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PubMed1980

Antiarrhythmic effects of four different beta-adrenergic blockers in the mouse chloroform arrhythmia model.

The antiarrhythmic activity of four different beta-adrenergic blockers was assessed in the mouse chloroform arrhythmia model. ED50 values and 95% confidence intervals established by i.p. administration of drug were: propranolol (22.8, 10.9--67.0 mg/kg), sotalol (38.0, 15.9--58.5 mg/kg) and practolol (167, 111--235 mg/kg). Butoxamine provided some protection against the arrhythmia within a narrow dose range (53 to 79 mg/kg).

Adrenergic beta-Antagonists↗
PubMed1983

Chloroform-methanol extraction method for determination of fat in foods: collaborative study.

A chloroform-methanol extraction method (complete extraction of fat in 3 min) for determining fat in processed and prepared foods has been studied collaboratively. Fourteen collaborators reported single replicate fat results on 7 samples representative of various food types and 2 spiked samples by the proposed method. Each sample was accompanied by a blind duplicate. For statistical purposes, the blind duplicates were treated as paired observations, and there were 2 laboratory outliers. There was a 97.9% agreement among the results from the remaining 12 collaborators and the Associate Referee for the unfortified samples. Recoveries of 93.8 and 98.3% were obtained on fortified samples, based on results obtained from 11 collaborators. The statistical analysis of the results indicate (ranges for standard deviations were Sr = 0.083-0.528, Sb = 0.101-0.379, Sd = 0.130-0.631, for fat values ranging from 1.58 to 26.91%) that this method is adequate for quantitating the fat content in a wide variety of processed foods for nutritional labeling. The method has been adopted official first action.

Chloroform↗
PubMed1981

[A study of the cytotoxicity of chloroform, 1-2-dichloroethane, 1,1,1-trichloroethane and hexachlorobutadiene to mouse L cells (author's transl)].

A cytotoxicity test based on residual protein determination is described and the in vitro toxicity of certain chlorinated aliphatic hydrocarbons is evaluated with this test. The results obtained are sufficiently reproducible to yield an order of cytotoxicity: hexachlorobutadiene is about 100-fold more toxic than chloroform or 1,2-dichloroethane; whereas, 1,1,1-trichloroethane is 10-fold more toxic than these two compounds. The method is fast and lends itself to the toxic evaluation of large numbers of samples.

Animals↗
PubMed1996

Changes in spleen and thymus cell phenotypes in mice vaccinated with the Coxiella burnetii phase I whole-cell vaccine or the chloroform-methanol residue subunit vaccine.

Lymphoid cell phenotypes within the spleen and thymus were analyzed to determine whether numerical or proportional changes in cell populations could account for the immunosuppression seen after vaccination of mice with inactivated phase I Coxiella burnetii whole-cell vaccine (WCI). Within 21 days of vaccination with WCI, there was a reduction in the percentage of splenic T cells and B cells while the numbers of thymic T cells and B cells increased. A substantial percentage of spleen cells did not bear typical T cell or B cell surface markers. In contrast, except for an early rise (by day 3) in the numbers of T and B cells, injecting the chloroform-methanol residue subunit-vaccine (CMR) caused no significant phenotypic changes of lymphoid cells in the spleen or thymus. The percentage of thymus cells bearing T cell phenotypes was similar in mice vaccinated with WCI or CMR. However, the total number of T cells in the thymus dramatically decreased in mice vaccinated with WCI. There was no correlation between the lymphocyte hyporesponsiveness to mitogens and WCI in vitro and the increased numbers of CD8-positive splenocytes. These results suggest that WCI vaccination caused dramatic changes in splenocyte and thymocyte lymphocyte populations and provide evidence for the more benign nature of the CMR vaccine.

Animals↗
PubMedDate not supplied

[Suicidal chloroform poisoning].

The results of the autopsy and of the toxicological analysis of a suicidal poisoning case by chloroform inhalation of a man (28) are described. The cause of death was acute cardiac failure, accompanied by centrolobular liver necroses. Quantitative analytical results (e.g. blood 47, liver 188, kidney 144, brain 74, urine 2 ug/ml, determined by head space GC were in agreement with literature data. The low concentration in stomach content indicated inhalation in accordance to the findings on site.

Adult↗
PubMed1998

Evidence of polydrug use using hair analysis: a fatal case involving heroin, cocaine, cannabis, chloroform, thiopental and ketamine.

