Question

I am developing a GC method for the analysis of pharmaceuticals in ground water. What figures of merit should I use to evaluate the chromatographic performance of a method? Give names and a brief description of what they are / how they are determined.

Answer 1

Development of GC method

Analysis of ground water sample for pharmaceuticals as analgesics such as naproxen, etc. can be done by employing GC as a tool. In the analysis, first the water sample is diluted with enough water to make a stock solution. The pure standards of possible drugs are then made and added to the water stock solution. The pure sample solutions of drugs and the solution of ground water + drug are then injected into the GC. The injection temperature is kept high enough so that all of the samples gets evaporated. The column temperature and rate of increase in temperature is maintained to a minimum. The run time is taken such that all the components comes out of column. The retention times of pure sample are calculated and then are compared with th retention times of mixture. The total area is calculated. The concentration of drug in the water sample is then calculated by internal standard addition method. Detector used is UV-Vis and Mass for correctly identifying the components.