I am facing an issue with the stability of the synthesized hydroxamic acids, just after workup and silica gel column chromatography either a mixture of product or compound gets degraded with multiple spots, even without column purification compound gets degraded. Does in workup specific role of KHSO4 important ??? I don't have KHSO4, does any alternative is there ???

J. Am. Chem. Soc. 2021, 143, 37, 14962–14968, reference paper