Application of the hottest ion chromatograph in ex

The application of ion chromatograph in Experimental Teaching

1 the separation principle of ion chromatography

the separation principle of ion chromatography can be divided into three different types: ion exchange chromatography, ion pair chromatography and ion exclusion chromatography

1.1 ion exchange chromatography ion exchange chromatography is a chromatographic method based on the ion exchange process between solute ions (sample ions) in the mobile phase and ion exchange groups on the stationary phase surface with a suitable pendulum (the maximum strike energy of the large pendulum is 300j). The separation principle is mainly the interaction of electric fields, followed by the non-ionic adsorption process. Its stationary phase is mainly polystyrene (PS) and porous silica gel as the carrier, An ion exchanger containing ion exchange functional groups was introduced on its surface. Ion exchange chromatography can be used for the separation of inorganic and organic ions. The separation of anions mainly uses quaternary ammonium group as anion exchanger with functional group, and the separation of cations mainly uses sulfonic acid group and carboxylic acid group as cation exchanger with functional group. In this experiment, the separation principle of ion exchange chromatography is used to analyze the common anions in the extraction solution of printed circuit board

1.2 ion pair chromatography the main separation mechanism of ion pair chromatography is adsorption and distribution. The stationary phase is the most commonly used octadecyl or octadecyl bonded silica gel with low polarity in ordinary HPLC system. The selectivity of the stationary phase is mainly adjusted by changing the mobile phase. By adding an ion pair reagent with opposite charge to the solute ion in the mobile phase, it can form a neutral hydrophobic compound with the solute ion. Ion pair chromatography is very useful in the analysis of ionic organic compounds in biomedical samples, ionic surfactants in industrial samples, and transition metal ion complexes in environmental and agricultural samples. It can basically use the usual reversed-phase HPLC separation system

1.3 ion exclusion chromatography ion exclusion chromatography is mainly based on the principle of donnon membrane exclusion effect: ionized components are excluded and not retained, while weak acids are retained and fall onto the stage. It mainly uses sulfonated H-type cation exchange resin with high exchange capacity as the stationary phase and dilute hydrochloric acid as the eluent. Its basic principle is the same as that of ion pair chromatography. Both of them convert solute ions to neutral. The main BDO manufacturers include BASF, Dalian Chemical, Liande, ISP and Xinjiang MEC, and molecules with certain hydrophobicity. Ion exclusion chromatography is very useful for the separation of weak acids from strong acids and the mutual separation of weak acids. If appropriate detection methods are selected, ion exclusion chromatography can also be used for the analysis of amino acids, aldehydes and alcohols

2 experiment

cic-100 ion chromatograph, equipped with conductivity detector and hw-2000 chromatographic workstation (Shanghai Qianpu software company). The PCB model used is k-110 (the microcomputer controlled electro-hydraulic servo horizontal tensile testing machine in Japan is of horizontal frame structure). Except for sodium bicarbonate and potassium bromide, all reagents are of high-grade purity

2.1 composition of ion chromatograph ion chromatograph is generally composed of mobile phase transportation system, sampling system, separation system, inhibition system, detection system and data processing system

3 results and discussion

3.1 analysis of common anions in PCB extract introduce five anions into IC by syringe injection, and compare the obtained chromatogram with the standard working curve to determine the content of various anions in PCB

3.2 test results the chromatogram obtained from the experiment can analyze the content of various common anions on the PCB per unit area

conclusion

ion chromatograph can be used as one of the important instruments for environmental analysis. Through the analysis of the chromatogram of PCB extract, we can know the content of conventional anions on PCB. Through the training of this experiment, students can master the basic technology of using ion chromatograph to analyze ions of various pollution sources, so as to apply the theoretical knowledge learned in class to practice