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M Takino

Publications and source records attributed to M Takino.

At least 19 recordsLinked to original sources
PubMed2004

Atmospheric pressure photo-ionization liquid chromatography/mass spectrometric determination of aflatoxins in food.

A comparison between electrospray ionization (ESI) and the recent introduced atmospheric pressure photo-ionization (APPI) technique is described for the liquid chromatography/mass spectrometric (LC/MS) determination of aflatoxin B1, B2, G1 and G2 in food. For the optimization of APPI, several APPI ion source parameters were examined. Furthermore, the chemical noise and signal suppression of ESI and APPI by sample matrix interference were investigated. The results indicated that APPI has the low chemical noise and the little signal suppression in comparison with ESI. The mean recovery of each aflatoxin from peanuts, corn, nutmeg and red pepper sample spiked at 1 ng g(-1) ranged from 89 to 105% with relative standard deviations of 3.3-5.1%. The limit of detection (S/N = 3) in all food was in the range 0.11-0.5 ng g(-1). From these studies, it is suggested that APPI can be used as an additional tool in food residue analysis.

Aflatoxin B1↗
PubMed2001

Analysis of volatile sulphur compounds in breath by gas chromatography-mass spectrometry using a three-stage cryogenic trapping preconcentration system.

A method for the determination of trace volatile sulphur compounds (VSCs) including methanethiol, dimethyl sulfide (DMS) and dimethyl disulfide (DMDS) at low ppbv (volume/volume) in breath has been developed using a large volume preconcentration technique prior to capillary GC-MS analysis. The breath sample was collected in a 6-1 fused-silica-lined stainless steel canister and introduced into the three-stage cryogenic trapping preconcentration system by GC-MS in the total ion monitoring (scan) mode. The water condensation effect of breath sample inside the canister, which is due to the difference between human body temperature and laboratory temperature, was examined. The condensed water in the fused-silica-lined canister at 24 degrees C did not affect the recoveries of VSCs within 12 h. As this three-stage cryogenic trapping preconcentration technique made it possible to remove excess water [relative humidity (RH) >95%] and carbon dioxide (3.8%) without loss of the VSCs, more than 400 ml of the breath sample could be concentrated. The detection limits of methanethiol, DMS and DMDS in a breath sample using this method were 0.13, 0.09 and 0.15 ppbv, respectively.

Breath Tests↗
PubMed2001

Determination of polycyclic aromatic hydrocarbons by liquid chromatography-electrospray ionization mass spectrometry using silver nitrate as a post-column reagent.

Liquid chromatography-electrospray ionization mass spectrometry (LC-ESI-MS) using silver nitrate as a post-column reagent has been used for the determination of 10 polycyclic aromatic hydrocarbons (PAHs) in river water. In this method, after all the PAHs were separated by reversed-phase liquid chromatography, analytes formed complexes with silver cation by mixing with silver nitrate solution. The complexes then transfer the molecular ion, [M]+, of the PAHs by charge transfer using in source collision-induced dissociation. The positive ion ESI mass spectra of all PAHs tested in this study showed [M]+ as the base peak and abundant [M+Ag]+, [2M+Ag]- with very weak or no [2M+Ag]+. For the sample extraction, several solid-phase extraction parameters using the blue-chitin column were optimized. The limits of detection (S/N=3) of all PAHs for the spiked river water sample ranged from 0.001 to 0.03 ng/ml, and the detector responses were linear up to I ng/ml (correlation coefficients > or =0.0998). Repeatability and reproducibility were in the range from 4.3 to 6.8% and from 6.2 to 9.5%, respectively.

Chromatography, Liquid↗
PubMed2001

Analysis of waterborne paints by gas chromatography-mass spectrometry with a temperature-programmable pyrolyzer.

Gas chromatography-mass spectrometry (GC-MS) with a temperature-programmable pyrolyzer was used for the analysis of waterborne paints. Evolved gas analysis (EGA) profiles of the waterborne paints were obtained by this temperature-programmed pyrolysis directly coupled with MS via a deactivated metal capillary tube. The EGA profile suggested the optimal thermal desorption conditions for solvents and additives and the subsequent optimal pyrolysis temperature for the remaining polymeric material. Polymers were identified from pyrograms with the assistance of a new polymer library. The solvents were identified from the electron ionization mass spectra with the corresponding chemical ionization mass spectra. The additive was identified as zinc pyrithione by comparison with authentic standard. Zinc pyrithione cannot be analyzed by GC-MS as it is. However, the thermal decomposition products of zinc pyrithione could be detected. The information on the decomposition temperature and products was useful for the identification of the original compound.

Gas Chromatography-Mass Spectrometry↗
PubMed2001

Automated on-line in-tube solid-phase microextraction followed by liquid chromatography/electrospray ionization-mass spectrometry for the determination of chlorinated phenoxy acid herbicides in environmental waters.

