Drug and chemical blood-level data 2001

Current blood-level data are presented for drugs and chemicals of toxicologic interest. The data represent an update of previously published compilations of therapeutic, toxic and lethal blood-levels.

Chemical burn from alkaline batteries--a case report

A 2-year-old male was found to have a third degree (full thickness) burn on his rear right thigh. The father discovered the burn at a physician's office where the child was being treated for an ear infection. The physician notified authorities of suspected physical child abuse.

Drowning due to cyclobenzaprine and ethanol

The deceased was a 35 year old female who was found by her husband in the bathtub with her head and face submerged in the water. Autopsy findings were unremarkable. Toxicological analysis revealed the presence of ethanol (215 mg/dL) and cyclobenzaprine (1.786 mg/l) in the blood. This high concentration of cyclobenzaprine (Flexeril) in combination with alcohol proved to be fatal.

Heroin fatality due to penile injection

Death due to heroin overdose and/or rapid injection of heroin is a frequent occurrence among opioid addicts. We present an unusual case of heroin fatality due to the injection of the drug in the penis. Blood, urine, bile, and vitreous humor concentrations of morphine were 0.68, 0.49, 0.32 and 0.062 microg/ml, respectively. Ethanol was detected at concentrations of 104, 124, 106, and 94 mg/dl in the blood, urine, bile, and vitreous humor, respectively. The cause of death was determined to be due to heroin and ethanol intoxication.

Fatal inhalation of 1,1,1-trichloroethane

A 13-year-old male was found dead in the woods subsequent to 1,1,1-trichloroethane (TCE) inhalation. Autopsy findings included tissue congestion of lung, liver and kidney. Certain precautions were taken in collecting and storing biological samples in order to prevent loss of TCE by evaporation. The availability of volatile solvents coupled with the increase of volatile substance abuse makes it easy for abusers to obtain.

Extraction of selected drugs from serum using microwave irradiation

Microwave irradiation is used as an alternative heating method for extraction over more conventional hot plate methods. We describe a fast, efficient method for the determination of selected drugs in human blood/serum using microwave extraction. The microwave extraction of organic substances requires special instrumentation and the results have been compared with the results from classical liquid/liquid extraction. The present microwave extractions were performed in an 'atmospheric pressure' system. Before irradiation with microwaves, an appropriate solvent mixture was added to the buffered specimen. Lidocaine, methadone, diazepam, nordiazepam, propoxyphene and norpropoxyphene were tested as model substances. The quantitation was performed by GC/NPD. The procedure has been applied successfully to a number of forensic cases. The use of microwaves decreases the time of extraction and the solvent consumption.

The effect of storage at various temperatures on blood alcohol concentration

There is a paucity of data available on the effect of storage on blood alcohol concentration (BAC) at elevated temperatures. Changes in serum alcohol concentration (SAC) and BAC were studied. Serum samples spiked with alcohol in the presence or absence of preservative were stored at 26.7 degrees, 32.2 degrees or 37.8 degrees C respectively. Serum alcohol concentrations were determined daily on days 1 through 14, and on days 21 and 35. Under these controlled conditions, no significant change in SAC was observed at the aforementioned temperatures. Whole blood samples submitted from outside agencies were initially analyzed (day 1), then stored for 35 days at different elevated temperatures before a second analysis. The average loss in BAC was 19.20 +/- 15.6, 9.95 +/- 5.7, and 15.60 +/- 6.9% when the samples were stored at 26.7, 32.2 and 37.8 degrees C, respectively. The alcohol loss from whole blood samples may be attributed to chemical oxidation rather than to elevated temperatures. It is, therefore, concluded that a whole blood sample obtained from a living individual and stored in a locker, glove compartment or other environment where the temperature is elevated, may lose 10-19% of its alcohol content over 35 days of storage. On the other hand, when a serum or plasma sample is exposed to the same environment, no significant change in SAC was observed. The utility of this information is significant to the forensic toxicologist. The results of this study suggest that a whole blood sample analyzed after exposure to elevated temperature may have had, originally, a higher BAC.

