人工神经网络紫外分光光度法同时测定去痛片组分含量

用BP人神经网络处理复方制剂去痛片的紫外吸收光谱数据,达到了对其各组分含量进行同时测定的目的。通过对网络结构和参数的优化,提高了预报的准确度。     

紫外分光光度法测定富马酸二甲酯的含量

本文研究了用紫外分光光度法测定富马酸二甲酯含量的方法 ,探讨了测定过程中有关条件的变化对测定的影响 ,获得了测定的适宜条件 :波长 2 1 0± 2nm ;温度 1 9～ 2 5℃ ;无水乙醇为溶剂 ;测定体系的pH为7.2 5～ 8.2 5。DMF的含量与溶液的吸光度的关系为P =0 .0 933A +0 .0 4 1 6,经与色 -质谱分析结果对比表明本法具有较高的准确性     

紫外分光光度法测定中草药中铁的含量

对白芍、党参、白术、茵陈、天冬、枸杞子、当归、菟丝子、金银花、桔梗中微量元素铁的含量进行了测定,为进一步研究其药理作用提供基础。中草药消化后配制成溶液,用邻二氮菲作显色剂,使用UV-1200型紫外分光光度计在510 nm处测定各样品的吸光度(A),求出样品中微量元素铁的含量。结果显示,当归和金银花中铁的含量较丰富,分别为(135.367 8±0.111 1)μg/g和(125.936 4±0.159 9)μg/g;桔梗含铁量最少,为(3.510 9±0.159 9)μg/g,10种中草药中铁含量有显著性差异(P<0.05)。结果为使用中草药治疗系统疾病提供了可靠数据,10种中草药在用量范围内Fe含量适合人体每天正常摄入量。     

紫外分光光度法测定花生壳中总黄酮的含量

从花生壳中提取总黄酮物质,并用紫外分光光度法对其进行测定。建立了一种以无水乙醇为溶剂,检测波长为359nm的测定花生壳总黄酮含量的新方法。结果表明,总黄酮含量在0.005～0.025mg/mL范围内与吸光度线性关系良好,相关系数r=0.9995,平均加标回收率为98.5%,测定结果的相对标准偏差为2.1%(n=5)。该法适用于花生壳总黄酮的定量测定。     

紫外分光光度法测定富马酸含量的新方法

研究了紫外分光光度法测定富马酸含量的新方法.在乙醇溶液中,富马酸最大吸收在210.5 nm处,表观摩尔吸光系数为ε210.5=1.05× 104L·mol-1·cm-1.方法的检出限为0.1μg/mL,此法具有灵敏度高、操作简便、快速等优点.     

紫外分光光度法测定白芍中重金属的研究

用紫外分光光度法测定了白芍中重金属含量。结果表明,杭白芍重金属含量(甜)为15．43μg/g,亳白芍为18．47μg/g。该法简便、快速、重现性好,适用于中药材实际生长中重金属的检测。     

紫外分光光度法测定黄芩中黄芩苷的含量

从黄芩中提取黄芩苷,并用紫外分光光度法对纯化后的黄芩苷进行测定。建立了一种以乙醇为溶剂、超声溶解制样、检测波长为278nm的测定黄芩苷含量的新方法。纯化后黄芩苷纯度达98．76％,黄芩苷乙醇溶液的含量在1～18μg／mL之间与吸光度呈良好的线性关系,相关系数为0．9993,平均回收率为99．49％,相对标准偏差为0．328％（n=4）。该方法适用于黄芩苷的定量测定。     

紫外分光光度法测定丙酮酸

基于丙酮酸在紫外吸收光谱290～340nm区有较强的吸收,建立了分光光度法测定丙酮酸(盐)的方法。在pH11．0的水溶液中,位于320nm处,丙酮酸有吸收,而其他有机酸和杂质无吸收或吸收不明显。在320nm处,丙酮酸在0．2～2．8g／L范围内符合比耳定律,其R2为0．9997,平均回收率99．8％,RSD0．46％。该法适合于发酵液和分离提取过程中丙酮酸及其盐类的测定。     

