BACKGROUND Urinary organic acids are water-soluble intermediates and end products of the metabolism of amino acids, carbohydrates, lipids, and a number of other metabolic processes. In the hereditary diseases known as organic acidurias, an enzyme or co-factor defect in a metabolic pathway leads to the accumulation and increased excretion of one or more of these acidic metabolites. Gas chromatog...

Biomass burning is becoming an increasing contributor to atmospheric particulate matter, and concern is increasing over the detrimental health effects of inhaling such particles. Levoglucosan and related monosaccharide anhydrides (MAs) can be used as tracers of the contribution of wood burning to total particulate matter. An improved gas chromatography-mass spectrometry method to quantify atmos...

RATIONALE To provide a simple one-step derivatization procedure for the analysis of a wide variety of amino acids in human hair by gas chromatography/combustion/isotope ratio mass spectrometry (GC/C/IRMS). N,O-Bis(trimethylsilyl)trifluoroacetamide (BSTFA) derivatization is already widely used outside the IRMS community, is applicable to a variety of functional groups, and provides products that...

Every infant born in the US is now screened for up to 42 rare genetic disorders called "inborn errors of metabolism". The screening method is based on tandem mass spectrometry and quantifies acylcarnitines as a screen for organic acidemias and also measures amino acids. All states also perform enzymatic testing for carbohydrate disorders such as galactosemia. Because the results can be non-spec...

background: urinary organic acids are water-soluble intermediates and end products of the metabolism of amino acids, carbohydrates, lipids, and a number of other metabolic processes. in the hereditary diseases known as organic acidurias, an enzyme or co-factor defect in a metabolic pathway leads to the accumulation and increased excretion of one or more of these acidic metabolites. gas chromato...

Background: Urinary organic acids are water-soluble intermediates and end products of the metabolism of amino acids, carbohydrates, lipids, and a number of other metabolic processes. In the hereditary diseases known as organic acidurias, an enzyme or co-factor defect in a metabolic pathway leads to the accumulation and increased excretion of one or more of these acidic metabolites. Gas chromato...

A mild, efficient and fast method for the trimethylsilyl (TMS), tetrahydropyranyl (THP) and methoxymethyl (MOM) protection of alcohols and phenols in the presence of sulfonated rice husk ash (RHA-SO3H) is reported. All reactions were performed at room temperature in high to excellent yields. All the products are separated and compared with authentic samples and/ or identified using different ty...