Acute overdose of zolpidem

Zolpidem (Ambien) is an imidazopyridine hypnotic recently introduced in the USA. We report a case of a fatal overdose of Ambien. A 68-year-old female ingested at least 30 tablets of 10 mg Ambien (300 mg). She was found dead at home. Toxicological analyses revealed blood concentration of 4.1, 19.3 and 2.3 micrograms/ml of zolpidem, meprobamate and carisoprodol, respectively.

Determination of absorption time of ethanol in social drinkers

This study was designed to determine the peak, plateau and absorption times of ethanol in a social drinking setting. For the purpose of this study, subjects who had drinking times of 30 min or greater were considered to fit the 'social drinking' category. Healthy subjects (31 male and two female) were tested immediately after they finished drinking. Blood alcohol concentrations (BACs) were measured using a breath testing instrument (Intoxilyzer 5000). Drinking time, type and volume of alcoholic beverage consumed, subject's weight, and a brief description of the breakfast meal were recorded for each subject. The peak, plateau and absorption times were determined for each subject. Peak time was the time interval between the end of drinking and the maximum blood alcohol measurement. Plateau time was the time interval between peak time and the end of absorption time, i.e. the interval between peak time and the beginning of dissipation. Absorption time was defined as the peak time plus plateau time. Among 31 subjects with drinking times of 30 min or greater, 23 (74.2%) had peak and absorption times of < 30 and < 60 min, respectively. Twenty four out of 31 (77.4%) social drinkers had an absorption time of < 60 min, regardless of their peak time. Overall, the average peak and absorption times were 17.4 +/- 17.3 (range 0-74) and 42.2 +/- 31.5 (range 1-130) min. Plateau times averaged 24.9 +/- 23.1 with a range of 0-74 min. It can be concluded from this study that in a social drinking setting, a shorter time to peak and faster rate of absorption may occur when ethanol is consumed over an extended period of time. This is in contrast to results reported in earlier studies involving bolus drinking, where longer absorption times occurred.

Ingestion of lye

This paper reports on the case of a 13-year-old white male who committed suicide by ingestion of heavy duty drain and sewer opener. He left behind a note indicating his suicide. This teenager was grieving over the suicide of one of his friends and was under counseling by a mental health therapist at school. Results of autopsy and toxicological analyses indicated the ingestion of a highly alkaline substance that is consistent with the ingredients of the drain opener mentioned.

Accidental death by nitrous oxide inhalation

Nitrous oxide is a popular inhalation anesthetic-analgesic agent. Its euphoric action and its availability have led to its abuse. We report a case of fatal accidental asphyxia due to nitrous oxide abuse. The deceased was a hospital worker who had access to the hospital supply of nitrous oxide. His death was due to hypoxemia and asphyxiation, secondary to nitrous oxide inhalation.

The role of trauma in postmortem blood alcohol determination

In postmortem cases, a blood sample is frequently obtained by transthoracic (TT) puncture. The purpose of this study was to determine if, in traumatic death, blood samples collected by TT provided a valid sample for blood alcohol analysis. A retrospective study (1980-1986) was conducted to evaluate possible contamination of blood by GI alcohol in traumatic death cases. Out of 6000 cases reviewed, 19 cses with BACs > 500 mg/dl were found and 8 of these cases involved traumatic death with GI laceration and/or transection. The results of this study support the hypothesis that blood samples from the 8 cases had been contaminated, resulting in a falsely elevated BAC. A transthoracic study (1987-1989) was conducted under controlled conditions, where blood alcohol content of TT blood samples was compared with samples collected from the intact heart chamber. Seven out of 28 cases of traumatic injury revealed trauma to the GI tract. The results showed that when GI traumatic injury occurs and unabsorbed ethanol is present in the stomach, contamination of TT blood samples occurs and artificially elevated BACs are obtained. It is recommended that, in cases of traumatic injury, heart blood samples from the intact heart chamber, as well as samples of additional biological fluids, be collected to rule out the possibility of contamination and to ensure that the BAC used for forensic interpretation is accurate.

