Important issues in urinary drug testing are the variability between consecutive urine specimens, the duration of positive specimens after last intake, and the usefulness of @entity1011 concentration to correct for variability in urine concentration. These issues were addressed in the present study with @entity4944 as the drug of abuse. Drug users who were starting their sentences in prison participated in the study. Urine specimens were collected 1 to 5 times per day. Screening was performed by EMIT d.a.u. (cutoff, 0.30 microgram/mL) and EMIT II (cutoff, 1.00 microgram/mL), and confirmation was performed with gas chromatography-mass spectrometry. @entity1011 and pH were recorded. @entity4944 was demonstrated in seven subjects. The highest concentration was 135 micrograms/mL. The last positive-screened specimen was observed by EMIT d.a.u. after almost 9 days of imprisonment and by EMIT II after 3 days. Large concentration differences could be found between consecutive specimens, accompanied by considerable differences in @entity1011 and pH. The individual curves were generally smoother after @entity1011 correction of concentrations. As expected, urinary pH was observed to influence the excretion.

Urinary excretion of XXXX after termination of drug abuse.

@entity1011 :: ('MESH:D003404', 'Chemical') :: ['creatinine', 'Creatinine'] @entity4944 :: ('MESH:D000661', 'Chemical') :: ['amphetamine', 'Amphetamine']
@entity4944 :: (MESH:D000661,Chemical) :: ['amphetamine']
