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Biomedical subjects

B Caddy

Publications and source records attributed to B Caddy.

At least 19 recordsLinked to original sources
PubMed1997

Assessment of an automated immunoassay based on kinetic interaction of microparticles in solution for determination of opiates and cocaine metabolite in urine.

A recently introduced automated immunoassay which is based on kinetic interaction of microparticles in solution (Roche ONLINE), was evaluated for the detection of cocaine metabolite benzoylecgonine (BE) and opiates in human urine. Cross-reactivity for the opiates morphine (100%), codeine (88%), 6-monoacetylmorphine (88%), and morphine 3-glucuronide (72%) was assessed. Analytical recovery evaluated on blank urines spiked with 0, 250, 300, 350, and 500 micrograms/L of morphine and BE (n = 10), varied from 85.2 to 100.2% for opiates and from 81.4 to 93.1% for the cocaine metabolite. The within-day precision ranged from 1.4 to 4.7% for morphine and from 4.2 to 4.8% for BE. The repeatability of the standards over 1 month was 1.0-3.3% for opiates and 1.7-5.1% for BE, and thus allowing measurements to continue over 30 days without re-calibration. This method compared favourably with the SYVA EMIT d.a.u system and gas chromatography/mass spectroscopy (GC/MS) methods.

Autoanalysis↗
PubMed1996

High-performance liquid chromatographic analysis with fluorescence detection of ethyl centralite and 2,4- dinitrotoluene in gunshot residues after derivatization with 9-fluorenylmethylchloroformate.

A reversed-phase high-performance liquid chromatographic method using 9-fluorenylmethylchloroformate (FMOC) as fluorogenic labeling reagent for the detection of ethyl centralite (EC) and 2,4-dinitrotoluene (2,4-DNT) in gunshot residues is reported. Residues were sampled with cotton wool swabs which were then extracted and the extracts cleaned by TLC. The sample spots on the TLC plate were scraped off and extracted to recover the analytes. The extract corresponding to EC was hydrolyzed while 2,4-DNT was reduced. The hydrolysis and reduction products (N-ethylaniline and 2,4-diaminotoluene, respectively) were derivatized with FMOC in alkaline buffer solution at 52 degrees C for 20 min. The derivatives were analyzed by a reversed-phase HPLC with fluorescence detection. The detection limits for EC and 2,4-DNT were 200 pg and 1 ng per standard sample, respectively. Three out of eleven kinds of gunpowders analyzed were found to contain EC, while another three were found to contain 2,4-DNT. According to the results of gunpowder analysis, two different kinds of ammunition, which were presumed to contain EC in one and 2,4-DNT in the other, were chosen for test firings. Ethyl centralite was detected in cotton swabs sampled from spent cartridge cases of both of these two kinds of ammunition, but 2,4-DNT was not detected in any of these spent cases. Nine out of twelve samples swabbed from shooting hands at various times after firing two rounds of either kind of ammunition were found to contain EC, while none of these swabs were found to contain 2,4-DNT. The quantities of EC recovered from these hand swabs were shown to be in the range of 0.6 to 4.0 ng.

Chromatography, High Pressure Liquid↗
PubMed1986

Preparation of novel, curable capillary gas chromatographic systems and their application to the analysis of underivatized barbiturates and other controlled drugs of forensic interest.

Three novel stationary phases have been prepared for the analysis of underivatized barbiturates by incorporating different monomers, N,N'-di(but-3-enyl)amylobarbital, N,N'-di(pent-4-enyl)amylobarbital and N,N'-di(hex-5-enyl)amylobarbital into a standard SE-54 matrix. The chromatographic behaviour of these columns is compared with a standard immobilised SE-54 column. They are shown to be less polar than the previously reported N,N'-diallylamylobarbital incorporated column. Of the three new phases, the one incorporating the monomer N,N'-di(but-3-enyl)amylobarbital shows the best performance for the separation of a mixture containing 22 barbiturates but all are selective, very efficient, inert and can be used up to at least 300 degrees C. The versatility of these new phases is demonstrated further by the analysis of other drugs of abuse. They offer unique selectivities not previously available.

Barbiturates↗
PubMed1984

Mushroom toxins of the genus Cortinarius.

3 major components of the toxic fungus Cortinarius speciosissimus have been isolated and their structures determined as cyclic polypeptides. 2 of these compounds have been shown in laboratory animals to cause nephrotoxicity characteristic of Cortinarius mushroom poisoning.

Amino Acid Sequence↗