The study of tricyclic antidepressants in formalin-fixed human liver and formalin solutions

The stability of amitriptyline, nortriptyline, desipramine and imipramine in formalin-fixed human liver tissue and formalin solutions was investigated. The levels of the tricyclic and its primary demethylated metabolite in the frozen liver were determined and compared with levels obtained in the formalin-fixed liver and formalin solutions in which the liver was stored. It was obvious that some methylation of the secondary amine, nortriptyline, to the corresponding tertiary amine, amitriptyline, and of desipramine to imipramine took place in the formalin environment. Nortriptyline was not detected in most cases, suggesting that it may degrade more rapidly than desipramine. There was no consistent ratio between the concentration of the drug in the frozen liver tissue versus formalin-preserved tissue or versus formalin solution. The methylation rates of the secondary amines could not be quantitated. Storage of the liver tissue in formalin at room temperature resulted in leaching of the drugs into the formalin solution. The drugs tested may be detected for up to 22 months in the formalin-fixed liver and in the formalin medium.

Blood versus synovial fluid ethanol concentrations in humans

Many tissues have been analyzed for their relevance in prediction of blood ethanol concentrations, with varying results. Synovial fluid is contained and protected by the bursa sac. Because of its high water content, it may be a suitable biological fluid for analysis if a linear correlation could be established between blood and synovial fluid ethanol concentrations. Blood-synovial fluid ratios of ethanol in 28 human cadavers, using an internal standard, exhibit a good distribution ratio with an average of 0.99 +/- 0.29 and a correlation coefficient of 0.89. This study shows that synovial fluid is a good alternative biological sample for prediction of blood ethanol levels within a range.

Interference of herbal drinks with urinalysis for drugs of abuse

Recently there have been claims among drug users that some herbal drinks interfere with urinalysis for drugs of abuse and yield false positive results. Proof of such claims has yet to be shown. Screening for drugs of abuse is usually carried out using fluorescence polarization immunoassay (FPIA) or thin-layer chromatography (TLC). Fifty herbal samples which are considered among the most purchased herbs in the consumer market were used to investigate such claims. The drug groups that were tested for included amphetamines, opiates, barbiturates, cocaine metabolite, methadone, and their analogs. The herbs were analyzed at different concentrations (0.1, 1, 3, and 5 g/100 mL of distilled water) using TLC and FPIA to determine if any interfere with urinalysis for drugs of abuse and yield false positive results. For the FPIA test, the sample infusions were analyzed directly using the automated ADX analyzer (Abbott Laboratory). For TLC, infusions of the herbs were added to a solid-phase extraction column (pH 9.25), then extracted with a methylene chloride-isopropanol solvent system. At this pH, neutral, basic, and acidic drugs of abuse are extractable. The developed chromatographic plates were sprayed sequentially with several reagents. None of the herbs in the concentration ranges screened showed any interference with TLC or FPIA, indicating the invalidity of such claims.

The use of bone marrow in the study of postmortem redistribution of nortriptyline

Thirty-two New Zealand Albino rabbits (1.5-2.0 kg) were dosed on a daily basis with 20 mg/kg nortriptyline (NT) prior to feeding for a period of five days. On the fifth day of dosing, the animals were sacrificed approximately 1.5 h after the final dose. A comparison was made of nortriptyline concentrations in the blood and bone marrow at the time of sacrifice, and between bone marrow collected at the time of sacrifice and bone marrow collected at 2, 4, 6, 12, 24, 36, and 48 h after sacrifice. The results indicate that a linear relationship exists between blood and bone marrow NT concentrations, with an average marrow-to-blood ratio of 29.98 +/- 3.91 and a correlation coefficient of 0.956. Additionally, there was no significant difference (p > 0.05) observed between NT concentrations in bone marrow at the time of sacrifice and its concentration up to 24 h after sacrifice. The results indicate that bone marrow may be used to predict blood concentrations of NT up to 24 h after death when a suitable blood sample is not available.

