[Two cases of methanol poisoning with chronological measurements of blood concentrations of methanol, ethanol and formate].

We report two cases of methanol poisoning and evaluate the kinetics of methanol, ethanol, and formate. The first case was a 48-year-old man (case 1). His initial methanol level was 56.4 mg/dL and serum ethanol level was 2.4 mg/dL. Serum formate was not detected, and ethanol administration was initiated. However, methanol was eliminated slowly, and serum formate increased. His methanol and formate levels decreased rapidly following hemodialysis. He was discharged without any sequelae. The second case was a 35-year-old man (case 2). His serum methanol level was 400 mg/dL, and serum ethanol was not detected. His serum formate level was 13.4 mg/dL, and ethanol and activated folate were administered. He underwent hemodialysis immediately after diagnosis. Methanol and formate decreased rapidly, and he was discharged without any sequelae. Methanol and formate are eliminated slowly if ethanol is administered alone. We suggest that hemodialysis should be considered immediately after ethanol administration.

[Analysis of bialaphos and its active metabolite L-glufosinate in biological specimens by HPLC].

The symptoms of acute poisoning caused by ingestion of bialaphos (BIAL), an ingredient of herbicide, are supposed to be due to the L-glufosinate (L-GLUF), which is formed by the degradation of bialaphos. To elucidate the pharmacokinetics of BIAL and L-GLUF, we attempted a simultaneous analysis of BIAL and L-GLUF in biological samples by exploiting a reversed phase HPLC method. The derivatization reaction of BIAL and L-GLUF using (+) -1- (9-fluorenyl) ethyl chloroformate was completed in 30 min at 40 degrees C and both derivatives were stable for 48 hr at 25 degrees C. A fluorescence detector were used for HPLC; the exicitation wavelength was set at 265 nm and the emission wavelength at 315 nm. Respective calibration curves prepared by adding BIAL and L-GLUF to serum were linear within ranges of 0.01-10.0 and 0.005-10.0 microg/mL in derivatived liquid samples for introducing into HPLC. The lower limits of detection for BIAL and L-GLUF were 0.005 and 0.001 microg/mL, respectively. An 83-year old male who ingested approximately 350 mL of Herby Liquid, a herbicide containing 18% BIAL and 82% surfactant, in an attempt to commit suicide developed delayed respiratory depression and seizures. L-GLUF was detected in the serum of the patient 2.7 hr after ingestion, but BIAL was not. The change in serum L-GLUF concentration measured over time was consistent with a 2-compartment model, with a distribution half-life of 1.70 hr and an elimination half-life of 6.03 hr.

[Clinical usefulness of the acetaminophen detection kit in treating acute poisoning--data from a survey of 28 cases treated at Niigata City general hospital].

In acute poisoning caused by acetaminophen (N-acetyl-p-aminophenol, APAP), it is critical to predict the onset of delayed liver injury based on the prompt measurement of serum APAP level and to administer the antidote N-acetylcysteine (NAC) without delay as needed. However, all emergency medical facilities are not necessarily equipped with an expensive analytical instrument that allows prompt determination of APAP. Here, we tested the clinical usefulness of the Acetaminophen Detection Kit (Kanto Chemical Co., Ltd.), which claims to rapidly detect APAP in serum using a simple procedure, by spectrophotometrically measuring the APAP concentration in 34 serum samples collected from 28 patients with acute APAP poisoning. The results showed that the correlation coefficient between the APAP value measured by the Acetaminophen Detection Kit and that determined by the HPLC method was, at 0.888, not very high, but that the decision on whether to administer NAC based on the measured APAP level was consistent between the two analytical methods in 23 out of 25 patients. Also, the value obtained by the Acetaminophen Detection Kit was equal to, or larger than, that obtained by the HPLC method, suggesting that it is unlikely that patients requiring NAC would be left untreated. These results indicate that the Acetaminophen Detection Kit, with its ease and simplicity of use, is clinically useful in emergency medical facilities for which an expensive analytical instrument is not affordable.

[Diphenhydramine poisoning presented with psychotic-like symptoms and choreic involuntary movement: report of two cases].

