Substitution
of hydroxyl groups by volatile trimethylsilyl (TMS) groups has enlarged the application of gas-liquid chromatography (GLC) in the analysis of carbohydrates. In the past two years this technique has been extended to the acid-stable (l-3) and unstable (2, 3) sugar phosphates and has now been applied to the sugar nucleotides. In this report are described the preparative purification of glucose 6-phosphate by GLC and some of the properties of the TMS derivatives of aldose l-phosphates and sugar nucleotides isolated by GLC.
MATERIALS AND APPARATUS
Except as noted the sugar phosphates and nucleotides were commercial preparations. The trimethylsilylation reagent was prepared by the addition of 1 ml trimethylchlorosilane and 1 ml hexamethyldisilazane to 5 ml anhydrous pyridine. A slight turbidity was removed by centrifugation, which gave a supernatant stable indefinitely in a stoppered vial. Both silicon compounds were obtained from Applied Science Laboratories, Inc., State College, Pa. The column packing was made by combining Chromosorb W Regular (SO-SO mesh) with a toluene solution of SE-30 (methyl) silicone gum rubber, leaving a 3% coating after evaporation of the solvent. Both column components were products of Wilkens Instrument and Research, Inc., Walnut Creek, Cal. The coated support was packed in the 6' X j/,#? U-shaped column of a Barber-Colman model 10 gas chromatograph with an argon-gOSr ionization detector operated at 5OOV and 250". At an input pressure of 18 psi the gas flow measured 200 ml/min at the exit port. Samples were injected at 225".