A method for the determination of six chlorinated phenoxy acid herbicides in river water was developed using in-tube solid-phase microextraction (SPME) followed by liquid chromatography/electrospray ionization-mass spectrometry (LC/ESI-MS). In-tube SPME is an extraction technique for organic compounds in aqueous samples, in which analytes are extracted from a sample directly into an open tubular capillary by repeated draw/eject cycles of the sample solution. Simple mass spectra with strong signals corresponding to [M-H]- and [M-RCOOH]- were observed for all herbicides tested in this study. The best separation of these compounds was obtained with a C18 column using linear gradient elution with a mobile phase of acetonitrile-water containing 5 mmol l-1 dibutylamine acetate (DBA). To optimize the extraction of herbicides, several in-tube SPME parameters were examined. The optimum extraction conditions were 25 draw/eject cycles of 30 microliters of sample in 0.2% formic acid (pH 2) at a flow rate of 200 microliters min-1 using a DB-WAX capillary. The herbicides extracted by the capillary were easily desorbed by 10 microliters acetonitrile. Using in-tube SPME-LC/ESI-MS with time-scheduled selected ion monitoring, the calibration curves of herbicides were linear in the range 0.05-50 ng ml-1 with correlation coefficients above 0.999. This method was successfully applied to the analysis of river water samples without interference peaks. The limit of quantification was in the range 0.02-0.06 ng ml-1 and the limit of detection (S/N = 3) was in the range 0.005-0.03 ng ml-1. The repeatability and reproducibility were in the range 2.5-4.1% and 6.2-9.1%, respectively.

Chromatography, Liquid↗
PubMed2001

Trace level determination of phenols as pentafluorobenzyl derivatives by gas chromatography-negative-ion chemical ionization mass spectrometry.

A method for the trace level determination of 11 phenols as pentafluorobenzyl (PFB) derivatives by gas chromatography-mass spectrometry (GC-MS) with negative-ion chemical ionization (NICI) is described. First, the conditions for the PFB derivatisation of phenols were optimized and were found to be reaction temperature 80 degrees C and reaction time 5 h. Second, the detection limits using selected ion monitoring (SIM) were compared between trimethylsilylated (TMS) derivatives in the electron ionization (EI) mode and PFB derivatives in the NICI mode. The responses for the PFB derivatives in the NICI mode were 3.3-61 times higher than those of the TMS derivatives in the EI mode. The instrumental detection limits using NICI-SIM ranged from 2.6 to 290 fg. This method was applied to the analysis of phenols in river water using solid-phase extraction. The recoveries of the phenols from a river water sample spiked with standards at 100 ng l-1 with 2-chlorophenol, 4-chloro-3-methylphenol and pentachlorophenol and at 1000 ng l-1 with phenol, 2,4-dimethylphenol, 2,4-dichlorophenol, 2-nitrophenol, 2,4,6-trichlorophenol and 4-nitrophenol were 81.2-106.3% (RSD 5.1-8.0%), except for 2-methyl-4,6-dinitrophenol and 2,4-dinitrophenol, for which the recoveries were 5.8 and 4.2%, respectively, because water contained in the acetone eluate interfered with the derivatisation of these compounds with two electrophilic nitro groups.

Gas Chromatography-Mass Spectrometry↗
PubMed2001

Determination of trace amounts of off-flavor compounds in drinking water by stir bar sorptive extraction and thermal desorption GC-MS.

A method for the determination of trace amounts of off-flavor compounds including 2-methylisoborneol, geosmin and 2,4,6-trichloroanisole in drinking water was developed using the stir bar sorptive extraction technique followed by thermal desorption-GC-MS analysis. The extraction conditions such as extraction mode, salt addition, extraction temperature, sample volume and extraction time were examined. Water samples (20, 40 and 60 ml) were extracted for 60-240 min at room temperature (25 degrees C) using stir bars with a length of 10 mm and coated with a 500 microm layer of polydimethylsiloxane. The extract was analyzed by thermal desorption-GC-MS in the selected ion monitoring mode. The method showed good linearity over the concentration range from 0.1 or 0.2 or 0.5 to 100 ng l(-1) for all the target analytes, and the correlation coefficients were greater than 0.9987. The detection limits ranged from 0.022 to 0.16 ng l(-1). The recoveries (89-109%) and precision (RSD: 0.80-3.7%) of the method were examined by analyzing raw water and tap water samples fortified at the 1 ng l(-1) level. The method was successfully applied to low-level samples (raw water and tap water).

Gas Chromatography-Mass Spectrometry↗
PubMed2000

Determination of nonylphenol ethoxylate oligomers by liquid chromatography-electrospray mass spectrometry in river water and non-ionic surfactants.

