The gradient started isocratically at 5% B for 3 min
and then increased to 75% in 6 min,then increased to 100% in 1 min,
remaining constant for 1 min and finally returning to 5% B in 1 min.
The oven temperature was 25 ◦C and the flow rate was 0.4 mL/min.
The injection volume was 50 L. All of the compounds were eluted
in less than 11 min.