Method for compound with -COOH and -OH

[Lucy]

If one compound has both -COOH and -OH functional group, under acid condition it will have lactonization, what HPLC method is preferred?

[HW Mueller]

If your compound only has these two fuctional groups and if it indeed forms the lactone easily, and if the lactone is thermodynamically favored, and if you don´t need the ratio of the lactone to acid, you could convert it to the lactone and try a HPLC method without a buffer.