D-Mannose in human serum, measured as its aldononitrile acetate derivative

We report a procedure for determining D-mannose in serum. After removal of proteins and lipids, the carbohydrate-containing fraction is treated to form the aldononitrile acetate derivative and analyzed by gas--liquid chromatography with a flame-ionization detector. D-Mannose and D-glucose had retention times of 31 and 34 min, respectively. Day-to-day reproducibilities (CV) of between 2 and 12% for mannose were attainable for quantities of 100--900 ng. Related hexoses and derivatives do not interfere. The sensitivity was such that 10 mg/L could be detected in a 0.1-mL sample of serum. This method may be of use in diagnosing invasive Candida infection.