盐酸二甲双胍药物中杂质测定方法研究进展

对近年来盐酸二甲双胍类药物中杂质的测定方法进行综述.盐酸二甲双胍类药物中的杂质主要有双氰胺、二甲胺以及由二甲胺形成的亚硝胺类基因毒性杂质等.测定方法主要有高效液相色谱(HPLC)法、离子色谱(IC)法、高效液相色谱–串联质谱(HPLC–MS/MS)法和气相色谱–串联质谱(GC–MS/MS)法,其中高效液相色谱法主要用于...     

LC–IT–TOF MS法分析湖南黑茶中水溶性成分

建立了湖南黑茶中水溶性成分的液相色谱–离子阱串联飞行时间质谱(LC–IT–TOF MS)快速分离和确证方法。实验用90℃热水恒温提取湖南黑茶样品中水溶性成分,采用液相色谱–离子阱串联飞行时间质谱仪对其中的水溶性提取物进行分离测定。利用准确质量数匹配和自建质谱数据库检索,结合保留时间、多级质谱、特征碎片离子等信息,对湖南黑茶中的43种水溶性化合物的进行了初步确证。该法可得到黑茶独特滋味品质的特征成分,为湖南黑茶品质评价和质量控制提供了一种新的技术手段。     

LC–MS/MS法测定动物性食品中万古霉素残留

建立液相色谱–串联质谱(LC–MS/MS)法检测动物性食品中万古霉素药物残留的方法。用磷酸盐缓冲溶液对动物性食品中的万古霉素进行提取,经HLB固相萃取柱净化,采用电喷雾离子源,以正离子检测方式进行质谱分析。实验结果表明,万古霉素质量浓度在1~500μg/L范围内与色谱峰面积呈良好的线性,相关系数r=0.998。低、中、高3个质量浓度添加水平的回收率为84.8%~118.2%,相对标准偏差为2.2%~7.2%(n=5),检出限为2μg/kg。     

CFDA发布食品补充检验方法

正不久前,国家食药总局发布《食用油脂中辣椒素的测定》食品补充检验方法。本次发布的检验方法采用高效液相色谱–串联质谱仪(LC–MS–MS)要求配有电喷雾离子源。自2016年12月,食药总局发布《食品补充检验方法工作规定》以来,已经有超过10项的食品补充检验方法发布,且采用的分析方法中,液相和液相色谱–质谱分析方法比例超过50%。本次发布的检验方法的仪器与设备除采用了液相色     

液相色谱-串联质谱法测定果蔬中4种新型卵菌纲杀菌剂残留

建立了蔬菜和水果中噻唑菌胺、苯噻菌胺、氟啶酰菌胺和双炔酰菌胺4种新型卵菌纲杀菌剂的分散固相萃取-液相色谱-串联质谱检测方法.样品经乙腈均质提取,混合使用乙二胺-N-丙基硅烷(PSA)和ODSC18-N两种基质分散净化剂净化,采用液相色谱-三重四级杆串联质谱(LC/MS/MS)检测.实验通过空白基质溶液稀释标准建立校正的...     

高效液相色谱-串联质谱法测定纺织品中的致癌芳香胺

建立了高效液相色谱-串联质谱法(LC/MS/MS)测定纺织品中致癌芳香胺的检测方法.纺织品中的偶氮染料在柠檬酸缓冲液中用连二亚硫酸钠还原为芳香胺,用硅藻土提取还原液中的芳香胺,用乙醚洗脱,浓缩至近干后用甲醇定容.使用液相色谱-串联质谱进行测定,色谱柱为XTerra MS C18柱,流动相为甲醇和0.025 mol/L乙...     

GPC–HPLC–MS/MS法测定食用油中天然辣椒素、二氢辣椒素和合成辣椒素含量

以动植物油脂为实验材料,建立了测定食用油中天然辣椒素、二氢辣椒素和合成辣椒素含量的凝胶渗透色谱–高效液相色谱–串联质谱(GPC–HPLC–MS/MS)法。样品经凝胶渗透色谱净化后,采用液相色谱串联质谱法(HPLC–ESI–MS/MS)分析,多反应监测模式(MRM)下外标法定量。在0.1~5.0μg/L范围内线性良好,天然辣椒素、二氢辣椒素和合成辣椒素的相关系数分别为0.999 6,0.999 8,0.999 8,检出限为0.5μg/kg。在5μg/kg添加水平下,空白加标回收率为71.5%~82.5%,测定结果的相对标准偏差为3.0%~8.3%(n=6)。该方法样品处理过程简便快捷,测定结果准确,可满足实验室大量、快速分析的需求。     