We encountered two cases of diphenhydramine-containing hypnotics overdose, exhibiting delirium and involuntary choreic movement. In case 1, a 32-year-old man ingested 24 tablets of Drewell, each containing 25 mg diphenhydramine, in a suicidal attempt. About four hours after ingestion, he showed generalized convulsion, delirium, and involuntary choreic movements. Intravenous diazepam was ineffective and he was sedated with continuous infusion of propofol. About 15 hours after ingestion and on discontinuing the sedation, he became alert and did not show any neurological abnormality. The blood concentration of diphenhydramine, measured by liquid chromatography/electrospray mass spectrometry (LC/MS), was 1.26 microg/ mL. In case 2, a 24-year-old woman ingested 114 tablets of Drewell and was admitted to our hospital. Her consciousness was impaired and she was treated with intravenous fluids. About four hours after ingestion, she became restless and showed confusion, agitation, and involuntary choreic movements. Sedation with continuous propofol infusion was required. She awoke the next day on discontinuing the sedation, and she did not show any neurological abnormalities. The blood concentration of diphenhydramine was 2.37 microg/mL. It is suggested that physicians should be aware of psychotic-like symptoms and choreic involuntary movement in patients with diphenhydramine-containing hypnotics overdose.

Method for screening and quantitative determination of serum levels of salicylic Acid, acetaminophen, theophylline, phenobarbital, bromvalerylurea, pentobarbital, and amobarbital using liquid chromatography/electrospray mass spectrometry.

We investigated a method for the simultaneous screening, identification, and quantitative determination of salicylic acid, acetaminophen, theophylline, barbiturates, and bromvalerylurea, drugs that frequently cause acute poisoning in Japan and therefore require rapid analysis for effective treatment in the clinical setting. The method employs liquid chromatography/electrospray mass spectrometry (LC/MS) of solid-phase extracted serum samples. For LC/MS ionization, the electrospray-ionization method was used, with acetaminophen in the positive-ion mode, and salicylic acid, theophylline, phenobarbital, bromvalerylurea, pentobarbital, amobarbital, and o-acetamidophenol (internal standard) in the negative-ion mode, the base ions were used in each case for quantitative analysis. Quantitation was possible for the following sample concentration ranges: salicylic acid and acetaminophen, 100 to 5 microg/ml; theophylline, 100 to 0.5 microg/ml; and phenobarbital, bromvalerylurea, pentobarbital, and amobarbital, 100 to 1 microg/ml. Using full-scan mass spectrometry, the lower detection limits of 1 microg/ml for salicylic acid and acetaminophen, 0.1 microg/ml for theophylline, and 0.5 microg/ml for phenobarbital, bromvalerylurea, pentobarbital, and amobarbital were adequate for identifying acute poisoning. When each compound was added to serum to a final concentration of 5 microg/ml and solid-phase extraction was performed using Oasis HLB 1-cc (30-mg), the mean recovery rate of each compound was 89.2 to 96.1% (n=5), and the coefficients of variation of the intraday and interday assays were 3.55 to 6.05% (n=5) and 3.68 to 6.38% (n=5), respectively, which are acceptable. When this method of analysis was applied in testing the sera of a female patient who had consumed a large amount of an unknown commercial drug, salicylic acid and bromvalerylurea were identified, and the treatment strategy could be determined in accordance with the serum concentration of those drugs.

Rapid analysis method for paraquat and diquat in the serum using ion-pair high-performance liquid chromatography.

In the present study, by using IPCC-MS3 (GL Sciences Inc. Tokyo, Japan) as the counter-ion in the mobile phase, we established a simple, quick method of analysis that separated and quantified paraquat and diquat on an ODS column by introducing the deproteinized serum sample directly into HPLC. The calibration curve of paraquat and diquat detected at UV 290 nm showed good linearity when the concentration of the injected sample was in the range 0.1-10.0 microg/ml. The detection limit was 0.05 microg/ml, and the mean recoveries (n=5) added 1.0 microg/ml each of paraquat and diquat to standard serum were 87.5% and 89.1%, respectively, while the RSD were 4.52% and 3.85%. All of these were good results, and the time taken for one analysis was less than 30 min. As a result of employing this analytical method for the analyses in four cases of acute poisoning, it was possible to decide promptly on treatment approaches for all of the present cases.

Rapid analysis of 4-O-methylpyridoxine in the serum of patients with Ginkgo biloba seed poisoning by ion-pair high-performance liquid chromatography.

We have established a new method of HPLC analysis for the rapid separation from human serum and the quantification of 4-O-methylpyridoxine (MPN), which is contained in Ginkgo biloba seeds, and which, when consumed in large amounts, causes vomiting and convulsions. As a result of using IPCC-MS3 (GL Science, Tokyo, Japan), an ion-pair reagent, in the mobile phase, we succeeded in separating MPN in the deproteinized serum sample which was introduced directly onto the reverse-phase HPLC column. For the calibration curve of MPN standard solution, prepared with fluorescence detection at an excitation wavelength of 290 nm and an emission wavelength of 400 nm, a good linear relationship was obtained within the HPLC injection range of 10 ng-10 pg (in terms of the injected sample concentration, range: 1.0 microg/ml-1 ng/ml), allowing the detection of minute amounts, with the limit of detection (concentration of injected sample: 500 pg/ml) being 5 pg. In addition, when MPN solution was added to human reference serum to give a concentration of 0.002 microg/ml, the mean recovery rate was 92.5%, with RSD=7.09% (n=5). The time required for one analysis using this method is approximately 30 min, and thus it offers the advantages of greater speed and superior analytical sensitivity over the conventional methods, which require solid-phase extraction. We employed our new method to determine both the serum levels of MPN in 5 patients with Ginkgo biloba seed poisoning and the levels of free-form MPN in such seeds obtained in 8 regions of Japan.

