dear fellow members, i seek your valuable advice on the following problem we are facing with our gas chromatograph (schimadzu make);model:2014 lately while performing tests for isomeric phenylethylamine on a chiral column , we observed that the Rete

dear fellow members, i seek your valuable advice on the following problem we are facing with our gas chromatograph (schimadzu make);model:2014 lately while performing tests for isomeric phenylethylamine on a chiral column , we observed that the Retention time and the Peak areas of the two isomers that is R & S -phenylethylamine has deviated. hence the following steps were carried out> 1.sample preparation was checked and new samples alongwith with standard samples were injected.HOWEVER NO IMPROVEMENT WAS OBSERVED THAT IS THE SYSTEM FAILED TO QUANTIFY 0.25% OF OTHER ISOMER IN THE PRODUCT. 2.LEAKAGES WERE CHECKED,HOWEVER NO LEAKAGES WERE FOUND. 3.AUTO FLOW CONTROLLER WAS CHECKED AND CALIBERATED,HOWEVER NO IMPROVEMENTS WERE OBSERVED. 4.GAS CYLINDERS AND FILTERS WERE CHANGED,HOWEVER NO IMPROVEMENTS WERE OBTAINED. please let me know your expert coments on the matter . regrds, janak gupta