喹啉黄中各组分的定性及定量研究

利用高效液相色谱(HPLC)对喹啉黄各组分进行分离并定量,通过液相色谱–串联质谱(LC–MS/MS)对各组分进行定性。以0.01 mol/L乙酸铵溶液和甲醇为流动相进行梯度洗脱,利用Agilent XDB–C18色谱柱对喹啉黄各组分进行分离,峰面积归一化法定量。质谱采用电喷雾负离子(ESI–)模式电离,多反应监测(MRM)模式检测,对喹啉黄各组分进行定性。结果表明,喹啉黄主要成分为喹啉黄一钠盐和喹啉黄二钠盐,分别各有两种同分异构体,各组分质量浓度在5.0~100.0μg/m L范围内与峰面积呈良好的线性关系。加标回收率为98.2%~99.1%,测定结果的相对标准偏差为0.90%~1.58%(n=6)。该方法具有良好的精密度和准确度,可用于喹啉黄中各组分的测定。     

《液相色谱质谱联用技术在食品和药品分析中的应用》

随着现代仪器分析的发展,液相色谱质谱联用技术(LC/MS)日趋成熟,并在科研与生产中发挥了重要作用。该书由三部分组成:第一部分基础理论,介绍了液相色谱和质谱的工作原理、仪器结构及工作条件、LC/MS接口、质谱信息解析;第二部分食品功能成分分析,介绍了LC/MS方法分析食品中的蛋     

《液相色谱质谱联用技术在食品和药品分析中的应用》

随着现代仪器分析的发展,液相色谱质谱联用技术(LC/MS)日趋成熟,并在科研与生产中发挥了重要作用。该书由三部分组成:第一部分基础理论,介绍了液相色谱和质谱的工作原理、仪器结构及工作条件、LC/MS接口、质谱信息解析;第二部分食品功能成分分析,介绍了LC/MS方法分析食品中的蛋     

Overview of Special Session B—Compositional and Structural Analysis of Biomass

Special Session B at the 29th Symposium on Biotechnology for Fuels and Chemicals was the first invited session at this symposium devoted to analytical methods. The special topic was added in response to numerous requests for information on new and innovative methods that could be applied in the growing renewable fuels industry. Presentation topics include analytical methods for the characterization and analysis of maize traits, tools for investigating cell wall limitations to enzymatic degradation, methods for customizing enzyme cocktails for biomass, new techniques for the analysis of carbohydrates, analytical methods that enhance our understanding of pretreatment, improved methods for monitoring process intermediates, and published standard analytical methods for biomass conversion processes.     

Stopped-flow and kinetic-fluorimetric determination of quinalphos in water samples

The hydrolysis of the pesticide quinalphos in basic medium was kinetically followed and the measurement of the reaction rates allowed us to develop two kinetic-fluorimetric methods. In one of them the mixing of the reagents was directly performed in the measurement cell and, in the another one, the stopped-flow mixing technique was used. The reaction was completed in 100 s after the reactants were mixed and it allowed the simple application of the proposed methods to routine analyses of the pesticide. The sensitivity of the methods was very high, being the detection limits 50 and 140 ng mL⁻¹ for the manual procedure and the stopped-flow mixing technique, respectively. Both methods were compared using regression with uncertainties in both axes. The effect of the presence of several pesticides in the determination was tested. A solid-phase extraction process was also developed for the application of the methods to diverse waters samples. The proposed kinetic-fluorimetric methods were applied to the determination of quinalphos in drinking water, well water and river water, with very satisfactory results.     

Response surface design as a powerful tool for the development of environmentally benign HPLC methods for the determination of two antihypertensive combinations: Greenness assessment by two green analytical chemistry evaluation tools

Interest in implementing green chemistry principles in analytical chemistry has grown dramatically in the past few years. The solvents used have the major influence on the greenness of the method. Most conventional high‐performance liquid chromatography methods employed utilize solvents that are “hazardous for the environment”. In the present study, two‐factor three‐level response surface design was exploited to develop eco‐friendly chromatographic methods for two different mixtures. The first one was atorvastatin and amlodipine and the second one was amlodipine, perindopril, and indapamide. As it is nontoxic to the environment, ethanol was used as the organic modifier in the mobile phase. The separation of the first mixture was attained using phosphate buffer (pH 7)/ethanol (42:58 v/v), and the second mixture was fully resolved using phosphate buffer (pH 5)/ethanol (40:60 v/v). The use of high‐performance liquid chromatography allows excellent resolution in a short run time, hence, less waste was produced. The greenness of the developed methods was assessed by two evaluation tools, namely, National Environmental Methods Index and analytical eco‐scale, and found to be excellent green analytical methods. Moreover, the developed methods were compared with other reported methods regarding accuracy and greenness and were found to be perfect alternatives to reported methods for separation and quantification of the mixtures.     

