Athletes Test Positive for Morphine.

Three collegiate athletes tested positive for morphine after a championship competition; however, all three denied narcotic use. The medical team was stumped until the coach suggested a food source. Reviewing the literature and recreating the scenario helped identify the cause.

Application of a novel form of solid-phase sorbent (Empore membrane) to the isolation of tricyclic antidepressant drugs from blood.

We employed a new form of solid-phase material, the Empore octyl (C8) extraction membrane (SPEM), for the efficient extraction of tricyclic drugs from patients' serum specimens. Both extraction and companion high-performance liquid chromatographic (HPLC) assay of doxepin (DOX), desmethyldoxepin (DDOX), imipramine (IMI), desmethylimipramine (DESI), amitriptyline (AMI), nortriptyline (NOR), clomipramine (CLO), and desmethylchlomipramine (DCLO) are presented here. Routinely, serum (1.0 mL or less) adjusted to pH 5.5 with phosphate buffer is passed through the SPEM secured in a MF-1 microfilter unit. Proteins and potential interferences retained on SPEM are removed with an acetonitrile-water wash. The tricyclic drugs are eluted with HPLC mobile phase and the eluate is injected directly on a Zorbax cyanopropyl (CN) HPLC column, thereby avoiding time consuming evaporation-concentration steps that can affect drug stability. Recovery for all drugs exceeds 90% and analytical responses are linear from a lower limit of sensitivity of 8 micrograms/L up to at least 1000 micrograms/L. Between-run coefficients of variation (CV) range from 2.9 to 8.3% through the concentration range of 75 to 300 micrograms/L. Performance characteristics of the SPEM are compared to those of conventional large particle silica- and polymeric-based sorbents. Within the requirements of this assay, the SPEM extraction requires less sample volume and reduces elution and solvent volumes.

Seasonal arsenic exposure from burning chromium-copper-arsenate-treated wood.

All eight members of a rural Wisconsin family experienced recurring neurological and medical illness over three years, especially during the winter months. Arsenic, in concentrations of 12 to 87 ppm, was noted in the hair of the mother and father, and analysis of hair and fingernails of all family members demonstrated pathological levels of arsenic. For four years the five-room home had been heated with a small wood stove in which outdoor or marine plywood and wood remnants had been preferentially burned. Stove ashes that contained more than 1,000 ppm of arsenic contaminated the living area, and the ratio of copper, chromium, and arsenic pentoxide in this ash matched the ratio used in the chromium-copper-arsenate-treated wood.

Enzymatic immunoassay vs. gas/liquid chromatography for determination of phenobarbital and diphenylhydantoin in serum.

The antiepileptic drugs diphenylhydantoin and phenobarbital were measured in serum by a new commercially available enzyme immunoassay procedure ("EMIT," Syva Corp.). The procedure requires less than 5 min and no more than 50 mul of serum per determination. It is simple; only four steps (pipetting and diluting with an automatic pipettor-dilutor) are required before spectrophotometry. Twenty replicate analyses of a serum containing phenobarbital and diphenylhydantoin gave results with a CV of 6.8% and 9.1%, respectively. Results attained in a large series of patients were compared with results by a gas/liquid chromatographic procedure. For phenobarbital r = 0.97, and for diphenylhydantoin r = 0.98. No false negatives or false positives were encountered.