ELECTROSPRAY MASS-SPECTROMETRIC DETECTION OF CHITOBIOSE IN ENZYME HYDROLYSATES OF MARINE-PHYTOPLANKTON

The presence of chitin in algae was determined by mass spectrometric d etection of its enzymatic hydrolysis end product, chitobiose. Electros pray mass spectrometry (ES-MS) was used for detection of chitobiose in the enzyme hydrolysate because of its capability to detect underivati zed amino sugar oligomers. This strategy affords simplified sample pre paration and reduced processing time. Despite the remarkable success i n the analysis of purified sugars, ES mass spectrometric detection of sugars in complex matrices remains a challenging task and generally re quires sample cleanup. This work demonstrates the use of ES-MS with bo th off-line and on-line sample cleanup for the detection of chitobiose generated by the enzymatic hydrolysis of chitin. The porous graphitic carbon (PGC) packing material used in the on-line method has been use d for chromatographic separation of sugars and is particularly suitabl e for this assay because ES-compatible solvents such as water and acet onitrile can be used for analyte elution. The effectiveness of microsc ale liquid chromatography ES-MS with PGC was demonstrated for a suite of sugars.