紫外分光光度法测定蔬菜鲜样中的硝酸盐

建立了紫外分光光度法测定蔬菜鲜样中硝酸盐含量的方法，经t检验证明，该方法的测定结果与酚二磺酸法无显著性差异，RSD小于4．5％，方法操作简便，适用于蔬菜中硝酸盐含量的测定。     

紫外分光光度法检测水中微量溴酸盐的含量

基于BrO3-与I-在酸性介质中发生氧化还原反应形成具有紫外吸收的I3-的性质,采用了紫外分光光度法测定水体中微量溴酸盐含量,方法加标回收率在98%～102%之间,相对标准偏差RSD为1.7%,线性相关系数为0.9991,检测限为4.0μg/L,能满足现有标准的检测要求。     

气相毛细管柱切割-反吹技术及归一化法分析汽油中的芳烃(英文)

 发展了一种采用毛细管气相柱切割 反吹技术分析汽油中芳烃的方法。利用强极性毛细管预柱将芳烃保留至n C10 的脂肪族化合物之后 ,并将其反吹到非极性毛细管柱中按沸点详细分离分析。该方法使预柱先流出的组分和分析柱流出的组分通过一个微型三通进入同一检测器中 ,因此可用归一化方法定量分析汽油中的芳烃。该方法可在 15min内完成汽油中苯至C10 芳烃的分析 ,结果的相对标准偏差 (RSD)≤ 3% ,切割误差为± 5s时分析结果的RSD≤ 4 %。     

比导数荧光光谱法测定混合芳烃

比值导数荧光光谱法是将混合物的光谱除以其中一组分的光谱得到比值光谱，利用比值光谱对波长求导所得到的比值导数光谱来达到消除干扰组分影响、分辨重叠光谱的目的。作者研究用比值导数荧光光谱法对２组分和３组分荧光光谱严重重叠的菲、、蒽混合芳烃溶液进行分析，测试效果良好，回收率为９４％～１０５％。     

Determination of Polycyclic Aromatic Hydrocarbons in Camellia Oil by Gel Permeation and High-Performance Liquid Chromatography

A rapid method for the quantification of polycyclic aromatic hydrocarbons in camellia oil is reported. The analytes were extracted from camellia oil using 1:1 (v/v) cyclohexane/ethyl acetate, isolated by gel permeation chromatography, and determined by high-performance liquid chromatography with fluorescence detection. The method features good sensitivity, as the limits of quantification were from 0.33 to 0.67 microgram per kilogram, which are lower than those of regulatory maximum residue limits. Intra- and inter-day precision ranged from 1.19 to 4.52 percent and 1.86 to 3.56 percent, respectively. The recoveries were 79.3–87.9, 85.3–93.4, and 89.6–97.3 percent at fortified levels of 10, 25, and 50 microgram per kilogram, respectively. Moreover, the method is rapid, requiring less than three hours, in comparison to traditional approaches, which require more than twenty-four hours. The developed method was also inexpensive in terms of solvent use and employed to determine polycyclic aromatic hydrocarbons in five camellia oil products. High concentrations of acenaphthene, benz[a]anthracene, benzo[b]fluoranthene, benzo[k]fluoranthene, and benzo[a]pyrene were present in samples produced through extrusion and high temperature pressing. The results suggest that camellia oil processing should be monitored to minimize the presence of polycyclic aromatic hydrocarbons.     

多环芳烃的超临界流体色谱分离研究

烃中多环芳烃（晕苯和卵苯）的分离是极其困难的。研究了在不同极性毛细管填充ＳＦＣ柱上多环芳烃的分离条件。选用国产１５０ｍｍＣＮ填充柱,ＣＯ＿２为流动相,线性升压,ＦＩＤ检测,可在２６ｍｉｎ内将烃中三到十环多环芳烃分离,定量重复性良好。     

Resolution of Polynuclear Aromatic Hydrocarbons by Packed Column GLC

Abstract

Specific GLC stationary phases have been identified which allow the resolution of certain polynuclear aromatic hydrocarbon (PAH) isomers with packed six foot columns. Phenanthrene and benz(a)anthracene can be measured in the PAH fraction of tobacco smoke condensate without significant interferences from anthracene and chrysene, respectively.     

