Maleic hydrazide has a pKa of 5.62 and a logP of -1.96. This logP value means it is very hydrophilic and will NOT retain well in Reversed Phase HPLC.

For this reason, we would suggest you try a method in Aqueous Normal Phase ANP using the Cogent Diamond Hydride™ column in order to retain it. The pKa of 5.62 suggests that a mobile phase additive of 0.1% formic acid would work best. And 0.1% TFA can also be investigated if detection is not done by MS.