Paper chromatography, thin layer chromatography, high performance liquid chromatography and gas chromatography are widely applied chromatographic techniques. They have their own advantages and disadvantages and application scopes.

Paper chromatography is the cheapest one of them, however, its time of spreading is long. It is usually used for separating water-soluble substances.

The advantage of thin layer chromatography is simple equipment and opeation, fast spreading, wide measurement. No matter inorganic, organic, biological and drugs etc., they all can be analyzed by thin layer chromatography. From the view of nature of compound, the separation, identification and quantitative analysis of small molecular or macromolecular compounds, water-soluble or non-water-soluble substances can be made by thin layer chromatography.

The precision and stability of quantitative analysis of high performance liquid chromatography are better than thin layer chromatography, however, the price of equipment and operation cost are expensive.

The accuracy of quantitative analysis of gas chromatography is high, however, it is only applicable to the compound which can be vaporized at the column temperature of equipment (Generally the temperature is 200℃ to 300℃). So, it limits its application range. In organic compounds, gas chromatographic analysis are suitable for only about 20% - 30% products. In practise, the application of gas chromatography is relatively less. However, it still has advantages which can not be replaced by liquid chromatography.