气相色谱内标法测定化妆品中的甲醇和乙醇含量

建立了气相色谱内标法测定化妆品中甲醇和乙醇的方法。通过考察稀释液、内标物和气相色谱柱等条件,以N,N-二甲基甲酰胺作为稀释液,异丙醇作为内标物,选用DB-FFAP毛细管柱进行色谱分离,保留时间定性,内标法定量,并与《化妆品卫生规范》(2007版)中气相色谱顶空外标法测定甲醇的方法进行了比较。结果表明,用气相色谱内标法测定化妆品中甲醇和乙醇的含量,在0.8 mg/L～500 mg/L范围内具有良好的线性关系(R2甲醇=0.999 8和R2乙醇=0.999 7),相对误差<2.4%,回收率为92.7%～104.7%(n=6)。     

气相色谱法测定甲醇中杂质含量

采用CP7381毛细管柱,以甲醇为溶剂、丙酮为内标物,利用毛细管柱、氢火焰离子检测器检测,测定工业用甲醇中杂质乙醇、甲酸甲酯、正丙醇、异丙醇含量。试验结果表明：本方法测定标准溶液中各杂质组分含量的相对误差为3．11％-4．51％,相对标准偏差为0．93％-1．96％,具有较好的准确度和精密度,可用于对工业用甲醇中杂质的质控分析。     

乳癖消贴片中标示成分及残留溶剂的含量测定

建立了贴片中标示成分芍药苷含量的HPLC分析方法和贴片中各种残留溶剂含量的GC分析方法。样品经甲醇提取,离心分离后,以乙腈-水（体积比16：84,HAc0．4％）为流动相,选择ODS-2Hypersil C18（4．6mm×150mm,5μm）色谱柱,测定芍药苷含量。贴片基质经处理,以GC内标法测定残留溶剂含量。结果表明HPLC法的精密度、重现性和回收率良好;GC分析测得乙酸乙酯、异丙醇、乙醇三种残留溶剂,贴片中残留溶剂总量为2．1×10^-4。     

气相色谱法测定防冻液中乙醇的含量

建立了防冻液中乙醇含量的气相色谱分析方法。采用Agilent7890气相色谱仪,FID检测器,DB-170160m×0.32mm×0.25μm毛细管色谱柱,以异丁醇为内标,以乙腈为溶剂。内标法对防冻液中的乙醇含量进行定量分析,乙醇浓度与内标浓度的比值在0.5∶1～2.5∶1(g)之间的范围内线性相关系数为0.9999,平均回收率99.5%,样品测定的标准偏差0.051,变异系数为0.99%。     

GC-FID内标法测定复方丹参制剂醇沉上清液乙醇含量

目的建立GC-FID内标法,快速、准确测定复方丹参制剂醇沉上清液乙醇含量。方法以正丙醇为内标物,采用Agi Lent DB-624(30m×0.53mm×3μm)色谱柱,氢火焰离子化检测器检测。结果该方法在乙醇体积分数为0.00999%～0.069930%范围内呈现良好的线性关系(R~2=0.9998);加标回收率为97.39%～102.54%,RSD为0.53%～1.56%。结论方法简便快捷、准确可靠,可用于复方丹参醇沉上清液乙醇含量的测定。     

气相色谱法定量分析助磨剂中的醇胺类物质

<正>水泥助磨剂中醇胺类物质主要包括三乙醇胺(简称TEA)、三异丙醇胺(简称TIPA)和新型三异丙醇胺(包含二乙醇单异丙醇胺和单乙醇二异丙醇胺等,前者简称DEIPA)等。目前测定TEA和TIPA的方法有非水滴定法[1]、气相色谱法[1-3]等。非水滴定法操作复杂,测定速度慢,不能分别定量出助磨剂中这两种组分各自的含量。文献[1-4]中采用过极性柱和弱极性柱测定TEA和     