柱层析-高效液相色谱测定煤沥青中16种多环芳烃

建立了高效液相色谱测定煤沥青甲苯抽提液中16种美国环境保护署(EPA)重点监控多环芳烃(PAHs)含量的方法。以Agilent PAHs色谱柱为分离柱,不同比例混合的乙腈和水作流动相进行梯度洗脱,紫外检测器检测,16种PAHs的线性范围为0.5~20 mg/L,相对标准偏差小于2%,加标回收率为83.7%~98.9%。对两种不同来源的煤沥青进行分析,结果显示,两种煤沥青中16种PAHs的含量分别为107.89 g/kg和103.04 g/kg,其中苯并[a]芘含量分别为11.86 g/kg和13.85 g/kg。该方法可用于不同种煤沥青中致癌性PAHs的准确测定。     

Determination of Polycyclic Aromatic Hydrocarbons in Traditional Chinese Medicine Raw Material,Extracts, and Health Food Products

The four polycyclic aromatic hydrocarbon markers (PAH4) of benzo[a]anthracene (BaA), chrysene (Chr), benzo[b]fluoranthene (BbF), and benzo[a]pyrene (BaP) are indicators showing polycyclic aromatic hydrocarbon (PAH) contamination levels in Chinese medicine raw materials (CMRMs), extracts and health food products; Samples of herbal medicine, herbal extracts, and food supplements were extracted with n-hexane, then cleaned up sequentially on Florisil and EUPAH solid-phase extraction (SPE) columns. A gas chromatography–mass spectrometry method for the determination of four polycyclic aromatic hydrocarbon markers in Chinese medicine raw material, extracts, and health food products was established; In spiked-recovery experiments, the average recovery was about 78.6–107.6% with a precision of 2.3–10.5%. The limit of quantification (LOQ) and limit of detection (LOD) of the PAH4 markers in this method were 2.0 μg/kg and 0.7 μg/kg, respectively. When the developed method was utilized to determine PAH4 contents in 12 locally available health food products, 3 samples contained over 10.0 μg/kg BaP, and 5 samples contained over 50.0 μg/kg PAH4. The European Union (EU) limits for BaP and PAH4 are 10 and 50.0 μg/kg, respectively; therefore, more attention must be drawn to the exposure risk of BaP and PAH4 in CMRMs, their extracts, and health food products. According to the risk assessment based on the Margin of Exposure (MOE) method, it is recognized that the products mentioned in this study pose a low risk.     

羟基多环芳烃的电喷雾电离离子阱串联质谱检测

采用电喷雾电离离子阱串联质谱检测了1-/2-羟基萘、 2-羟基芴、 2-/3-/4-/9-羟基菲、 6-羟基屈和3-羟基苯并[a]芘等9种不同环数的羟基多环芳烃(OH-PAHs, 2~5环), 考察了碰撞诱导解离操作参数活化值Q和相对碰撞能量对羟基多环芳烃各单体碎片离子产率的影响. 通过优化活化值Q和相对碰撞能量, 得到了3-羟基苯并[a]芘的碎片离子, 提高了1-羟基萘、 2-羟基芴、 3-/9-羟基菲和6-羟基屈碎片离子的产率, 并发现活化值Q是电喷雾电离离子阱串联质谱检测不同环数PAHs的关键参数.     

高效液相色谱-荧光-紫外串联测定土壤中16种多环芳烃

采用高效液相色谱-荧光-紫外检测器串联测定土壤中16种多环芳烃。通过液相色谱柱、荧光激发和发射波长等条件的优化,实现16种多环芳烃组分基线完全分离来和15种多环芳烃荧光高灵敏度检测,并通过荧光-紫外串联检测来提高定性的准确度等。在优化的实验条件下,荧光检测器的检出限为0.015~0.8μg/L;紫外检测器检出限为0.4~30μg/L;方法精密度为0.58%~1.36%(荧光)、1.13%~5.48%(紫外);样品加标回收率为76.4%~111%。     

色谱／质谱联用技术分析测定贻贝中的多环芳烃

介绍了ＧＣ－ＭＳ联用技术－物质征离子选择法测定贻贝中多环芳烃的分析方法，并就定性定量离子的选择，以及方法的准确度和精密度进行了探讨。结果表明，本方法适用于海洋生物贻贝，牡蛎中ＰＡＨｓ的分析测定。