An outbreak of designer drug--related deaths in Pennsylvania

3-Methylfentanyl ("China White") is a "designer" opiate that has caused more than 100 overdose deaths in California since 1979, but that has not been associated previously with deaths east of the Rocky Mountains. During 1988, 3-methylfentanyl was identified in 16 fatal overdose cases in Allegheny County, Pennsylvania, contributing to a fourfold rise in overdose mortality during October of that year. Morphine was detected in the blood of five persons (31%) and cocaine in the blood of three persons (19%) dying of 3-methylfentanyl overdoses; these were demographically similar to 99 other fatal overdose cases investigated by the county coroner from 1986 through 1988. This documents the contribution of 3-methylfentanyl to overdose mortality in an eastern city and the use of 3-methylfentanyl with other illegal drugs. Drug abusers in the northeastern United States should be considered at risk for more "designer drug" overdose outbreaks in the future.

Plasma versus bone marrow desipramine: a comparative study

Correlation between plasma and bone marrow tricyclic antidepressants has not been studied before. Two groups of rabbits were given 10 and 20 mg of desipramine/kg body weight, respectively. Desipramine was administered to the animals once daily by mouth for 5 days. On the fifth day the animals were sacrificed and blood and bone marrow samples were collected and analyzed using a high performance liquid chromatographic (HPLC) method. Data showed that a correlation exists between bone marrow and blood desipramine. The bone marrow desipramine concentration increased as its blood levels increased. The average ratio of bone marrow to blood desipramine +/- S.D. (standard deviation) in both dosage groups was 37.2 +/- 4.46 with a range of 30.99-44.82. This investigation is promising and shows that bone marrow could be used as an alternative tissue in the absence of a suitable blood sample.

Sudden death following accidental ingestion of chlormequat

A 59-year-old white male accidentally ingested a mouthful of a plant growth chemical, Cycocel, containing 11.8% of the active ingredient (2-chloroethyl)trimethylammonium chloride (chlormequat). He was seen by a family physician and then transferred to a hospital where he died as a result of ventricular fibrillation, which progressed to asystole. Postingestion symptoms were typical of cholinergic crisis and included salivation, diaphoresis, bradycardia, visual disturbances, and seizure. Autopsy findings showed marked pulmonary edema, coronary atherosclerosis, atheromata of aorta, and localized adenocarcinoma of the prostate. Toxicological analyses of biological samples showed the presence of chlormequat in the stomach contents and urine.

The stability of several compounds in formalin fixed tissues and formalin-blood solutions

Buffered formalin solutions were added to spiked blood samples containing diazepam, phenytoin, carbon monoxide and cyanide to give formalin-whole blood solutions of 5 and 8%. Sections of liver positive for desipramine, phenobarbital and phenytoin were placed in separate 5 and 8% formalin-water solutions. The formalin-blood solutions were monitored daily for 30 days, while the fixed liver and formalin-water samples were analyzed once a week for 4 weeks. In the formalin-blood solutions losses were found for diazepam and phenytoin over the 30-day period of at least 41% and 33%, respectively. Cyanide detection was not possible immediately after the addition of formalin and the presence of carboxyhemoglobin was difficult to detect after 1 week. In the liver, losses of phenobarbital and desipramine were greater than 60% while phenytoin showed little change. This study has revealed that the drugs examined at toxic concentrations can be detected, with variable recoveries, for up to 30 days after fixation with formalin. However, quantitative analysis for cyanide and carboxyhemoglobin may be significantly impaired in the presence of formaldehyde.