Determination of the herbicide glyphosate and its metabolite in biological specimens by gas chromatography-mass spectrometry. A case of poisoning by roundup herbicide.

In Japan, poisonings by the glyphosate (GLYP)-containing herbicide Roundup and the gluphosinate (GLUF)-based herbicide BASTA have been increasing since about 1987. We applied the gas chromatography-mass spectrometry (GC-MS) method of analysis, on which we have already reported in regard to the determination of the blood serum level of GLUF and its metabolite, for the determination of serum and urinary levels of GLYP and its metabolite aminomethyl phosphonic acid (AMPA). Derivatization using N-methyl-N-(tert-butyldimethylsilyl) trifluoroacetamide was completed at a temperature of 80 degrees C after 30 min, and the detection limit of GLYP was 10 pg using m/z 454 and that of AMPA was 1 pg using m/z 396. The full mass spectra of 100 pg GLYP and of 10 pg AMPA were obtained easily. In extractions for which the Isolute HAX cartridge was employed, the mean recovery rate of GLYP and AMPA added to serum to yield concentrations of 10-0.1 microg/mL (n = 5) was 91.6 +/- 10.6% (or better), whereas that of GLYP and AMPA added to urine to yield concentrations of 100-1.0 microg/mL (n = 10) was 93.3 +/- 6.6% (or better), both of which were good rates. Also, using this method of analysis, the presence of GLYP was identified in the full mass spectra obtained from the serum of a patient who may or may not have ingested Roundup.

Rapid determination of total bromide in human serum using an energy-dispersive X-ray spectrometer.

Since the bromide preparations useful in the treatment of intractable infantile epilepsy show a tendency to accumulate in the body, they may cause chronic toxicosis. To prevent this, determination of the bromide ion concentration in the serum is essential. After establishing a simple and rapid technique using energy-dispersive X-ray spectroscopy for the analysis of the serum total bromide level, we applied this technique in a clinically diagnosed epilepsy patient. The standard curve for total bromide showed linearity (r=0.999) in the range of 10-2000 microg/ml, and the lowest detection limit was 5 microg/ml. The mean recovery rate of bromide added to reference serum to yield a concentration of 50 microg/ml was 93.5% (n=5, coefficient of variation=9.1%). Analysis took only 20 min. On analysis of the serum of a 10-year-old girl whose treatment was initiated with orally administered potassium bromide 1.0 g/kg, a good correlation was found between the total bromide level obtained with energy-dispersive X-ray spectroscopic analysis and the level of bromide ions determined by ion-exchange HPLC. The determination of serum total bromide by rapid energy-dispersive X-ray spectroscopic analysis is a useful method of monitoring to prevent bromide poisoning.

Toxicokinetics of DL-glufosinate enantiomer in human BASTA poisoning.

We found that glufosinate (DL-GLUF) was distributed in the spinal fluid in glufosinate poisoning. A 50-year old Japanese man (weighing 67 kg) attempted to commit suicide by ingesting about 100 ml of BASTA (containing DL-GLUF 18.5 g; ratio of D-GLUF to L-GLUF: 1 : 1). He was transported to our hospital, where serious respiratory depression was seen 26 h after ingestion, and management with artificial ventilation was initiated. The D-GLUF concentration 1 h after ingestion was 191.1 microg/ml, almost the same as that of L-GLUF 193.5 microg/ml, but by 3 h after ingestion, these levels had sunk to 60.3 microg/ml and 52.3 microg/ml, respectively, with the concentration of L-GLUF lower than that of D-GLUF. Later, at 27 and 35 h after ingestion, the D-GLUF level was still higher than the L-GLUF level, and the total amounts of urinary excretion were 2835 mg for D-GLUF and 2298 mg for L-GLUF, each variable thus showing a difference between the enantiomers. Cerebrospinal fluid taken from the patient 27 h after poison ingestion revealed the presence of DL-GLUF on CG-MS analysis, and quantitative HPLC analysis of the enantiomers indicated that the D-GLUF concentration was 0.48 microg/ml, and the L-GLUF concentration 0.12 microg/ml. The levels in blood collected at the same time were: D-GLUF, 1.44 microg/ml, and L-GLUF, 0.35 microg/ml. Also, the cerebrospinal fluid contained about one-third of the blood levels of both DL-GLUF enantiomers. He was discharged without any sequelae after 11 d of hospitalization.