二嗪磷原油的气相色谱分析

采用气相色谱法 ,选用OV 17玻璃柱 ,邻苯二甲酸二丁酯为内标物 ,测定二嗪磷原油中有效成分的含量。方法的标准偏差为 0 19% ,变异系数为 0 2 0 % ,回收率为 99 5 1%～ 10 0 2 %     

气相色谱内标法测定2-甲基吡啶和2-羟乙基吡啶的含量

利用气相色谱内标法测定2-甲基吡啶和2-羟乙基吡啶的含量,以吡啶作为内标物,乙醇作溶剂,使用FFAP毛细管色谱柱和FID检测器,对缩合油进行分离与定量。2-甲基毗啶的线性相关系数为0．9995,标准偏差为0．30,变异系数为0．61％,平均回收率为99．76％;2-羟乙基吡啶的线性相关系数为0．9994,标准偏差为0．31,变异系数为1．35％,平均回收率为99．22％。     

柱前衍生化法结合HPLC测定2-哌啶乙醇对映体光学纯度

用3,5-二硝基苯甲酸对2-哌啶乙醇进行柱前衍生,将其衍生物在Chiralcel OD-H手性固定相上拆分,建立了一种拆分2-哌啶乙醇消旋体、测定2-哌啶乙醇光学纯度的新方法。以正己烷与乙醇或异丙醇为流动相,在Chiralcel OD-H手性固定相上对2-哌啶乙醇衍生物进行了拆分,并考察了流动相组成、柱温和流速对该对映体分离的影响,获得较优分析条件,分析时间在15分钟内,分离度大于1.7。结果表明,2-哌啶乙醇衍生物对映体在正己烷-乙醇(体积比85:15)为流动相、流速为1.0mL min-1、柱温为30℃时,分离效果最佳。本方法操作简单、重现性好,可用于2-哌啶乙醇对映体的质量控制。     

气相色谱法测工业三乙醇胺

以聚甲基硅橡胶毛细管柱为色谱柱 ,乙醇为溶剂 ,氢火焰离子检测器检测 ,分别对工业三乙醇胺中一乙醇胺、二乙醇胺、三乙醇胺进行分离 ,进而测出其含量。并对色谱柱、载气流速、柱温溶剂、进样量等色谱条件的选择 ,以及试样与溶剂的体积比的选择进行了实验。利用保留时间定性 ,对归一化法、内标法、外标法进行了对比实验 ,结果归一化法快速可行。在选定的最佳色谱条件下 ,三乙醇胺样品回收率的测定结果在 98.72 %～ 1 0 3.2 %之间。精密度为 CV=0 .40 3%。对实际样品测试结果 ,色谱法相对标准偏差 CV=0 .1 35% ,化学法相对标准偏差 CV=1 .81 % ,而色谱法不用对分析样品处理 ,操作简单、快速 ,便于工业实际生产监测。     

乙烯酮(双乙烯酮)下游产品废水的治理技术

乙烯酮(双乙烯酮)是十分重要的化工中间体,其下游产品较多。江苏某化工厂开发生产乙烯酮(双乙烯酮)下游产品三十多个,年生产规模三万多吨,是国内以乙烯酮(双乙烯酮)为中间体生产精细化学品的综合骨干企业。针对乙烯酮(双乙烯酮)下游产品废水特点,该厂结合企业实际,开展了产品优化,结构调整,清洁生产,资源循环利用,节水降耗等工作,从源头削减了污染物的生产。同时投资二千多万元新建预处理装置三套,6000m3/d废水生化处理装置一套,使全厂乙烯酮(双乙烯酮)下游产品的废水得到了有效的治理。     

几种乙炔加压设备性能的比较

阐述并比较了几种加压设备在乙炔加压清净过程中的性能和特点。     

三种煤样燃烧热的测定

本文通过三个厂家提供的三种煤样燃烧热的测定,由测定结果综合得出3号煤样燃烧最完全、燃烧热也最大,是三个煤样中最好的一种。     

Semi-empirical equation of state of metals. Equation of state of aluminum

A semi-empirical equation of state for metals is described. Its capabilities are demonstrated by the example of the equation of state for aluminum. New experimental data are presented on the location of the isentrope of aluminum for unloading from the state at p = 229.71 GPa on the shock adiabat to an aerogel (SiO₂) of density 0.08 g/cm³. __________ Translated from Fizika Goreniya i Vzryva, Vol. 44, No. 2, pp. 61–75, March–April, 2008.     