Body distribution of ethchlorvynol

Ethchlorvynol (Placidyl) is a nonbarbiturate sedative hypnotic. Two fatal cases of ethchlorvynol overdose are reported. Toxicological analyses of body fluids and tissues were performed by gas chromatography using a flame-ionization detector. The quantitative method was sensitive and reproducible. Body distribution of ethchlorvynol in blood and other tissues is presented. Biological samples analyzed included blood, urine, bile, liver, kidney, eye fluid, and gastric contents. Results presented add to the pharmacokinetic data needed to study the disposition of drugs in different tissues. Findings in present two cases are compared with published toxicological data.

Determination of ethchlorvynol in body tissues and fluids after embalmment

A 54 year-old female expired at her residence. Her husband, a physician, signed a certificate stating that her death was due to cerebrovascular accident (CVA) and released her body to a funeral home, where she was embalmed. Since the deceased had a long history of medical problems and drug abuse, an autopsy was performed and no evidence of CVA was found. Toxicological analyses of body fluids and tissues revealed the presence of ethchlorvynol in high concentration in the bile (112 mg/l). The bloody fluid collected from the heart contained a concentration of ethchlorvynol below the limit for quantitation. Other findings included phenobarbital (32.8 mg/l) in heart bloody fluid and methanol (an ingredient of embalming fluid). The significance of the findings is discussed in relation to embalmment prior to autopsy and toxicological analyses. Ethchlorvynol concentration in the bile is compared to other fatal cases due to ethchlorvynol overdose.

Comparison of plasma, serum, and whole blood ethanol concentrations

The differences in ethanol concentrations, as measured by direct injection gas chromatography, among plasma, serum, and whole blood from living human subjects are examined. The samples containing serum and the corresponding ones containing whole blood arrived at the laboratory as part of the same submission. The ratio of the concentration of ethanol in serum to that in plasma is 1.00 +/- 0.01:1 with a range of 0.98:1 to 1.04:1. The serum/whole blood ratio and plasma/whole blood ratio are both 1.12 +/- 0.02:1. The former has a range of 1.09:1 to 1.18:1 and the latter ranges from 1.09:1 to 1.17:1.

An unusually high blood cocaine concentration in a fatal case

A fatal case resulting in an unusually high blood cocaine concentration is reported. Cocaine was administered intranasally, then orally. Blood concentrations of cocaine and the combination of cocaine and its metabolites were 51.7 and 85.0 mg/L, respectively. Case history, pathological findings, and tissue distribution of cocaine and its metabolites are presented.

Fatal strychnine ingestion

A postmortem case involving ingestion of a strychnine-containing preparation is reported. Strychnine levels were determined in blood, urine, bile, liver, kidney, stomach contents, small and large intestines, and brain. The procedure, which is sensitive and specific, employs a gas-liquid chromatograph equipped with a flame ionization detector (FID). The extraction procedure using 5 mL of body fluids or tissue homogenate is described in detail. This is the first strychnine mortality in Allegheny County within a period of 20 years.

Caffeine fatality: a case report

A case of fatal caffeine toxicity due to suicidal ingestion of a "look-alike" illicit drug is reported. Caffeine concentrations were determined by high pressure liquid chromatography (HPLC) with the brain having the highest level reported in the literature to date. Also, the blood concentration of caffeine was one of the highest among the cases reported. A literature review of caffeine fatalities is presented.

Blood versus bone marrow pentobarbital concentrations

Postmortem pentobarbital levels in rabbit heart blood and bone marrow were determined and compared. The average ratio of femur marrow/blood pentobarbital concentrations in 24 rabbits was 1.06 +/- 0.05. The average percent difference between actual plasma pentobarbital concentrations and calculated plasma pentobarbital concentrations was 5.82 +/- 1.96. Concentrations were determined by gas chromatography of extracted, derivatized pentobarbital.