A case is presented involving a young woman on several illicit drugs (heroin, cocaine and cannabis) as well as two medications and a solvent used for their anesthetic and narcotic properties: thiopental, ketamine and chloroform. This complex drug use was supported by hair analysis over a 10.5 cm segment of the hair taken at autopsy. The average measured concentrations in hair were: thiopental = 5.3 ng/mg, pentobarbital = 10.0 ng/mg, ketamine = 11.3 ng/mg norketamine = 1.0 ng/mg, diazepam = 1.2 ng/mg, nordiazepam = 0.1 ng/mg, 6-acetylmorphine = 4.4 ng/mg, morphine = 3.4 ng/mg, codeine = 1.2 ng/mg, cocaine = 5.5 ng/mg, benzoylecgonine = 1.5 ng/mg and methylecgonine ester = 1.0 ng/mg. While the ketamine/norketamine ratio is consistent with that already reported on drug detection in hair, the thiopental/pentobarbital ratio seems to be inverted.

Adult↗
PubMedDate not supplied

[A modification to the chloroform-methanol method of isolating the matrix protein of the influenza virus].

A modification of chloroform-methanol method of isolation of M1 protein (M1P) of human influenza A virus allowed increasing 1.6 times the yield of the target product and decreasing 6.4 times the amount of organic solvents. It has been shown that M1 protein isolated by the modified method did not differ (as to its physicochemical characteristics and antigenic activity) from M1 protein isolated by means of the initial method.

Animals↗
PubMed1996

Use of p-nitrophenyl chloroformate chemistry to immobilize protein on orthopedic biomaterials.

Biochemical surface modification involves covalently immobilizing biomolecules onto biomaterial surfaces to induce specific biological responses. This approach may be useful for enhancing the fixation of orthopedic implants. p-Nitrophenyl chloroformate (p-NPC) was used to immobilize protein on bulk samples of Co-Cr-Mo and Ti-6Al-4V. Activation of both materials was dependent on the concentration of p-NPC, with a maximum of approximately 1.5 active groups/nm2 of nominal surface area. Trypsin was used as a model protein because much is known about its structure and mode of action. Derivatization with 0.65 mg p-NPC/cm2 resulted in significantly greater enzymatic activity (7.4 BAEE [N-(alpha)-benzoyl-L-arginine ethyl ester hydrochloride] units) on the Co-Cr-Mo samples compared with higher concentrations of p-NPC (5 BAEE units) and with simple adsorption of trypsin (1.5 BAEE units). An activity of 10.5 BAEE units was measured on both adsorbed and p-NPC-activated Ti-6Al-4V, with the exception of samples derivatized with 1.95 mg p-NPC/cm2, on which activity was significantly lower (4 BAEE units). In probing the linkages between trypsin and biomaterial by treatment with chaotropic agents, guanidine hydrochloride (GuHCl) was observed to eliminate more enzymatic activity than was urea. On Co-Cr-Mo samples, GuHCl removed nearly all the trypsin activity, while urea significantly decreased the activity only at a concentration of 0.65 mg p-NPC/cm2. Treatment of Ti-6Al-4V samples with GuHCl caused a trend of decreasing activity with increasing concentration of p-NPC, whereas urea had no effect on immobilized trypsin activity.

Adsorption↗
PubMed2001

Electrically driven microseparation methods for pesticides and metabolites: VI. Surfactant-mediated electrokinetic capillary chromatography of aniline pesticidic metabolites derivatized with 9-fluoroenylmethyl chloroformate and their detection by laser-induced fluorescence.

In this report, we describe a surfactant-mediated electrokinetic capillary chromatography (SM-EKC) system for the separation of 9-fluoroenylmethyl chloroformate (FMOC)-derivatized anilines by capillary electrophoresis (CE). The SM-EKC system consisted of dioctyl sulfosuccinate (DOSS)/acetonitrile mixtures and was suited for the CE separation of the relatively hydrophobic FMOC-aniline analytes and other neutral compounds, e.g. alkylphenyl ketones. While the organic modifier acetonitrile (ACN) allowed the solubilization of the hydrophobic solutes and maintained the DOSS surfactant in its monomeric form by inhibiting micellization, the DOSS surfactant associated with the FMOC anilines to a varying degree thus leading to their differential migration and separation. Under these conditions, the FMOC-anilines were readily detected at the 10(-6) M level by UV at 214 nm and at the 10(-8) M level by laser-induced fluorescence (LIF) using a solid-state UV laser operating at 266 nm line as the excitation wavelength. The FMOC precolumn derivatization was also readily performed in lake water spiked with anilines at near the limit of detection (LOD) level. The lake water matrix showed no significant effects on the extent of derivatization at the LOD level as well as on the detection of the analytes due to the selectivity of the FMOC derivatization. The derivatization and detection of spiked lake water necessitated only the removal of microparticles by microfiltration prior to derivatization and detection.

