Basic parameters of methods and standard solutions (SS)
- The following chromatographic methods are used to analyze alcohol-containing products: external standard method using a set of standard solutions (SS), traditional internal standard method using an additional substance added to the SS and product samples at a known concentration, and new modified internal standard method (IS_Ethanol), in which ethanol contained in the SS and products is used as an internal standard.
- All methods use multiple SS containing compounds in known concentrations. Each set of SS corresponds to several concentration levels, which are needed for determination of the calibration coefficients and verification the linearity of the detector response. It is necessary to specify the count of analyte compounds (uncluding ethanol) and the count of SS to work of the calculator.
- Different methods of alcohol analysis may use different units of concentration measurement. To ensure accurate calculations and easy comparison of different methods, concentration values are converted from "primary" units of measurement to "final" units, which will be used in the calculations in the methods.
- To calibrate a chromatograph using methods that use an internal standard (traditional method or IS_Ethanol), the relative response factors (RRFs) are determined. A single calibration level is used as a rule with an "intermediate" concentration values. The remaining levels are used to evaluate the linearity of the detector response.