Liquid chromatography-electrospray ionization mass spectrometry (LC-ESI-MS) for the quantitative determination of five nonylphenol ethoxylate (NPE) oligomers in river water was described. These NPE oligomers were separated on a poly(vinyl alcohol) gel column using acetonitrile-30 mM ammonium acetate as the mobile phase followed by ESI-MS detection without any sample concentration steps. The sample was only filtered using the disposable filter and the aliquot (100 micro1) of this sample was injected into the LC-ESI-MS system. All NPE oligomers were detected using the [M+NH4]-ion. Detection limits ranged from 160 pg/ml (NPE4) to 240 pg/ml (NPE2), repeatability and reproducibility ranged from 4.2% (NPE2) to 6.2% (NPE6) and from 7.4% (NPE5) to 9.8% (NPE6).

Chromatography, Gel↗
PubMed1999

Analysis of anatoxin-a in freshwaters by automated on-line derivatization-liquid chromatography-electrospray mass spectrometry.

Anatoxin-a is a toxin produced from cyanobacterial blooms in freshwaters. In order to determine trace anatoxin-a in freshwaters, an automated on-line derivatization procedure with fluorenyl methylchloroformate using liquid chromatography-electrospray ionization mass spectrometry was developed. Anatoxin-a was extracted using solid-phase extraction with adequate recovery (75.7+/-7.2%, n=6) at 20 ng/l. The limits of quantification and detection were calculated to be 15.2 ng/l and 2.1 ng/l, respectively, using selected ion monitoring.

Bacterial Toxins↗
PubMed1997

Effect of an endothelin-1 antagonist, BQ-485, on cerebral oxygen metabolism after complete global cerebral ischemia in dogs.

Endothelin-1 (ET-1) plays an important role in the physiologic or pathophysiologic regulation of cerebral circulation. To evaluate the effects of the newly synthesized ETA receptor-selective antagonist, BQ-485 (N-perhydroazepin-l-ylcarbonyl-Leu-D-Trp-D-Trp-OH), on the cerebral metabolism of oxygen during the delayed cerebral hypoperfusion that follows global cerebral ischemia, we occluded the ascending aorta and caval veins of 10 beagle dogs for 12.5 min. The animals were randomized into two groups. BQ-485 was given directly into the carotid artery at 0.03 mg/kg per min for 30 min, starting 15 min after reperfusion in the treatment group (n = 5). Isotonic saline was infused in the control group (n = 5). A fiberoptic catheter was inserted into the superior sagittal sinus to monitor its oxygen saturation (SssO2) continuously. Arterial O2 content (CaO2), and sagittal sinus O2 content (CssO2) were monitored before and at 0.5, 1, 2, 4, 6 and 8 h after the ischemic insult. BQ-485 significantly prevented the expected decrease in SssO2 and increase in the cerebral O2 utilization coefficient at 4, 6 and 8 h after the ischemic insult (P < 0.05). Thus, BQ-485 ameliorated the mismatch between O2 supply and demand in the delayed hypoperfusion phase. We conclude that ET may be involved in the pathogenesis of delayed cerebral hypoperfusion after cardiac arrest.

Analysis of Variance↗
PubMed1997

The hemolytic uremic syndrome presenting as bilateral leg ischemia.

The hemolytic uremic syndrome in adults is an uncommon clinical entity consisting of microangiopathic hemolytic anemia, thrombocytopenia, and renal dysfunction. A previously healthy 42-year-old man, after a 2-day prodromal phase, developed severe pain and coldness in both legs, with purpura in the face and extremities. On admission, hepatorenal dysfunction and disseminated intravascular coagulation were evident. These complicated signs and symptoms led to nonspecific supportive therapy because of delayed diagnosis. The patient's condition gradually improved except for ischemia of the legs, which progressed into symmetrical necrosis; eventually, bilateral below-knee amputation was required. This is the first reported case of the hemolytic uremic syndrome complicated by bilateral leg ischemia. A presumed cause of the ischemia was disseminated intravascular coagulation, a rare complication of the hemolytic uremic syndrome.

Adult↗
PubMed1996

Firm myocardium in cardiopulmonary resuscitation.