Aniline Compounds↗
PubMed1988

1,1,1-Trichloroethane (methyl chloroform) in urine as biological index of exposure.

Fifteen human volunteers were exposed to 1,1,1-trichloroethane (methyl chloroform) vapor at 72-495 mg/m3 for a period of 2 to 4 hours at rest (ten cases) and during light physical exercise (five cases). Subsequently 60 workers occupationally exposed to 1,1,1-trichloroethane in a refrigerator manufacturing plant were studied (median value: 178 mg/m3; geometrical standard deviation: 2.19 mg/m3). As expected, the relative uptake (R) of 1,1,1-trichloroethane decreased in the course of exposure at rest (R = 0.44 after 20 minutes of exposure; R = 0.26 after 240 minutes of exposure). Both in the experimentally exposed subjects and in the occupationally exposed workers, the urinary concentration of 1,1,1-trichloroethane showed a linear relationship to the corresponding environmental time-weighted average concentration. The correlation coefficients (r) were 0.95 in occupationally exposed subjects and more than 0.90 in experimentally exposed groups. A linear equation also existed between urinary concentration and amount of 1,1,1-trichloroethane absorbed (r = 0.88). The findings indicate that the urinary concentration of 1,1,1-trichloroethane can be used as an appropriate biological exposure indicator. In occupationally exposed subjects performing moderate work, the urinary 1,1,1-trichloroethane concentration corresponding to the time-weighted average of the threshold limit value was found to be 860 micrograms/L and its 95% lower confidence limit (biological threshold) 805 micrograms/L.

Adult↗
PubMed2006

Quantification of fudosteine in human plasma by high-performance liquid chromatography-electrospray ionization mass spectrometry employing precolumn derivatization with 9-fluorenylmethyl chloroformate.

This paper describes a novel method for the sensitive and selective determination of fudosteine in human plasma. The method involves a derivatization step with 9-fluorenylmethyl chloroformate (FMOC-Cl) in borate buffer and detection based on high-performance liquid chromatography-electrospray ionization mass spectrometry (LC/ESI/MS). After acetonitrile-induced protein precipitation of plasma samples, fudosteine was derivatized with FMOC-Cl, then extracted by ethyl acetate, evaporated, reconstituted and injected using an LC/ESI/MS instrument. Separation was achieved using an ODS column and isocratic elution. Excellent linearity was obtained for the entire calibration range from 0.05 to 20 microg/ml. Validation assays of the lower limit of quantification (LLOQ) as well as for the intra- and inter-batch precision and accuracy met the international acceptance criteria for bioanalytical method validation. Using the developed analytical method, fudosteine could be detected for the first time in human plasma with a low limit of detection (LLOD) of 0.03 microg/ml. The proposed method has been successfully applied to study the pharmacokinetics of fudosteine in healthy Chinese volunteers after single and multiple oral administration.

Administration, Oral↗
PubMed2006

High performance liquid chromatography for the determination of glucosamine sulfate in human plasma after derivatization with 9-fluorenylmethyl chloroformate.

In this study, we developed a simple, rapid, sensitive, and reliable method for the determination of glucosamine sulfate in human plasma, which was based on derivatization with 9-fluorenylmethyl chloroformate (FMOC-Cl) followed by reverse-phase HPLC-FLD. For the first time, FMOC-Cl was introduced into derivatization of glucosamine sulfate in human plasma. The amino groups of glucosamine sulfate and vertilmicin sulfate (the internal standard) were trapped with FMOC-Cl to form glucosamine-FMOC-Cl and vertilmicin-FMOC-Cl adducts, which can be very suitable for HPLC-FLD. Precipitation of plasma proteins by acetonitrile was followed by vortex mixing and centrifugation. Chromatographic separation was performed on a C18 column (DIAMONSIL 150 x 4 mm id, 5 microm) with a mobile phase gradient consisting of acetonitrile and water at a flow-rate of 1 mL/min. The retention times of glucosamine-FMOC-Cl and vertilmicin-FMOC-Cl adducts were 8.9 and 21.2 min, respectively. This method was shown to be selective and sensitive for glucosamine sulfate. The limit of detection was 15 ng/mL for glucosamine sulfate in plasma and the linear range was 0.1-10 mg/mL in plasma with a correlation coefficient (r) of 0.9999. The relative standard deviations (RSDs) of intra-day and inter-day assays were 5.2-8.1% and 6.1- 8.5%, respectively. Extraction recoveries of glucosamine sulfate in plasma were greater than 90%. The validated method was successfully applied to the determination of glucosamine sulfate in human plasma samples.

