Study and Compatible Design of Two Types of Liquid Auto Sampler for Gas Chromatographer / 分析化学

ABSTRACT

We carried out parallel design and development of two differently structured auto sampler based on a multi-axis and multi-mode high-precision closed-loop servo control system. An integrated embedded control drive module was developed based on the idea of compatibility and inter-changeability, so that DC motor and encoder were standardized into uniform models. Meanwhile, electric and mechanical interfaces were uniformed to a same standard. This allows the direct exchange of above-mentioned components between the two models. A 1-μL manual sample injection syringe was installed on both standard 110-sample and platform 40-sample liquid auto sample injectors connected with gas chromatographer. Approximately 0. 5μL of cetane-isooctyl was sampled for 6 consecutive times at six different positions in the sample bottle. The repeatability RSDs of the injection peak areas of the two systems were 1. 1% and 1. 5%, respectively. A linear correlation coefficient (0. 9947) of peak area with injection volume was achieved based on the gradient sampling volume of 0. 1, 0. 3, 0. 5, 0. 7 and 0. 9 μL.