected at 270 nm. The calibration curve of trimetazidine hydrochloride in methanol was linear in the range 500-3000 ng. The mean value of correlation coefficient, slope and intercept were 0.99859 &# 0.001, 17.7986 &# 0.0709 and 482.56 &# 147.03, respectively. The limits of detection and quantitation were 5 and 20 ng, respectively. The recovery of trimetazidine hydrochloride was about 99-100%. This method was utilized to analyze trimetazidine hydrochloride from conventional tablets and controlled release pellets in the presence of commonly used excipients.     

Improved sensitivity of digoxin assay by modification of the EMIT 2000 method

A modified EMIT 2000 digoxin assay was developed on the Cobas Mira plus analyzer for the determination of very low plasma concentrations of the drug. The major modifications were a higher plasma volume withdrawn during the analysis step and calibration curves constructed in the range 0-2 ng/ml using calibrators made up with biological matrix. Assays were controlled with an internal, four-level quality control (targets: 0.15; 0.60; 1.70; 2.70 ng/mL). The within-day and day-to-day mean observed values +/- SD (n = 10) of these quality controls were 0.14 +/- 0.02 and 0.15 +/- 0.02 ng/mL; 0.57 +/- 0.01 and 0.64 +/- 0.03 ng/mL; 1.55 +/- 0.06 and 1.62 +/- 0.04 ng/mL, 2.82 +/- 0.09 and 2.82 +/- 0.12 ng/mL, respectively. The detection and the quantification limits were 0.02 and 0.08 ng/mL, respectively. No significant difference was observed between digoxin plasma concentrations measured by the original and the modified EMIT 2000 digoxin assay in 25 plasma specimens, ranging from 0.4 to 3.0 ng/mL, from patients receiving the drug. This modified digoxin EMIT 2000 assay was subsequently used to study digoxin pharmacokinetics after each of 18 healthy volunteers was administered a single 0.5 mg oral dose. The pharmacokinetic parameters found in this study were in accordance with the literature in healthy subjects, using radioimmunoassay (RIA) for digoxin plasma concentration determinations. In conclusion, the lower limit of quantification of this modified EMIT 2000 digoxin assay is similar to that of RIA and can serve as a valuable screen for digoxin pharmacokinetic interactions studies.     

异硫氰酸苯甲酰酯稳定性指示性气相分析方法开发和验证

目的:建立异硫氰酸苯甲酰酯稳定性指示性气相分析方法.方法:气相色谱柱DB-1(30m×0.25mm×0.25μm);载气:氦气;检测器:氢焰离子化检测器;起始柱温为100℃,维持1.3min,每分钟15℃的速率升温至200℃,然后以每分钟5℃的速率升温至240℃,再以每分钟10℃的速率升温至300℃,维持6min;进样口温度:200℃;检测器温度:300℃;柱流量:1.0mUmin;进样量:1μL.结果:专属性、线性、定量限、检测限、精密度、溶液稳定性、准确度经验证,结果均良好.结论:本法可用于异硫氰酸苯甲酰酯的初步稳定性研究.     

亚胺培南血药浓度测定方法改进及其在血浆中稳定性考察

目的:建立高效液相色谱法测定人血浆中亚胺培南浓度,并重点考察亚胺培南血浆样品的稳定性。方法:采用Venusil XBP C₁₈ (5μm,4.6mm×250 mm)色谱柱,以10 mmol·L^-1磷酸二氢钾-含四丁基溴化铵(0.3 mmol·L^-1)甲醇液(96:4,V:V)为流动相,调节pH至7.2,柱温为30℃,内标为5-羟基吲哚-3-醋酸,检测波长300 nm。稳定剂0.5mol·L^-1 3-吗啉丙磺酸缓冲液(pH6.8)-乙二醇-水,体积比2:1:1。结果:低、中、高3个浓度提取回收率分别为(89.6±1.7)%,(93.9±2.2)%,(91.4±0.4)%,批内、批间RSD均小于15%;血浆中亚胺培南在0.1~100 μg·ml^-1浓度范围内线性关系良好(r=0.995~0.996),定量下限为0.1μg·ml^-1;不加稳定剂时,含亚胺培南的血浆样品在室温、4℃、-30℃条件下分别可以稳定2,6,8 h,加入稳定剂后分别为6,12,48 h。结论:本试验建立的分析方法线性范围宽,操作简便,准确度高,可用于亚胺培南血药浓度的测定,适用于重症感染患者治疗药物监测。     

Establishment of inherent stability of stavudine and development of a validated stability-indicating HPLC assay method

The present study describes degradation of stavudine under different stress conditions (hydrolysis, oxidation, photolysis and thermal stress), and establishment of a stability-indicating reversed-phase HPLC assay method. The drug was found to hydrolyse in acidic, neutral and alkaline conditions and also under oxidative stress. The major degradation product formed under various conditions was thymine, as evidenced through comparison with the standard and spectral studies (NMR, IR and MS) on the isolated product. Separation of drug, thymine and another minor degradation product was successfully achieved on a C-18 column utilising water–methanol in the ratio of 90:10. The detection wavelength was 265 nm. The method was validated with respect to linearity, precision (including intermediate precision), accuracy and specificity. The response was linear in the drug concentration range of 25–500 μg ml⁻¹. The mean values (±R.S.D.) of slope and correlation coefficient were 24256 (±0.679) and 0.9994 (±0.0265), respectively. The R.S.D. values for intra- and inter-day precision studies were <0.210 and <1%, respectively. The recovery of the drug ranged between 99.7 and 101.5% from a mixture of degraded samples. The method even proved to be affective on application to a stressed marketed capsule formulation.     

Guanabenz degradation products and stability assay.

Guanabenz, [(2,6-dichlorobenzylidene)amino]guanidine, acetate was shown to be the E-isomer. It decomposed to form the Z-isomer, 2,6-dichlorobenzaldehyde, aminoguanidine, and 2,6-dichlorobenzaldehyde semicarbazone. A stability-indicating assay for the intact drug in the presence of all of its decomposition products by the use of UV spectroscopy is presented.     

Best practices during bioanalytical method validation for the characterization of assay reagents and the evaluation of analyte stability in assay standards, quality controls, and study samples

Characterization of the stability of analytes in biological samples collected during clinical studies together with that of critical assay reagents, including analyte stock solutions, is recognized as an important component of bioanalytical assay validation. Deficiencies in these areas often come to light during regulatory inspections. Best practices, based on current regulatory guidance, for the assessment of these issues as they pertain to ligand binding and chromatographic assays are covered in this review. Additionally, consensus recommendations reached during the recent AAPS/FDA Workshop on bioanalytical assay validation are highlighted.