A simple method for the simultaneous derivatization of carbohydrates, polyols, amines and amino acids using hexamethyldisilazane and N,O-bis(trimethylsilyl)trifluoroacetamide was developed. This method allows the direct derivatization of urine samples without sample pretreatment before derivatization. The method was successfully used for analysis of the selected metabolites in urine samples of healthy individuals and neonates suffering from galactosemia. The limits of detection by positive chemical ionization gas chromatography with tandem mass spectrometry analysis were in the range of 1.0 mgL-1 for mannitol to 4.7 mg/L for glucose.

• MeSH
• Algorithms MeSH
• Amines urine   MeSH
• Urinalysis MeSH
• Adult MeSH
• Galactosemias urine   MeSH
• Calibration MeSH
• Humans MeSH
• Limit of Detection MeSH
• Infant, Newborn MeSH
• Gas Chromatography-Mass Spectrometry MeSH
• Polymers analysis   MeSH
• Reproducibility of Results MeSH
• Carbohydrates urine   MeSH
• Tandem Mass Spectrometry MeSH
• Trimethylsilyl Compounds analysis   MeSH
• Freezing MeSH
• Check Tag
• Adult MeSH
• Humans MeSH
• Infant, Newborn MeSH
• Publication type
• Journal Article MeSH

Certain androstane steroids (AS) modulate ionotropic receptors, as do the pregnane steroids. Whereas women produce significant amounts of neuroactive progesterone metabolites, the steroid neuromodulators in men originate mainly from the 3-oxo-4-ene C(19)-steroids, which are converted to their 3alpha- and 3beta-hydroxy-5alpha/5beta-reduced metabolites. The neuromodulating effects of AS prompted us to monitor circulating levels of the steroids to estimate metabolic pathways in the periphery that may influence brain concentrations of AS. Hence, the serum levels of 20 steroids and 16 steroid polar conjugates including 17-oxo- and 17beta-hydroxy-derivatives of 5alpha/beta-androstane-3alpha/beta-hydroxy-androstane steroids were quantified in 15 men (16-62 years of age) using GC-MS. The conjugated AS for the most part reached micromolar concentrations, these being two or three orders of magnitude higher than those of the free steroids. The ratios of conjugates to free steroids were one to two orders of magnitude higher than the values for the corresponding pregnane steroids. This data suggested that conjugation may considerably restrain the transport of free AS from the periphery into the central nervous system.

• MeSH
• Androstanes chemistry   blood   MeSH
• Androstenedione chemistry   MeSH
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Adolescent MeSH
• Gas Chromatography-Mass Spectrometry methods   MeSH
• Pregnanes blood   MeSH
• Temperature MeSH
• Testosterone MeSH
• Pressure MeSH
• Trimethylsilyl Compounds analysis   MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Adolescent MeSH
• Male MeSH