1.Solid phase extraction technology.
Solid phase extraction (SPE) is a commonly used sample preparation technique to achieve the separation and enrichment of target compounds by physical or chemical adsorption of solid sorbents and target compounds in liquid samples. In lignin determination, solid-phase extraction technology can be used to extract and purify lignin from soil samples to improve the sensitivity and accuracy of the determination method.
2.Gas chromatography.
Gas chromatography (GC) is a commonly used separation and analysis technique in which components in a gas or volatile liquid are separated by a chromatographic column, and then detected and quantified by a detector. In the determination of lignin, gas chromatography can be used to separate and determine lignin components in soil samples, which has the advantages of good separation effect, fast analysis speed and high sensitivity.
3.Soil sample processing.
Soil sample treatment is the first step in the determination of lignin, which usually includes the collection, crushing, sifting, drying and other steps of soil samples to remove impurities and water from them. At the same time, it is also necessary to acidify the soil samples to destroy humus and other interfering substances and improve the accuracy of lignin determination.
4.Extractant selection.
Selecting the right extractant is one of the key steps in the solid-phase extraction process. For the determination of lignin, organic solvents with strong polarity are generally used as extractants, such as ethyl acetate, acetone, etc. These solvents are effective in dissolving lignin components in soil samples and separating them from the sample matrix.
5.Elution conditions are optimized.
During solid-phase extraction, elution conditions have an important impact on the rate and purity of the target compound. Therefore, the elution conditions need to be optimized to obtain the best elution results. Elution conditions can often be optimized by changing factors such as the type, concentration, and flow rate of the eluent.
6.Detection method establishment.
In the process of determining lignin by gas chromatography, it is necessary to establish corresponding detection methods. This includes selecting the appropriate column, detector, inlet temperature, column temperature program, and other parameters. By optimizing these parameters, the separation and detection sensitivity of lignin components can be improved, resulting in more accurate results.
7.Experimental operation specifications.
When performing solid-phase extraction-gas chromatography for the determination of lignin in soil, it is necessary to strictly follow the experimental operation specifications. This includes the proper use and maintenance of equipment such as solid-phase extraction devices and gas chromatographs to ensure the accuracy and reliability of experimental results. At the same time, it is also necessary to pay attention to safety issues during the experiment, such as avoiding the use of flammable and explosive organic solvents.
8.Analysis and application of results.
After the determination of lignin content in soil by solid phase extraction-gas chromatography, the results need to be analyzed and applied. This includes comparing the lignin content in different soil samples, analysing the relationship between lignin content and soil properties, etc. At the same time, the measurement results can also be applied to soil quality evaluation, environmental pollution monitoring and other fields, providing a scientific basis for related research and application.