Blood Chemical Analysis↗
PubMed2004

Ultrastructural changes in the testis and epididymis of rats following treatment with the benzene chromatographic fraction of the chloroform extract of the seeds of Carica papaya.

The benzene chromatographic fraction of the chloroform extract of the seeds of Carica papaya at a dose of 10 mg/rat/day for 150 days, which has shown a total inhibition of motility, reduced sperm count and infertility, was tested to de fi ne the mode of action at the subcellular level in the testis and epididymis. The ultrastructure of the testis of the treated animals revealed no appreciable changes in the subcellular characteristics. The mechanism of protein synthesis as well as steroidogenesis were evident in the Sertoli cells while the spermatogonia, spermatocytes and spermatids, both round and elongated, depicted a prominent nucleus, distinct nuclear membrane and cytoplasmic characteristics indicating normal germ cell differentiation. The principal cells of the cauda epididymis were characterized by the presence of well-de fi ned rough endoplasmic reticulum, mitochondria, Golgi bodies and secretary granules, suggesting active secretory functions. The absorptive function of the cauda epididymis was evidenced by the presence of numerous vesicles and multivesicular bodies adjacent to stereocilia. It is concluded that the inhibition of sperm motility by the drug could be due to other epididymal factors rather than the subcellular characteristics of testis and epididymis.

Animals↗
PubMed2004

Rapid determination of amino acids in neonatal blood samples based on derivatization with isobutyl chloroformate followed by solid-phase microextraction and gas chromatography/mass spectrometry.

The purpose of this study was to develop a simple, rapid and sensitive analytical method for determination of amino acids in neonatal blood samples. The developed method involves the employment of derivatization and a solid-phase microextraction (SPME) technique together with gas chromatography/mass spectrometry (GC/MS). Amino acids in blood samples were derivatized by a mixture of isobutyl chloroformate, methanol and pyridine, and the N(O,S)-alkoxycarbonyl alkyl esters thus formed were headspace extracted by a SPME fiber. Finally, the extracted analytes on the fiber were desorbed and detected by GC/MS in electron impact (EI) mode. L-Valine, L-leucine, L-isoleucine, L-phenylanaline and L-tyrosine in blood samples were quantitatively analyzed by measurement of the corresponding N(O,S)-alkoxycarbonyl alkyl esters using an external standard method. SPME conditions were optimized, and the method was validated. The method was applied to diagnosis of neonatal phenylkenuria (PKU) and maple syrup urine disease (MSUD) by the analyses of five amino acids in blood samples. The results showed that the proposed method is a potentially powerful tool for simultaneous screening for neonatal PKU and MSUD.

Amino Acids↗
PubMed2005

Gas chromatography/mass spectrometry determination of amphetamine-related drugs and ephedrines in plasma, urine and hair samples after derivatization with 2,2,2-trichloroethyl chloroformate.

A new analytical approach, based on derivatization with 2,2,2-trichloroethyl chloroformate and gas chromatography/mass spectrometry (GC/MS), was investigated for qualitative and quantitative analyses of a large range of amphetamine-related drugs and ephedrines in plasma, urine and hair samples. Sample preparation involved alkaline extraction of analytes from biological samples using Extrelut columns, after addition of the internal standard 3,4-methylenedioxypropylamphetamine (MDPA), and subsequent derivatization to produce 2,2,2-trichloroethylcarbamates. GC/MS analyses, in splitless mode using a slightly polar 30-m capillary column, were performed with quadrupole or ion trap instruments. MS acquisition modes were electron ionization (EI) in full-scan or selected ion monitoring (SIM) modes (quadrupole), and full-scan MS or MS/MS modes with chemical ionization (CI) conditions (ion trap). EI spectra of 2,2,2-trichloroethylcarbamates showed variably abundant molecular ions as well as abundant diagnostic fragment ions, both characterized by ion clusters reflecting the isotope distribution of three chlorine atoms in the derivatized molecules. CI spectra showed abundant protonated molecules. Quantitative studies using EI SIM conditions gave recoveries in the range 74-89%, linear response over ranges of 10-2000 ng/mL (plasma and urine) and 0.20-20 ng/mg (hair), with corresponding limits of detection in the ranges 2-5 ng/mL and 0.1-0.2 ng/mg. Potential applications (following full method validation) include clinical and forensic toxicology, as well as doping control.

