共查询到20条相似文献,搜索用时 412 毫秒
1.
《广东化工》2021,48(13)
目的:比较不同前处理方法对连翘中连翘苷的萃取效率的影响。并建立检测连翘苷的方法,利用建立的方法对双黄连口服液中连翘苷进行鉴别和含量测定。方法:采用高效液相色谱法,以ODS C18(150 mm×4.6 mm×5μm)不锈钢柱为色谱柱,乙腈-水(25∶75)为流动相,检测波长为278 nm,流速1.0 mL/min,以外标法按峰面积计算连翘苷的含量为参考指标,来探讨不同前处理方法的提取效率。然后采用薄层色谱法来鉴别双黄连口服液中连翘苷。结果:正相分配色谱法萃取连翘中连翘苷的分离效率高于反相分配色谱法。双黄连口服液中含有连翘苷。结论:正相分配色谱法比反相分配色谱法分离效率更好。薄层色谱法直接就可鉴别双黄连口服液中含有连翘苷,操作简便。 相似文献
2.
3.
4.
三种X射线物相定量分析方法对比研究 总被引:5,自引:0,他引:5
为研究比较不同X射线定量分析方法的优缺点,对CeO2-TiO2二元混合物体系样品分别用内标法、K值法和绝热法进行定量分析,着重比较了三种方法在实验步骤、可操作性和结果相对误差等方面的差别.结果表明,内标法操作程序较复杂,结果误差较大,不便在实际操作中推广应用;绝热法是实际应用中较便捷、误差较小的定量分析方法.然而应用绝热法进行定量分析时,要减小实验误差就必须获得待测物相准确的参比强度值(即K值),因此定性分析是其关键步骤. 相似文献
5.
采用安捷伦气相色谱7890完成苯乙烯纯度测定的内标法建岗,并与面积归一化法比较。内标法是通过测量内标物与被测组分峰面积的相对值来进行计算,测定的结果较为准确。缺点是操作程序较为麻烦,每次分析时内标物和试样都要准确称量。 相似文献
6.
建立了阳极电泳涂料中有机溶剂含量的顶空毛细管气相色谱分析方法。选用大口径HP-快速GC残留溶剂柱为分离柱,FID为检测器,内标法进行定量,并讨论了顶空平衡温度、平衡时间对测定的影响。分析结果表明:该方法对有机溶剂达到了完全分离,溶剂和内标乙二醇乙醚的不同质量比与其相应特征峰的峰面积之比有较好的线性关系,相关系数为0.9993~0.9997,测定结果的RSD为1.12%~2.65%,样品的回收率为98.87%~100.35%。 相似文献
7.
8.
9.
10.
为了提高醇类燃料中甲醇含量测量的准确度和精密度,建立了以乙醇作为内标物用气相色谱测定甲醇汽油中甲醇含量的分析方法。通过实验,考察了分流比、阀切换时间等因素对实验结果的影响,确定了最佳实验条件;同时对该方法的准确度和精密度进行了验证。结果表明:在柱温60℃、汽化室温度230℃、检测器温度250℃,载气流速30mL/min的条件下,色谱分离效果好。对同一样品分析,标准差为0.1062,变异系数为1.11%;对自配的5个不同浓度的样品进行分析,相对误差均小于5%。相对于其他方法而言,用气相色谱法测量提高了分析的精密度和准确度,适用于低比例甲醇汽油中甲醇含量的测定。相对外标法而言,内标法准确度高,且重复性好。 相似文献
11.
12.
13.
14.
15.
16.
17.
使用气相色谱进行甘油制备环氧氯丙烷过程中产品以及中间体的定量分析。色谱柱为Dexsil-300填充柱,色谱分离在程序升温条件下进行。分别采用了面积归一化法、校正因子法与内标法对甘油、二氯丙醇以及一氯丙二醇进行了定量,并进行了比较。结果表明,使用Dexsil-300填充柱与毛细柱相比,分析时间短;内标法与其它两种方法相比,不受其它副产物影响,准确性高,重现性好。甘油、二氯丙醇及一氯丙二醇含量测定的相对标准偏差分别为1.06%,1.17%以及1.18%,回收率分别在98.70%~101.11%,98.17%~102.56%以及97.61%~102.88%之间,能够准确的反映反应进行的程度。 相似文献
18.
Studies were conducted on separation of organic substances with different boiling points and polarity when simultaneously
present in water by capillary gas-liquid chromatography on a Kristall 2000 m chromatograph. The effect of the column phase
and temperature conditions on the separation factor and component exit time was investigated. Column temperature programming
was used to reduce the component, especially heavy component, retention time. The chromatography regime was selected and a
fast method was developed for determining components with different volatility in water during one analysis with sufficiently
high reproducibility and reliability of the results. It was shown that the time of the analysis decreased by more than two
times with the same accuracy as with the standard methods. The method can be recommended for fast analysis of wastewaters
for making a decision on the treatment method. 相似文献
19.
Two integration procedures for improving the precision of a.c. polarography have been studied. Both methods are single electrode techniques and involve integration of the rectified a.c. current over the complete peak or at the peak potential respectively. The time integration procedure was found to be seriously influenced by small variations in the reference electrode potential and applied voltage, resulting in poor reproducibility between different samples. In the area integration procedure, however, where the accurate control of potential is less critical, the standard deviation between replicate samples was found to be within the statistically expected limits and this method was therefore preferred. Standard deviations were measured for a range of inorganic and organic species and typical values of ±0.25% at the optimum concentration level (4.10–4M) were obtained. 相似文献