有机分子生成热计算的对比研究

采用20种理论方法计算了180个中小型有机分子的生成热.结果表明:HF是最差的方法,一般不宜采用;OLYP,B3PW91和M05-2X分别是GGA,Hybrid GGA和Hybridmeta-GGA方法中计算偏差最小的一种方法;对于所有的计算方法,中型分子的计算偏差要大于小型分子的计算偏差;小型分子和中型分子计算偏差最小的方法分别是B3PW91和M05-2X;M05-2X所计算的偏差比其他方法集中;随着分子尺度的增加,M05-2X,M06-2X,M06-HF和经典G4方法所计算结果的偏差呈波浪型缓慢增加.     

X-H (X = C, N, O, Si, P, S) 键离解能计算的密度泛函方法研究

使用了不同密度泛函方法计算X-H (X = C, N, O, Si, P, S) 键离解能，并分析不同密度泛函方法的计算精度。研究发现大多数密度泛函方法包括B3LYP, B3P86, B3PW91, G96LYP, PBE1PBE，和BH&HLYP都明显低估键离解能13-25 kJ/mol。该现象与是否使用无限基组无关，因为即使使用无限基组键离解能仍然被低估。因此密度泛函方法不适合用于键离解能的估算。其中B3P86方法的偏差最小。进一步分析表明，使用限制性开壳层计算并无任何优势，在大多数情况下非限制性开壳层计算实际上比限制性开壳层计算要好。最后，我们发现了密度泛函方法对键离解能的低估是系统的，因此建议利用校准后的UDFT/6-311++G(d, p)方法计算化学键离解能。     

原油成分分析方法的研究进展

综述了国内外关于原油成分,包括饱和烃、芳香烃、胶质及沥青质等的主要分析方法,指出了各分析方法的特点与不足,展望了这些分析方法在原油成分分析中的应用前景(引用文献32篇)。     

Ab initio and density function theory computational studies of the CH4 + H → CH3 + H2 reaction

The activation barrier for the CH₄ + H → CH₃ + H₂ reaction was evaluated with traditional ab initio and Density Functional Theory (DFT) methods. None of the applied ab initio and DFT methods was able to reproduce the experimental activation barrier of 11.0-12.0 kcal/mol. All ab initio methods (HF, MP2, MP3, MP4, QCISD, QCISD(T), G1, G2, and G2MP2) overestimated the activation energy. The best results were obtained with the G2 and G2MP2 ab initio computational approaches. The zero-point corrected energy was 14.4 kcal mol⁻¹. Some of the exchange DFT methods (HFB) computed energies which were similar to the highly accurate ab initio methods, while the B3LYP hybrid DFT methods underestimated the activation barrier by 3 kcal mol⁻¹. Gradient-corrected DFT methods underestimated the barrier even more. The gradient-corrected DFT method that incorporated the PW91 correlational functional even generated a negative reaction barrier. The suitability of some computational methods for accurately predicting the potential energy surface for this hydrogen radical abstraction reaction was discussed.     

食品中铝检测方法研究进展

介绍了食品中铝的来源,并综述了近十年中食品中铝测定方法的研究进展,包括电感耦合等离子体原子发射光谱法、电感耦合等离子体质谱法、石墨炉原子吸收光谱法、电化学分析法以及分光光度法等方法(引用文献75篇)。     

废弃油脂生产生物柴油的研究进展

简单介绍了生物柴油的生产原料,综述了用废弃油脂生产生物柴油的现状和方法。废弃油脂生产生物柴油的方法主要有物理法和化学法,物理法主要有掺和法和微乳法,化学法主要有热裂解法和酯交换法。目前生产中采用化学法的酯交换法、以酸碱两步催化法的工艺为主,而生物酶法和超临界法是研究热点。     

在碱性DMSO体系中酚红电还原机理研究

本文应用电化学方法、顺磁共振一电化学技术、光谱电化学三种方法洋细研究了酚红在碱性(四丁基氢氧化铵)二甲亚砜(DMSO)溶液中的电化学还原行为, 确定了中间产物自由基, 并拟定了该自由基的结构, 提出了后续化学反应的决定步骤为歧化反应的EC机理。