Enantioselective analysis of glufosinate using precolumn derivatization with (+)-1-(9-fluorenyl)ethyl chloroformate and reversed-phase liquid chromatography.

We have developed a new analytical method to quantify the DL-homoalanine-4-yl(methyl)phosphinate (DL-GLUF) enantiomers in biological specimens using a reversed-phase high-performance liquid chromatography system with a fluorescence detection system. The derivatization of DL-GLUF enantiomers with (+)-1-(9-fluorenyl)ethyl chloroformate was carried out under mild conditions (40 degrees C for 30 min) without inducing racemization. The lower limit of quantitation was 0.01 microg/ml for both D-GLUF and L-GLUF, and the detection limit was 5 ng/ml. When DL-GLUF enantiomers were added to serum to produce concentrations between 0.1 and 100 microg/ml, the mean recovery rate was at least 93.8%. The recovery rate from urine was also satisfactory.

Gas chromatography-mass spectrometry analysis of 4-O-methylpyridoxine (MPN) in the serum of patients with ginkgo seed poisoning.

The 4-O-methylpyridoxine (MPN) present in the seeds of the Ginkgo biloba (maidenhair tree) has anti-vitamin B6 actions, and ginkgo seed poisoning can induce convulsions. We developed a specific quantitative method using gas chromatography-mass spectrometry for the analysis of MPN in human serum. The trifluoroacyl (TFA) derivative of MPN was obtained by treating MPN with trifluoroacetic anhydride at 50 degrees C for 5 min and remained stable for 6 h. The calibration curve of standard MPN obtained in the selective ion mode using the base ion (m/z 343) was linear between 100 pg and 10 ng, and the detection limit was 50 pg. The full mass spectrum of 100 pg of the TFA derivative of MPN was obtained easily. MPN was extracted from the serum with the use of a C18 solid-phase extraction cartridge. The recovery rate of MPN added to the serum at a concentration of 0.1 microg/mL was 90.0%.

[Simultaneous determination of propanil, carbaryl and 3,4-dichloroaniline in human serum by HPLC with UV detector following solid phase extraction].

In case of poisoning by herbicide compounded with Propanil (DCPA) and Carbaryl (NAC), we attempted simultaneous solid-phase extractions of DCPA, NAC, and 3,4-dichloroaniline (DCA), a metabolite of DCPA, from the patient's serum, and quantitative analytical method using HPLC-UV detection. With this HPLC method, the quantitative detection limits in the serum are 0.005 microgram/ml for DCPA and DCA and 0.001 microgram/ml for NAC, and the UV spectra of all three compounds could easily be obtained using a diode-array detection limit of 0.05 microgram/ml. When the three compounds were added to serum at concentrations ranging from 0.1-10.0 micrograms/ml, the recovery rates were satisfactory at between 91.1% and 101.9%. On analysis of the serum of patient who had ingested Kusanon A Emulsion, the ingested substance apparently caused an increase in the DCA concentration, which led to the appearance of methemoglobinemia. The possibility that the DCA concentration might be used for prognostic purposes was suggested.

Quantitative determination of glufosinate in biological samples by liquid chromatography with ultraviolet detection after p-nitrobenzoyl derivatization.

We have established a new HPLC method for derivatizing and quantifying glufosinate (GLUF) in human serum and urine using p-nitrobenzoyl chloride (PNBC). The p-nitrobenzoyl derivative of GLUF (PNB-GLUF) was produced quantitatively over 10 min at room temperature. PNB-GLUF possesses the property of ultraviolet (UV) light absorption with a lambda(max) of 272.8 nm, and was isolated from biological specimens by reversed-phase chromatography using Inertsil Ph-3. In experiments at a UV wavelength of 273 nm, GLUF has a quantitative detection limit of 0.005 microg/ml, and when it was added to both serum and urine to yield concentrations of 0.1-1000 microg/ml, its recovery rate was quite satisfactory: at least 93.8% in all cases. Further, the measured amounts of GLUF in 23 serum samples from patients intoxicated by ingestion of GLUF compared favorably with those obtained by fluorescence derivatization-HPLC using 9-fluorenylmethyl chloroformate (R=0.998). This technique of analysis is, in addition, applicable for Glyphosat, which possesses a chemical structure resembling that of GLUF, and it will be of great use in the determination of these two compounds.