Amoxapine fatalities: three case studies

Amoxapine (Asendin), a recently introduced dibenzoxazepine, has been effective in clinical studies for the treatment of various types of depression. Three amoxapine-related deaths are reported. Quantitation of amoxapine was carried out by gas chromatography using 3% OV-17 column. Blood amoxapine concentrations were 11.5 mg/l, 2.8 mg/l, and 0.89 mg/l. The concentrations are many-fold higher than the reported therapeutic serum concentrations of 0.21 mg/l. These cases illustrate the potential toxicity and lethality of amoxapine overdose and the need for caution in prescribing a large amount of amoxapine to patients with suicidal tendencies.

The unreliability of using a urine ethanol concentration to predict a blood ethanol concentration

Of approximately 5,000 forensic cases with a positive ethanol result, over 1,000 were available in which both blood and urine were present for comparison of ethanol content. Data were examined for calculation of the urine to blood ethanol concentration ratio, with the intent of evaluating the validity of predicting a blood ethanol level given a urine ethanol level. The overall urine to blood ethanol concentration ratio was 1.57:1 with a range of 0.7 to 21.0:1. The extremely wide range of values implies that a large degree of error would be introduced if a mean ratio was used when predicting a blood ethanol level from a urine ethanol level.

The rate and kinetic order of ethanol elimination

The rate and kinetic order of ethanol elimination was evaluated in human volunteers. Part I of the study involved dosing individuals with alcoholic beverages on two separate occasions. Breathalyzer tests were performed at 15-min intervals for a period of 5 h. Attention was focused on values obtained after peak blood ethanol levels had been reached. The second part of the study included having samples drawn from alcoholics at predetermined intervals during recovery from alcoholic intoxication. Blood ethanol concentration data was analyzed for kinetic order and a comparison of ethanol elimination rates of alcoholics and non-alcoholics was made. The predicative capability of estimating a BAC from both the zero and first order theories was also investigated. It was concluded that ethanol elimination is a zero order process. For subjects classified as non-drinkers (consume less than 6 ounces of ethanol/month), the mean ethanol elimination rate as determined in the study was 12 +/- 4 mg/h. For subjects classified as social drinkers (consume more than 6 ounces but less than 30 ounces of ethanol/month), the mean ethanol elimination rate was 15 +/- 4 mg%/h, and for alcoholics, the mean ethanol elimination rate was 30 +/- 9 mg%/h. These results indicate that the rate of ethanol elimination increases with drinking experience.

Effect of short-term storage conditions on alcohol concentrations in blood from living human subjects

We examined the effects of time, temperature, and a preservative (sodium fluoride) on ethanol concentrations in stored samples of whole blood from living human subjects. We measured the ethanol in the first, second, seventh, and 14th day of storage, by gas chromatography. Samples were stored at 0-3 degrees C and at 22-29 degrees C, with and without preservative. None of these showed significant gains or losses in concentration. The average differences between ethanol as measured on the day of collection and after storage were all within the range of experimental error of the method (+/- 5%).

Effect of short-term storage conditions on alcohol concentrations in blood from living human subjects

We examined the effects of time, temperature, and a preservative (sodium fluoride) on ethanol concentrations in stored samples of whole blood from living human subjects. We measured the ethanol in the first, second, seventh, and 14th day of storage, by gas chromatography. Samples were stored at 0-3 degrees C and at 22-29 degrees C, with and without preservative. None of these showed significant gains or losses in concentration. The average differences between ethanol as measured on the day of collection and after storage were all within the range of experimental error of the method (+/- 5%).

