Quality Assurance of Ion Chromatography Results

As one of the fastest growing analytical techniques in recent 40 years, ion chromatography has the advantages of good selectivity, high sensitivity, fast and easy, and simultaneous determination of multi-component. It has been widely used in many fields. When measuring samples with ion chromatography, effective quality control can reduce the experimental error in the analysis and ensure the accuracy and comparability of the measurement results.
1, select the appropriate method
Method is to analyze the core of the test, only select the appropriate method to ensure the accuracy and reliability of the data, it should give priority to the latest international, regional, national or industry standard method.
2, blank experiment
The significance of blank sample determination
    It is possible to estimate the error of laboratory water, vessel cleanliness, instrument performance and personnel handling skills and the possible errors of each analysis step. The blank value not only affects the detection limit of the method, but also affects the accuracy of the measurement results.
Precautions
1, the preparation of eluent used reagents, should try to use excellent grade pure.
2, experimental water are ultra-pure water.
3, injection, at least need to be injected into the quantitative tube more than 5 times the volume of the volume of the sample solution.
3, the impact of eluent
    The composition of the eluent, the concentration of eluent, the pH of the eluent, and the flow rate of the eluent will affect the peak area and peak height
Precautions
1, due to the process of storage in the eluent easily absorb CO2 in the air, the analysis of the stability of the baseline, resulting in error analysis results. Therefore, the preparation of a good eluent should not be long put, the best use according to the amount of temporary use.
2, the analysis process according to the separation effect to select the appropriate flow rate.
3, according to the different separation column configuration of different eluent.
4, the standard solution configuration
Configuration method:
    The standard use liquid is prepared by dilution of the standard stock solution (concentration of 1000 mg / L or 500 mg / L) for ion chromatographic analysis. Its accuracy directly affects the determination result. Therefore, it should use the national standard material center Standard stock solution to be formulated.
note:
The use of standard stock solution preparation of mixed use of liquid and dilution, to use the same specifications and calibration of the manufacturer's pipette, volumetric flask and so on. Standard stock solution and standard use liquid should be placed in polyethylene plastic bottles, stored in the refrigerator, removed from the refrigerator before use, stand still to room temperature.
Standard working curve preparation:
 The standard working curve should be drawn at least 4 points. The standard working curve can only be plotted in its linear range, and the correlation coefficient of the standard working curve is preferably greater than 0.9990. The standard working curve should be drawn at least 4 points from the standard solution concentration.
note:
 The standard curve should be reconstituted each time the reagent, column, suppressor and other fittings of the eluent should be replaced. The sample concentration of the standard curve can not exceed the linear range of the detector response value, preferably