| 摘要 |
<p>A conventional injection valve, such as used in high performance liquid chromatography apparatus, having six ports (1 - 6) and three channels (64A,64B,64C;82A,82B,82C) for connecting the ports in two different positions, is modified so that one (64A;82A) of the channels is longer than the other two. In this way, when the valve is switched to the load position, one of the ports is always connected to the channel prior to the other port being connected. This improvement makes the valve more accurate and reduces undesirable mixing of sample and mobile phase in the valve when injecting small quantities of sample.</p> |
