在色谱分析中自动注射的好处

色谱结果的准确性和精度在很大程度上取决于精确注射体积的重复性。这样的体积通常落在µL范围内。负责结果一致性的其他促成因素是操作参数，例如流动相组成和流量，控制柱温度的控制，流动相溶剂或气体的纯度，免受泄漏的自由，检测器波长和柱的效率。本文详细介绍了自动注射在实现所需目标中的作用。

The commonly adopted means of sample introduction are:

• 手动注射器注射
• 使用带有固定体积样品环的阀门注射
• 带有自动采样器的自动样本介绍

手动注射器注射

Syringe injection is the most common sample introduction practice. It is the most economical option which permits manual volume selection and introduction into the system. However, the selected volume is dependent on personal judgment and there is the possibility of errors from person to person or even the same person making repeat injections. Syringe injection can be relied upon only if proper使用和处理注射器时要注意。此类要求是耗时的，甚至经验丰富的色谱仪无法保证注射体积的重复性。注射器是精致的设备，因此在使用过程中需要仔细处理，并在随后使用之前进行精心清洁。

Injections using valves with fixed volume sample loops

The next popular device is a fixed volume loop injector. The advantage offered is constant injection volume which is decided by the volume of the sample loop. However, if the loop is not flushed adequately by the mobile phase the residues left over from earlier analysis can result in undesired impurity peaks in the chromatogram.

Automated Sample introduction using autosamplers

最好的选择是借助AutoSampler自动注入。它具有与手动注射相比的几个优点。

注射量

注射量由软件设置，因此没有个人错误。如果需要，可以重置该卷以满足分析要求。

重复注射

可以在软件的帮助下优化每个小瓶重复注射的数量，以获得所需的结果可重复性。在没有人类干预的情况下，这一切都是可能的。如果手动进行重复注射，则无法进行如此高的精度注射。

Vial selection

The autosampler tray has numbered slots for positioning of sample vials. The autosampler is pre-programmed to select the vials in the desired sequence for making injections. The sequence can be modified during runs to handle priority samples. This is a big benefit as it eliminates selection of vials manually.

清洗周期

必须在重复注射之间清洗带有毛坯的自动采样器注射器和针头。可以根据分析要求对洗涤周期及其顺序进行编程。

Injection of standards

It is essential to inject standard solutions in between sample injections to help verify the system performance. The number of standards to be injected and their sequence can be programmed in advance.

A large number of samples

在单个加载中，可以将100个或更多的样品或标准标准加载到AutoSampler托盘的编号位置。从编号位置进行注射遵循计划的序列和从此类小瓶中进行的选择错误。

节省时间

自动采样器提供的最大优势是节省时间。准备样品并加载样品并设置分析序列后，分析师可以免费处理其他任务。当没有人在周围时，自动样品甚至在一夜之间运行。此功能可显着增加实验室样品吞吐量。