Blood, bone marrow and eye fluid ethanol concentrations in putrefied rabbits

The effect of putrefaction on postmortem blood, bone marrow and eye fluid ethanol levels was evaluated in rabbits. Control and dosed animals were sacrificed and stored at either room temperature (approx. 19 degrees C) or cold temperature (approx. 3.5 degrees C) for as long as 28 days. Control animals stored at room temperature showed ethanol levels in the bone marrow that peaked at 7 days after sacrifice, followed by decreases to a nondetectable level at 21 days. Overall decreases were demonstrated in bone marrow of dosed rabbits stored at room temperature for all postmortem intervals. The control animals stored at low temperature showed no ethanol in the bone marrow and blood until 21 days after sacrifice. Dosed rabbits stored at low temperature showed no significant changes in blood and marrow ethanol until 21 days after sacrifice.

The influence of physical properties and lipid content of bile on the human blood/bile ethanol ratio

The relationship between ethanol levels in blood and bile was determined in human postmortem specimens. The influences of several physical properties--surface tension, specific gravity and viscosity--and bile lipid content on the blood/bile ethanol ratio were evaluated. A gas chromatographic direct injection technique was employed to determine the ethanol concentrations in postmortem blood and bile specimens. A positive correlation was established between the levels in the two fluids. No correlation could be found between the blood/bile ethanol ratios and the aforementioned physical properties of bile. Correction of the observed bile ethanol for lipid content had an insignificant effect on the ratio. The average blood/bile ethanol ratio was 1.03 +/- 0.29 (range: 0.32-2.91). The wide range observed makes it undesirable to use bile ethanol concentrations to predict specific blood ethanol concentrations. However, under certain conditions, bile ethanol levels may be used to estimate blood concentrations within a range of values.

Blood versus bone marrow isopropanol concentrations in rabbits

The use of bone marrow to determine the blood isopropanol concentrations becomes important when a blood specimen is contaminated or unavailable. The blood/ marrow isopropanol ratios were determined in rabbits autopsied 0, 4, and 24 h after sacrifice. The lipid content of the individual marrow specimens was shown to have a significant influence on the range of ratios. When the determined marrow isopropanol concentrations were corrected for lipid content, a better correlation between blood and marrow concentrations was obtained. The ratio (1.45 +/- 0.17) was not altered significantly by postmortem time or temperature. Although acetone was not exogenously administered to the rabbits, but rather was endogenously produced from isopropanol metabolism, the relationship between blood and marrow acetone concentrations was somewhat linear. However, the range of observed and corrected blood/marrow acetone ratios was altered significantly by storage temperature, and delays between death and analysis. Thus, under the experimental conditions of this study, marrow isopropanol concentrations may be used to predict blood isopropanol concentrations, whereas marrow acetone concentrations can not.

Blood versus bone marrow methanol concentrations in rabbits

Postmortem methanol levels in bone marrow and heart blood were determined in rabbits. The average ratio of blood concentration to observed bone marrow concentration in 36 rabbits was 2.6 +/- 0.6 with a range of 1.5 to 4.2. Correcting for the lipid content of the bone marrow decreased the average ratio, reduced the ratio range and improved the correlation. The heart blood to corrected bone marrow ratio was 1.6 +/- 0.3 with a range of 1.2 to 2.9. Direct injection gas chromatographic techniques were employed to quantitate methanol concentrations.

Plasma versus bone marrow flurazepam concentration in rabbits

Methods for the quantitation of flurazepam in plasma and bone marrow were developed for the purpose of determining the relationship between flurazepam concentrations in both tissues. Albino New Zealand rabbits, given flurazepam in doses of 5, 10, or 20 mg/kg, were sacrificed either one or three hours after drug administration. Flurazepam concentrations in plasma and bone marrow were determined utilizing a gas-liquid chromatograph equipped with an electron capture detector. the average plasma/bone marrow flurazepam ratios were 0.033 +/- 0.012 and 0.024 +/- 0.012 for rabbits sacrificed one hour and three hours after dosing, respectively. This study showed that a range of plasma flurazepam levels can be estimated from known bone marrow concentrations. The overall mean plasma/bone marrow ratio for all rabbits used in this study was 0.029 +/- 0.012 with a range of 0.010 to 0.055.

