Sensitive and simple determination of mannitol in human brain tissues by gas chromatography-mass spectrometry
ABSTRACT A simple, reliable and sensitive gas chromatographic-mass spectrometric method was devised to determine the level of mannitol in various human brain tissues obtained at autopsy. Mannitol was extracted with 10% trichloroacetic acid solution which effectively precipitated brain tissues. The supernatant was washed with tert.-butyl methyl ether to remove other organic compounds and to neutralize the aqueous solution. Mannitol was then derivatized with 1-butaneboronic acid and subjected to GC-MS. Erythritol was used as an internal standard. For quantitation, selected ion monitoring with m/z 127 and 253 for mannitol and m/z 127 for internal standard were used. Calibration curves were linear in concentration range from 0.2 to 20 microg/0.1 g and correlation coefficients exceeded 0.99. The lower detection limit of mannitol in distilled water was 1 ng/0.1 g. Mannitol was detected in control brain tissues, as a biological compound, at a level of 50 ng/0.1 g. The precision of this method was examined with use of two different concentrations, 2 and 20 microg/0.1 g, and the relative standard deviation ranged from 0.8 to 8.3%. We used this method to determine mannitol in brain tissues from an autopsied individual who had been clinically diagnosed as being brain dead. Cardiac arrest occurred 4 days later.
- SourceAvailable from: Akiko Shimamoto
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- "Biochemical diagnoses of brain death greatly aid forensic specialists and clinical staffs . We evaluated brain levels of various therapeutic drugs in patients with brain death     . For example, cerebral concentrations of mannitol, an anti-edema reagent, alters as the time of administration in a rodent model . "
ABSTRACT: In anaesthetized, mechanically ventilated rats with brain death induced by epidural balloon inflation, we assessed the levels of cerebral myo-inositol in three brain areas 4 h after brain death had been confirmed. The levels were measured using HPLC, along with the water content. Myo-inositol levels were significantly increased in the cerebellum (P<0.05) and decreased in the brainstem (P<0.001), compared to findings in controls. Such changes can serve as hallmarks of brain death.Legal Medicine 04/2005; 7(2):110-2. DOI:10.1016/j.legalmed.2004.08.006 · 1.44 Impact Factor
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- "Tomiya et al.  reported that some sugar alcohols such as sorbitol and myo-inositol were detected as endogenous compounds in rat tissues. We also found sorbitol in human tissues . Since phenylisocyanate derivatives of mannitol were not completely separated from that of sorbitol , we selected p-nitrobenzoyl chloride as derivatizing reagent. "
ABSTRACT: A method for simultaneous determination of glycerol and mannitol in various human tissues was devised and for this we used high-performance liquid chromatography (HPLC). Specimens were homogenized in a mixture of chloroform and methanol, phosphate buffer (pH 7.0) and pentaerythritol (IS) solution. After centrifugation, an aliquot of the aqueous layer was evaporated to dryness and derivatized with p-nitrobenzoyl chloride at 50 degrees C for 1h, then applied to HPLC with analytical conditions of: column, CAPCELL PAK C18 MG (250 mm x 3.0 mm i.d., 5 microm, Shiseido Co. Ltd., Tokyo, Japan); column temperature, 1-2 degrees C; mobile phase, 75% acetonitrile-distilled water containing 0.05% trifluoroacetic acid, 0.05% heptafluoro-n-butyric acid and 0.1% triethylamine; flow rate, 0.5 ml/min; wavelength, 260 nm. Calibration curves for both substances were linear in concentration ranges from 1 to 500 microg/0.1g and correlation coefficients exceeded 0.99. The relative standard deviation (R.S.D.) of the method was evaluated at concentrations of 10 and 100 microg/0.1g, and ranged from 0.84 to 10.6%. Using this method, we determined the regional distribution levels of glycerol and mannitol in various tissues from an autopsied brain dead man.Forensic Science International 03/2002; 125(2-3):127-33. DOI:10.1016/S0379-0738(01)00624-7 · 2.12 Impact Factor