Firm myocardium in cardiopulmonary resuscitation (CPR) is a rarely described yet potentially important condition. To investigate the clinical nature and implications of firm myocardium in CPR, we retrospectively analyzed 59 adult patients with nontraumatic out-of-hospital cardiac arrest who underwent open-chest CPR in the emergency department and had heart consistency recorded. Consistency of the myocardium varied considerably between patients. Firm myocardium was noticed in 36 cases, mainly in the left ventricle (firm myocardium group). The remaining 23 hearts were not firm (soft myocardium group). Some hearts had an increase in their consistency during CPR. Patient characteristics were similar in the two groups. The firm myocardium group showed greater base deficit on arterial blood gas analysis, suggesting more severe ischemic injury. Very firm heart had a close association with an extremely low end-tidal CO2 tension. Histopathological examination revealed hypertrophy and fibrosis common to the two groups. Both groups received similar treatment except for a shorter duration of direct cardiac massage in the firm myocardium group, although a reasonably prolonged effort was made in most cases. The firm myocardium group responded poorly to treatment. Very firm myocardium never contracted, whereas less firm myocardium usually showed some, albeit insufficient, activity. Most cases in the soft myocardium group regained a pulse. Our results suggest that firm myocardium: (1) is common in patients who receive CPR in the emergency department, (2) indicates ischemic contracture, (3) is not uniform in firmness, reflecting the degree of ischemia and (4) is a grave prognostic factor in cardiac resuscitation.

Adult↗
PubMed1995

Septic shock due to Pseudomonas aeruginosa in a previously healthy woman.

Pseudomonas aeruginosa septicemia rarely occurs in non-immunocompromised adults. We present a case of septic shock following Pseudomonas aeruginosa pneumonia in a previously healthy 48-year-old woman. The onset was sudden, with back pain, pyrexia and shock. Chest radiographs revealed pneumonia, and Pseudomonas aeruginosa was identified from blood and sputum cultures. Therapy with dopamine, piperacillin and fluid replacement led to a prompt recovery. Laboratory tests failed to reveal any immunological deficits. Including this case, only five cases of Pseudomonas aeruginosa septicemia in patients though to be non-immunocompromised have been reported. Two remarkable features of this type of Pseudomonas infection are apparent: i) it commonly develops from pneumonia and ii) it has a better prognosis than that in immunocompromised hosts.

Community-Acquired Infections↗
PubMed1993

The optimum timing of resuscitative thoracotomy for non-traumatic out-of-hospital cardiac arrest.

Open-chest cardiopulmonary resuscitation (CPR) is a promising method for non-traumatic cardiac arrest. In this preliminary study, we investigated the optimum timing of thoracotomy which brings high rate of return of spontaneous circulation (ROSC) and keeps the incidence of unnecessary thoracotomy minimal. Ninety-five adult patients with non-traumatic out-of-hospital cardiac arrest were analyzed. Of those, 26 patients were treated by the open-chest CPR in a prospective consecutive fashion. In this group, the ROSC rate was investigated in connection with the interval from hospital arrival, or ambulance call, to thoracotomy. Another 69 patients were treated by standard CPR. In this uncontrolled group, the interval from arrival at hospital to ROSC was investigated to define the 'natural hospital course' by the conventional treatment. Patient characteristics in the open-chest CPR group and the standard CPR group were similar. In the open-chest CPR group, 15 patients obtained ROSC. There was a tendency that the ROSC rate was highest in the patients with thoracotomy within 5 min of hospital arrival and declined as the timing of thoracotomy was delayed. Similar tendency was noted when the timing of thoracotomy was counted from the ambulance call. In the standard CPR group, only two patients obtained ROSC during the initial 5 min of hospital course. These results suggest that thoracotomy within 5 min of hospital arrival brings the highest ROSC rate while keeps the incidence of unnecessary thoracotomy acceptable.

Cardiopulmonary Resuscitation↗
PubMed1991

Hyperthermia following cardiopulmonary resuscitation.

To clarify the clinical nature of post-resuscitation hyperthermia, we reviewed the charts of 18 patients who had cardiac arrest on arrival and regained cardiovascular stability for a study period of sufficient length. Patients with trauma, burns, poisoning and cerebrovascular accidents were excluded. We analyzed the hyperthermia (above 38 degrees C) occurring in the initial 48 h after resuscitation. After resuscitation, most patients showed a rapid rise in body temperature. Patients with later brain death showed significantly earlier appearance of hyperthermia (6.2 h after cardiac resuscitation; median) and a higher peak temperature (39.8 degrees C; median) compared with patients showing prolonged coma (12.7 h and 38.3 degrees C, respectively). Hyperthermia above 39 degrees C was associated with subsequent brain death. The incidence of factors influencing body temperature did not differ between the brain death and prolonged coma groups. Patients achieving full recovery did not show hyperthermia. In conclusion, hyperthermia is an early indicator of brain damage after resuscitation.

Adolescent↗
PubMed1990

[Measurement of abundance ratio of 15N in amino acids by capillary gas chromatography-mass spectrometry].

A capillary gas chromatography-mass spectrometry for analysis of 15N-labeled amino acids and amides is described. The method is based on direct silylation of amino acids and amides with MTBSTFA and the formation of the TBDMS derivatives. The method was possible simultaneously to measure the 15N abundance ratio of amino-N and amide-N of amides, as to analysis of amino acids.

Amino Acids↗