样品过滤在液相色谱分析中的重要性

Sample filtration plays a major role in analytical chemistry. Filtration is a practice where a liquid is freed from suspended solid impurities. The technique is commonly employed in wet chemistry for separation of precipitates for further quantitative analysis or for removal of interfering suspensions in spectroscopic studies.

In chromatographic analysis sample filtration before injection becomes all the more important for different reasons. After injection the sample is carried to the chromatographic column and subsequently to the detector. Any particle impurities if present in the sample will start blocking the chromatographic column leading to irregularities in flow rate which can shift retention times of peaks or to complete stoppage of mobile phase flow. Such problems may be overcome with column washing but in severe cases the expensive column needs to be replaced.

固体悬浮液还可沉积在检测电池中，这可能导致鬼魂峰的过度噪音和外观。过度沉积甚至可以导致压力积聚和对细胞壁的损坏。

In classical analysis filtration is carried out using coarse paper filters but due to strict restriction on particle size in chromatographic analysis special membrane filters are required. Generally 0.45 µ size membrane filters are fine but for small diameter capillary columns packed with packings under 3μm will require 0.2 μm size filters. These membrane filters are wetted with the mobile phase and placed in the filtration syringe. Filtered samples are collected into the sample vials and capped properly.

Teflon filters are useful for organic solvents. Nylon filters can be used for both aqueous as well as organic samples but acidic samples should be filtered using PTFE-based membrane filters.

It goes without saying that the objective of sample filtration would get defeated if the mobile phase itself is not filtered. For this purpose the inlet tubing immersed in the mobile phase container should be fitted with stainless steel or ceramic particle filtration frits of specified sizes.

强烈建议采样和流动相过滤，因为它不仅会提高结果质量，而且还将延长柱寿命并降低系统组件的维护成本和时间

注射器过滤器可用于来自几种来源的HPLC样品纯化。这里提到了一些着名的供应商：

1. Pall Corporation.
2. Millipore.
3. Sartorius
4. Spartan Syringe filters
5. Whatman
6. La-Pha-pack
7. Cole Parmer