Trying to develop an LCMS/MS method for oligonucleotides (dATP, dCTP, dGTP and dTTP) on HILIC (kinetex; 150×2.1mm, 2.6um) column. Gradient elution with 10mM aqueous ammonium acetate, pH-5.2 and ACN (starting with 90% organic) with a total run time of 10 minutes. Observing all oilgo standards at 3.8 min but the with poor peak elution pattern. Need suggestions to improve peak shape and even separation, if any. Thanks!!