Isomeric separation of methamphetamine by HPLC chiral column.

Methamphetamine and its active metabolite, amphetamine, are optically active compounds which, based upon synthetic routes, can be found in two forms; pure d-form and racemic mixture. Analysis of their isomers can help to identify which precursor is currently spreading widely in a given region. Since there are many drugs that can be metabolized to amphetamine/methamphetamine, isomeric separation can be a useful tool for evaluation of these drugs, as well. Indirect method by using N-trifluoroacetyl-1-prolyl chloride (1-TPC) was found to have limited accuracy due to the contribution effect. In this presentation a direct method using HPLC Chirex chiral column 3022 was studied. Although the method gave no base-line separation of two different isomer peaks, it gave good sensitivity, reliability, and linearity. No contribution effect was found in the method presented. It also gave excellent correlation with the 1-TPC method.

Urinary D-aminolevulinic acid in workers exposed to lead.

One hundred and fifty-five urine samples from workers in car painting, motor-bicycle or tricycle drivers, and printers were quantitatively analysed for delta-aminolevulinic acid. The levels were 0.86 + 0.32, 0.8 + 0.23 and 0.76 + 0.24 mg/dl, which were increased beyond normal levels by 63, 90 and 84 percent of the three respective worker groups.