PubMed Health⌕ Search

Biomedical subjects

Y H Caplan

Publications and source records attributed to Y H Caplan.

10 recordsLinked to original sources
PubMed1979

Detection of drugs using XAD-2 resin. I:Choice of resin, chromatographic conditions, and recovery studies.

Amberlite XAD-2, a nonionic polystyrene divinylbenzene resin, was first used for the analysis of drugs in urine and a number of reports have described the development at optimal conditions for extraction, including type of resin columns, pH conditions, and eluting solvents. XAD-4 and XAD-7 resins were compared to the similarly structured XAD-2 resin and no significant advantage over the XAD-2 resin for drug screening was observed. A quantity of 5 to 6 g of resin was found to have sufficient capacity for the extraction of 200 ml of pentobarbital solution (1 mg/100ml). A column flow rate of approximately 15 ml/min (gravitational flow) was sufficient for analysis and slower rates were not more efficient. A mixture of ethyl acetate and 1,2-dichloroethane (3:2) was found to give best overall recovery (66 to 94%) of drugs, the resulting extracts being reasonably free of interfering substances. A pH value of 8.5 is recommended as optimum for comprehensive analysis of acidic and basic drugs. Recovery studies were conducted on spiked samples to determine drug losses occuring during various steps in the XAD-2 extraction procedure for four acidic (amobarbital, secobarbital, pentobarbital, and phenobarbital) and four basic (morphine, codeine, meperidine, and methadone) drugs. A relatively small amount (0 to 5%) of the drugs was not adsorbed by the resin and amounts varying from 6 to 40% failed to be desorbed by the eluting solvent. Additional losses occurred during the removal and analysis of TLC spots. Recovery of drugs from aqueous solutions analyzed with the XAD-2 resin were compared to recoveries reported in the literature with other XAD-2 resin methods for the extraction of drugs from urine. Recovery of phenobarbital, morphine, and codeine improved by 4 to 23% while recoveries of amobarbital, pentobarbital, secobarbital, methadone, and meperidine were 4 to 28% less efficient when compared to literature data.

Barbiturates↗
PubMed1979

Detection of drugs using XAD-2 resin. II:Analysis of liver in medical examiner's cases.

Liver tends to concentrate drugs in quantities generally higher than those found in blood or other body compartments. This fact as well as the general availability of liver in postmortem cases makes it an important specimen for comprehensive toxicologic investigation. A scheme for the analysis of liver for drugs with tissue hydrolysis, XAD-2 resin extraction, and TLC has been developed and the parameters affecting recovery have been studied. The hydrolysis of liver specimens at various pH conditions resulted in an improved recovery for morphine by using pH 2 (2N hydrochloric acid). Recoveries of barbiturates, codeine, and meperidine were essentially the same at pH 2 and pH 3. A considerable loss (22 to 55%) was observed for four drugs (pentobarbital, morphine, codeine, and meperidine) as a result of drug binding to the tissue pellets during the process of centrifuging the liver homogenates. This method is recommended as a comprehensive screening procedure for drugs in liver tissue. For quantitative purposes, however, it is necessary to determine a correction factor for all the losses occurring at the various steps of the procedure. This procedure compared favorably with other procedures for liver analysis reported in literature.

Barbiturates↗
PubMed1979

Detection of drugs using XAD-2 resin. III:A routine screening procedure for bile.

The ability of bile to concentrate drugs and metabolites coupled with its general availability make it suitable for analysis and often the fluid of choice in postmorten cases requiring drug screening. Bile (5 to 10 ml) was diluted with water, sulfuric acid was added, and the mixture was autoclaved. The precipitated bile salts were easily removed by filtration and the filtrate (pH adjusted to 8.0 to 8.5) extracted with XAD-2 resin. Drugs were eluted with a mixture of ethyl acetate/1,2-dichloroethane and analyzed with thin-layer chromatography. Varying the dilution of bile improved the recovery of morphine, codeine, methadone, amobarbital, and phenobarbital. Excessive dilution, however, caused a washing phenomenon and reduced recovery of some drugs, as shown with morphine and codeine. The procedure described is useful for the rapid screening of bile specimens for drugs.

Barbiturates↗
PubMed1976

1,1,1-trichloroethane: report of a fatal intoxication.

TCE was indicated in the accidental death of a woman cleaning up a paint spill in an enclosed, poorly ventilated room. Blood and tissue concentrations of TCE were measured by head-space gas chromatography. The concentrations found were compared with previously reported concentrations concluding that the demonstrable presence of TCE in blood at a concentration above 1.0 to 1.5 mg/100 ml would be consistent with death. However, the rapid dissipation of TCE from blood dictates that its presence in post mortem samples at any concentration must be considered as a factor in determining the cause of death.

Adult↗
PubMed1975

Alcohol intoxication and serum osmolality.

The relation between serum osmolality and blood-alcohol was studied prospectively in 565 acute trauma patients. The two measurements were closely correlated. It is therefore possible to estimate the blood-alcohol from serum osmolality to assist in the clinical management of acutely injured patients.

Accidents↗
PubMedDate not supplied

Concentration of cocaine and metabolites in plasma of humans following intravenous administration and smoking of cocaine.

