![]() Tailing Factor is calculated by following formula, The value of N depends upon the substance being chromatographed as well as the operating conditions, such as the flow rate and temperature of the mobile phase or carrier gas, the quality of the packing, the uniformity of the packing within the column, and, for capillary columns, the thickness of the stationary phase film and the internal diameter and length of the column. Where tR is the retention time of the substance, and W is the peak width at its base, obtained by extrapolating the relatively straight sides of the peak to the baseline. The Column Efficiency is measured by following formula, Replicate injections of a standard preparation are used to demonstrate the system performance when it gets exposed to some specified column usage, environment, and plumbing conditions. Data from five or six replicate injections are used if requirement of relative standard deviation is less than 2%. Where, tR2 and tR1 are retention times of two compounds, W2 and W1 are the corresponding widths at the bases of the peaks obtained by extrapolating the relatively straight sides of the peaks to the baseline. Resolution is calculated by following formula, For complex sample mixtures Rs should be determined for the critical pairs of components to characterize their separation. Resolution is a measure for the ratio of the distance of two adjacent peak maxima and their widths. Absolute retention times of a given compound may vary from one chromatogram to the next. Coincidence of retention times of a sample and a reference substance can be used as a partial criterion in construction of an identity profile but may not be sufficient on its own to establish identity. Chromatographic retention times are characteristic of the compounds they represent but are not unique. tR may be used as a parameter for identification. In liquid chromatography and gas chromatography, the retention time, tR, is defined as the time elapsed between the injection of the sample and the appearance of the maximum peak response of the eluted sample zone. There are some System suitability parameters which can be used to check the system before starting the sample analysis are listed below. ![]() System suitability testing limits are acceptance criteria that must met before starting the analysis. ![]() HPLC chromatographic technique is used in pharmaceutical industries for analysis. HPLC, short for High-performance liquid chromatography is a technique used for separating the components in a mixture. It is required to done before every sample analysis. System suitability is to prove that system is working perfectly before the analysis on HPLC, GC, TOC analyser or any other system. ![]()
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