Drug-testing methods and reliability.

The methods used by laboratories to analyze urine collected from employees are described. Federally designed procedures designed for analyzing government employee samples have become the highest standard for performing such tests, although at present there are no guidelines that specifically address drug testing in the private sector. Samples and analysis should be handled in a manner that ensures that test results are legally defensible.

Testing for basic drugs in biological fluids by solvent extraction and dual capillary GC/NPD.

Basic drugs were extracted from 1 mL of serum, urine, or other biological fluids under alkaline conditions into hexane:isoamyl alcohol (98:2). The drugs were back-extracted into acid and re-extracted into 50 microL of chloroform:isoamyl alcohol (95:5) after the acid had been alkalinized. An aliquot of the chloroform:isoamyl alcohol was injected onto a temperature programmed gas chromatograph equipped with two nitrogen phosphorus detectors and two fused silica capillary columns fitted into a single injector.

Adsorbent and cathartic inhibition of enteral drug absorption.

The effects on absorption of drugs given by mouth of adsorbents (charcoals and resins) and cathartics (osmotic and oil) were studied in vitro and in vivo using acetaminophen (paracetamol) as a test drug. In vitro adsorption isotherms were measured at 37 degrees C in simulated gastric and gastric plus intestinal juices. Maximum binding capacity (MBC) of 16 charcoals and resins varied 30-fold, from 0.

High pressure liquid chromatography for simultaneous analysis of anticonvulsants: comparison with EMIT system.

We present a new high pressure liquid chromatography (HPLC) method for the simultaneous analysis of primidone, phenobarbital, phenytoin, and carbamazepine in serum. The chromatographic separation is carried out using an Altex model 110-A pump, a 250 times 4.6 mm column containing 5 mum Spherisorb ODS particles and a variable wavelength ultraviolet detector set at 197 nm.