Question

answer the following question related to GC ethanol determination. you own words for life saving rating *****

1) Which method of determining the % alcohol peak area or height should be better and why?

2) why is it acceptable for the internal standard to be V/V% instead of M/V%?

Answer 1

Question 1

The peak area should always be used to determine the % of weight. This is beacuse a compound present in large abundance might elute from the column over a long time resulting in a wide but short peak (scenario 1). The peak area is large in this case, which corresponds to the amount of substance, where as the peak height is small, which corresponds to te rate of elution. Similarly a substance present in small amounts may elute in a shorter time resulting in a tall peak and very narrow (Scenario 2). Therefore, it is always better to use the area rather than the height ofthe peak.