水泥水化热测定方法综述

水泥水化热是中、低热水泥和核电工程用水泥的一项关键的技术指标。全球范围内测定水泥水化热的方法有溶解法、直接法/半绝热法、等温传导量热法三种。本文总结了中、美、欧相关方法标准,对其测试原理、仪器设备、试验过程等方面进行了比对,并对其在领域的应用做了简单的概括。     

小议汽车涂装工艺设计对涂装成本的影响

论述了涂装工艺设计对涂装设备投资、涂装生产成本的影响。     

Measurement of the gradient of viscosity with composition of mixtures of non-ideal gases

A perturbation viscometer is a differential capillary viscometer that measures the logarithmic viscosity gradient of the viscosity-composition curve for gas mixtures. Measurements are made at different gas mixture compositions. Integration of the logarithmic viscosity gradients measured over the full composition range gives the mixture viscosity relative to the viscosity of one of the pure components of the gas mixture. This method is attractive because, for measurements of equal precision, integration of the gradients is potentially an order of magnitude more precise than measurement of the viscosities directly. It can also work at high and low temperatures and perhaps high pressures.The perturbation viscometer has been used to make measurements on ideal gas mixtures at ambient and elevated temperatures. The situation is more complicated when the gas mixtures are non-ideal. Extra effects due to density differences, molar volume change on mixing and differential thermal expansion may be measured in addition to the desired viscosity change producing systematic errors in the results. Thus, a more sophisticated apparatus is required. The standard perturbation viscometer has been modified to separate out the extra effects to permit measurement of the true change in viscosity. In addition, the theoretical operation of the modified apparatus has been revised to account for the design changes to permit calculation of the viscosity-composition profiles from the results.The apparatus has been tested using helium-HFC-125 mixtures and two new viscosity-composition profiles are presented for these mixtures at 23 and . Internal consistency tests have been used to confirm that the data produced are of high quality with an estimated uncertainty in the viscosity ratio data at of 0.9% and at of 1.5%.     

Calorimetric and Computational Study of Enthalpy of Formation of Diperoxide of Cyclohexanone

A thermochemical rather simple experimental technique is applied to determine the enthalpy of formation of Diperoxide of ciclohexanone. The study is complemented with suitable theoretical calculations at the semiempirical and ab initio levels. A particular satisfactory agreement between both ways is found for the ab initio calculation at the 6–311G basis This set level. Some possible extensions of the present procedure are pointed out.     

塔设备改造选型的分析

就当前扩产增容中塔设备设计和改造时板式塔和填料塔的选型问题加以分析。在评述目前国内常用的几种塔板和新型填料之后，着重介绍一种新型塔板（导向梯形浮阀塔板）和一种新型填料（波环填料——乾隆帕克）。     

Effect of degree of deacetylation of chitin on the properties of chitin crystallites

In the present article, chitin from crab shell was systematically deacetylated using a NaOH treatment with control of the reaction time. The degree of deacetylation, monitored using solid-state NMR, revealed that the reaction was pseudo-first order. Based on this, swollen and NaOH-saturated particles are proposed as the reaction system. The weight loss of the partially saponified and neutralized samples after HCl hydrolysis increased linearly with the degree of deacetylation. The crystallinity of the samples was found to increase after acid hydrolysis. According to conductimetric titration, the surface charge density of the crystallites, after acid hydrolysis, was found to increase with base treatment time. The effect of surface charge on the formation of a chiral nematic phase, due to the rodlike nature of the crystallites, was explored. These results show that because the contribution of charged particles to the ionic strength was significant the double layer compression was affected, especially since the surface charge density was close to the Manning limit. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 65:373–380, 1997