Amphetamines↗
PubMed1996

Analysis of amino acids in biological fluids by pentafluorobenzyl chloroformate derivatization and detection by electron capture negative ionization mass spectrometry.

Pentafluorobenzyl chloroformate (PFBCF) has been utilized as a derivatization reagent for amino acids (AAs) in biological fluids with susequent detection by electron capture negative ionization mass spectrometry (ECNI/MS). AAs were derivatized in one step in aqueous solution, plasma, and whole blood at room temperature. To demonstrate quantitative analysis, phenylalanine concentrations were determined in human plasma. AAs were derivatized in one step using PFBCF and a mixture of water, ethanol, and pyridine/dimethylaminopyridine. The N-pentafluorobenzyloxycarbonyl amino acid ethyl esters (f phi-AA-OEt) exhibited good GC properties and the ECNI mass spectra are dominated by the [M-181]- ion. The f phi-AA-OEt derivatives can be easily detected at the femtomole level by selected ion monitoring. Phenethyl alcohol was also derivatized, using anhydrous conditions, and the resulting PFB carbonate's ECNI mass spectrum was dominated by the [M-181]- ion. The ECNI molar response of the PFB carbonate derivative is two times that of the corresponding pentafluorobenzoate.

Alcohols↗
PubMed1996

Amino acid analysis by reverse-phase high-performance liquid chromatography: improved derivatization and detection conditions with 9-fluorenylmethyl chloroformate.

An improved method for the quantitative derivatization of amino acids with fluorenylmethyl chloroformate (FMOC-Cl) is described. Amino acids are derivatized in borate buffer at pH 11.4 for 40 min at ambient temperature. All amino acids resulted in stable derivatives. In particular, improved derivatization was obtained with the troublesome amino acids His and Tyr: exclusively monosubstituted His and disubstituted Tyr were formed, eluting as free peaks in the chromatogram. These derivatives show a higher fluorescence response than their disubstituted and monosubstituted counterparts, respectively, resulting from other protocols. Under the new conditions, considerable less of the hydrolysis product of FMOC-Cl is seen in the chromatograms. Baseline noise was substantially reduced at a higher emission wavelength (630 nm instead of 313 or 340 nm). With simple precautions, extensive adsorption of the disubstituted derivatives (Lys, Hyl, and Tyr) on plastic or glass surfaces could be prevented. Calibration curves were linear over a 10 to 300 molar ratio of FMOC-Cl to total amino acid. The detection limits are in the femtomole range and the derivatives are stable for more than 48 h, thus permitting automated analysis of multiple samples.

Amino Acids↗
PubMed1997

Measurement of histidinohydroxylysinonorleucine and hydroxyproline in skin collagen by reversed-phase high-performance liquid chromatography after 9-fluorenylmethyl chloroformate labeling.

A novel, highly sensitive method to quantify histidinohydroxylysinonorleucine (HHL), a trifunctional type of cross-link in skin collagen, was developed. HHL in skin hydrolysates labeled with 9-fluorenylmethyl chloroformate (FMOC-Cl) was separated by reversed-phase high-performance liquid chromatography. Mass spectrometric analysis revealed that two FMOCs were bound to two primary amino acid residues, histidine and hydroxylysine, but not to lysine residue in one HHL molecule. Hydroxyproline was simultaneously measured to express the molar ratio of HHL to collagen. The detection range of HHL was from 1 to 10 pmol and that of hydroxyproline from 1 to 50 pmol. A 6-mm punch-biopsied human skin sample contained 0.40 to 0.69 mol of HHL per one molecule of collagen. This sensitive method is useful as it is rapid and can be used to examine the aging process or the change of HHL content in skin collagens of various pathologic states.

Chromatography, High Pressure Liquid↗