Pepper sauce toxicity

An acute oral LD50 of Pepper Sauce in male white Sprague-Dawley rats was determined to be 23.58 ml/kg with upper and lower limits of 29.75 and 18.70 ml/kg, respectively, at the 0.95 confidence level. In the female rats, the LD50 was determined to be 19.52 ml/kg with upper and lower limits of 24.35 and 15.64 ml/kg, respectively, at the 0.95 confidence level. This sex variation was found to be insignificant. A subchronic oral toxicity evaluation of Pepper Sauce in male and female white Sprague-Dawley rats revealed no gross or microscopic pathological changes in the animals nor were any significant biochemical changes noted. The growth rates remained within normal range. Pepper Sauce was shown to be a mild skin irritant and a moderate to severe eye irritant in New Zealand albino rabbits; vinegar, an ingredient of Pepper Sauce, was shown to contribute significantly to the ocular toxicity. The Pepper Sauce did not induce terata in Sprague-Dawley rats nor skin sensitization in guinea pigs.

A comparative study of analytical methods to determine postmortem changes in carbon monoxide concentration

Twenty-one autopsy blood samples were analyzed using spectrophotometric and gas chromatographic procedures after storage for 30 and 150 days. When carboxyhemoglobin was measured spectrophotometrically at the absorbance ratio of 540 nm/555 nm, the observed average percent losses were 8 +/- 9% and 35 +/- 27% after 30 and 150 days of storage, respectively. When measured at the absorbance ratio of 540 nm/579 nm, the average percent losses of carboxyhemoglobin were 7 +/- 8% and 34 +/- 25% after 30 and 150 days, respectively. Wavelength shifts and distorted spectral scans were observed at 150 days. When carbon monoxide was determined by gas chromatographic methods based on combining capacity, the average percent loss was 15 +/- 24% and 37 +/- 36% after 30 days and 150 days, respectively. The average percent loss of calculated CO based on hemoglobin concentration after 30 days was 31 +/- 14% and at 150 days, 40 +/- 24%. The average percent loss of calculated CO based on iron content was 23 +/- 13% and 37 +/- 23% after 30 and 150 days, respectively.

A comparative study of ethchlorvynol levels in blood versus bone marrow

Bone marrow may be utilized as an alternative biological sample in cases where uncontaminated blood samples are not available for analyses. Bone marrow/blood ratios of ethchlorvynol as a function of time and dosage level were determined in 40 rabbits. A modified quantitative analysis that produced accurate and reproducible results was employed for the determination of ethchlorvynol levels. Further, ten blood and bone marrow samples containing ethchlorvynol were chosen to study the effects of storage for a period of 24 hours. Studies of blood and bone marrow ethchlorvynol levels with time showed no linear relationship. Bone marrow/blood ratios as a function of dose resulted in close mean averages with a wide range of values. Significant losses in both blood and bone marrow ethchlorvynol levels were evidenced in most of the samples subjected to the 24-hour storage study.

Comparative study of ethanol levels in blood versus bone marrow, vitreous humor, bile and urine

Post-mortem ethanol levels in blood were compared to corresponding levels in rib bone marrow, vitreous humor, urine and bile. In forensic toxicology, a good correlation between blood and a tissue or body fluid is needed to estimate a blood alcohol concentration when blood is unavailable or contaminated. In this study, direct injection and headspace gas-chromatographic techniques were employed to quantitate the ethanol concentrations. Comparable findings by these two techniques showed a reproducibility of results. When the determined bone marrow ethanol levels were corrected for the lipid fraction, a consistent correlation could be established between ethanol levels in blood and bone marrow. The relationship (linearity and ratio range) between ethanol levels in blood and corrected levels in bone marrow was better than that between blood and vitreous humor, bile or urine. This study showed that blood ethanol levels can be predicted by extrapolating the corrected rib bone marrow ethanol level.