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A smallbore chemically bonded alkyl stationary phase column of 2 mm I. D.(inner diameter) and 15 cm in length having an efficiency of 6400—7600 theoretical plates has been developed. The column officicncy is nearly the same as that of routine analytical column of 4.6—5.0 mm I. D. The amount of cluant used for the smallbore column, however, is less than about one fifth that for the ordinary columns.Using the reaction of monochlorosilane with 5 μm accumulated silica bead produced in Qingdao Ocean Chemical Factory instead of trichlorosilane and irregular silica gel, we have. prepared a nonpolar chemically bonded phase packing which has a higher carbon content and more obvious hydrophobicity. Moreover, the reproducibility of the preparation is better.The equipment and assembly necessary for getting high efficiency with the smallbore column are discussed briefly. Using Model SW-1 smallbore column HPLC instrument developed in the institute with the Model K-1 column fittings and injector, the detector with 相似文献
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The performance of small-bore columns of 1 mm I. D. for HPLC is described. The effect of mobile phase velocity and connecting effect on the values of H, a′, b′ and β are investigated. By operating at mobile phase velocity of 0.8 mm/s, the column of 200×1 mm I. D. packed with YWG-5μm (silica gel) can give the efficiency of about 11,000 plates which meet the needs of ordinary analysis. Oompared with column of 150×2 mm I. D., the solvent consumption is reduced to 1/3. The value of n~∞/t_r~0 about 700 T. P./s can be obtained. But the value of β is rather large. It needs further to be improved. Coupling 5 columns of 200×1 mm I. D., the efficiency of about 50,000 plates can be obtained. For a column of 1000×1 mm I. D. packed directly, the efficiency of 70,000 plates was achieved. Some applications of 1 mm I. D. column are given. We propose to use the column of 200×1mm I. D. in the routine analysis. 相似文献
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保持载气流速的稳定,是保证工业色谱仪长期连续运转中准确工作的控制因素之一。为此目的,通常采用两种方法:一种是在色谱仪柱前加稳流系统,使载气流速在任何情况下恒定不变;另一种是色谱仪的柱前稳压,当色谱系统阻力一定时,保持柱前载气压力恒定,则其流速即恒定不变。一般常用的“氧气减压阀”、“稳压阀”、“压力定值器”等都属于后一种。目前色谱仪载气的稳定主要是采用稳定柱前载气压力的办法。但是,在柱前稳压的条件下,柱出口压力(即大气压力)的自然变化对载气流速的影响常常被人们所忽视,而在某些大气压剧烈变化的情况下, 相似文献
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反相液相色谱保留值的预测模式 总被引:2,自引:0,他引:2
液相色谱保留值的预测一直是色谱领域里研究最为活跃的领域之一,寻找一种以最少系数求算和预测色谱保留值是色谱工作者的长期研究的目标,但目前,仍没有真正的预测方法。我们在液相色谱保留值基本方程的基础上,曾对不同C_(18)的担体上的保留规律进行过研究,并从中引入了溶质lnk′=A C·C_B BlnC_B (1)作用指数的概念,作用指数即为方程(1)中的参数C(参数B在反相色谱中忽略),CB为二元冲洗剂中强冲洗组分的浓度。本文从溶质的作用指数出发来探讨反相液相色谱保留值的预测模式。 相似文献