121- STYROS® 2R Simulated-Monolith™ Polymeric Reversed Phase. Use of Narrow Bore column of 2.1 mm ID using high and low pH’s to separate Sulfa drugs and precursor 121- STYROS® 2R Simulated-Monolith™ Polymeric Reversed Phase. Use of Narrow Bore column of 2.1 mm ID using high and low pH's to separate Sulfa drugs and precursor