Plasma was obtained from 10 human subjects at various intervals after administration of two rapid doses of cocaine, either intravenously or by smoking, and multiple doses by smoking and intravenously. The plasma was analyzed for COC and its metabolites, benzoylecgonine (BE) and ecgonine methyl ester (EME). Plasma concentrations of COC were found to be dose-dependent. For patients receiving two successive doses of COC intravenously (IV) or by smoking (SM), the average half-life of COC was found to be between 38 and 39 minutes, regardless of the dose or route of administration. Considerable interindividual variation was observed. Multiple doses of both SM and IV COC were administered to three patients in a manner consistent with COC abuse. The maximum COC concentration observed was 1.2 mg/L following a total administration of 316 mg of COC over 90 min. Analysis of BE and EME confirmed that BE is the principle metabolite of COC in blood. All COC was accounted for by BE. EME, when present, did not exceed 5% of the BE concentration.

Cocaine↗
PubMedDate not supplied

The role of ecgonine methyl ester in the interpretation of cocaine concentrations in postmortem blood.

A study of the metabolism of in vivo cocaine (COC) and the stability of in vitro COC suggests that the presence of benzoylecgonine (BE) in unpreserved blood arises from in vivo COC metabolism and that ecgonine methyl ester (EME) in unpreserved blood arises from in vitro COC hydrolysis. Postmortem cases positive for COC were studied to determine if molar concentrations of EME in unpreserved blood could be used to estimate the blood COC concentration at the time of death when added to the molar COC concentrations. COC was analyzed in 10 postmortem blood specimens between 1 and 8 days following death and again 10 to 70 days after further storage. The COC lost was accounted for by its hydrolysis to EME. Good correlation (r = 0.9677, p < 0.001) was observed when the blood COC concentrations in postmortem cases were compared to blood COC concentrations predicted by the addition of blood COC and EME concentrations; hence, analysis for EME and estimation of perimortem COC concentrations can assist in defining deaths associated with COC use.

Adolescent↗
PubMedDate not supplied

Detection of cocaine and its metabolites in human amniotic fluid.

The dramatic rise in maternal drug abuse and the incidence of positive drug findings during neonatal testing has increased the need for prenatal toxicological testing for drugs of abuse. Human amniotic fluid samples collected after 13-39 weeks of pregnancy were screened for cocaine metabolite (benzoylecgonine) by fluorescence polarization immunoassay (FPIA). All positive samples, as well as any accompanying maternal serum, were confirmed by gas chromatography/mass spectrometry (GC/MS) for cocaine and its metabolites. Five samples out of 450 were positive for cocaine, benzoylecgonine, and ecgonine methyl ester by GC/MS. In addition, one sample was also positive for cocaethylene. Two maternal serum samples were positive for benzoylecgonine and ecgonine methyl ester. The presence of cocaine, benzoylecgonine, ecgonine methyl ester, and cocaethylene in the amniotic fluid suggests that the fetus is exposed to cocaine and its metabolites through maternal circulation. The impact of this exposure on the health of the newborn is unknown.

Amniotic Fluid↗
PubMedDate not supplied

Serial capillary gas chromatography/Fourier transform infrared spectrometry/mass spectrometry (GC/IR/MS): qualitative and quantitative analysis of amphetamine, methamphetamine, and related analogues in human urine.

A method using serial capillary gas chromatography/Fourier transform infrared spectroscopy/mass spectrometry (GC/IR/MS) for the analysis of derivatized amphetamine, methamphetamine, and related analogues was developed. The GC/IR/MS was configured and optimized with a Hewlett-Packard (HP) 5890A gas chromatograph with a 12-m x 0.32-mm i.d. HP-5 capillary column serially interfaced through an HP 5965A infrared detector to an HP 5970 mass selective detector with a fused-silica 1.2-m x 0.10-mm i.d. column. Urine samples are extracted and derivatized as heptafluorobutyryl (HFBA) derivatives. For quantitation GC/MS in the selected ion monitoring (SIM) mode was used, with D,L-amphetamine-D5 as the internal standard. Gas chromatography/Fourier transform infrared spectrometry (GC/FT-IR) quantitation uses a selected wavelength chromatogram, spectral subtraction, double internal standard method using both D,L-amphetamine-D5 and 4-phenyl butylamine. Sensitivity for the combined GC/MS and GC/FT-IR system for amphetamine and methamphetamine shows limits of linearity of 100 to 5000 ng/mL, a limit of detection of 25 ng/mL, and a limit of quantitation of 98 ng/mL. The overall recovery for amphetamine and related analogues was greater than 85%. Precision studies for concentrations over the range of 200 to 1500 ng/mL showed coefficients of variations ranging from 2.8 to 13.0%. Correlation studies for quantitative GC/MS SIM and GC/FT-IR are greater than 0.98 for amphetamine, methamphetamine, and related analogues. Each analysis includes GC/MS SIM and GC/FT-IR quantitation, qualitative nonselective full spectra GC/FT-IR, and GC/MS scans of HFBA derivatives cross-referenced with an internal drug library, which provides high confidence and a means for the surveillance of amphetamine-like chemical analogues.

Amphetamine↗