Table 4.
Experimental conditions and separation efficiencies of dipeptides in a spiral column with 1.6 mm ID coil with compressed in the 4 radial grooves at 800 rpm (Data obtained from non-compressed spiral column are shown in parentheses for comparison)
| Elution mode | Flow rate (ml/min) |
TP of 1st/2nd peaks | Rs | SF (%) |
|---|---|---|---|---|
| L-I-T (CCW) | 1 | 180/207 (127/93) | 3.55 (2.67) | 77.5 (77.0) |
| 2 | 490/222 (400/210) | 3.35 (2.67) | 60.0 (55.5) | |
| 3 | 514/292 (319/235) | 3.13 (2.39) | 47.2 (61.7) | |
| 5 | 476/443 (352/433) | 2.67 (2.17) | 39.4 (43.3) | |
| L-I-H (CW) | 1 | 206/125 (141/90) | 2.40 (2.05) | 52.0 (59.8) |
| 2 | 146/100 (112/76) | 1.93 (1.69) | 50.4 (53.2) | |
| 3 | 212/109 (120/67) | 1.88 (1.49) | 40.0 (46.3) | |
| 5 | 240/116 (131/63) | 1.65 (1.15) | 34.6 (37.9) | |
| U-O-T (CW) | 1 | 208/181 (141/133) | 1,92 (1.65) | 56.8 (34.2) |
| 2 | 176/145 (118/95) | 1.60 (1.27) | 50.4 (33.3) | |
| 3 | 207/189 (117/64) | 1.46 (0.95) | 53.4 (26.7) | |
| 5 | 243/162 (144/131) | 1.23 (0.83) | 31.4 (13.2) | |
| U-O-H (CCW) | 1 | 308/297 (237/263) | 3.92 (3.53) | 79.2 (74.1) |
| 2 | 414/355 (178/355) | 3.75 (3.12) | 74.6 (60.0) | |
| 3 | 576/425 (635/369) | 3.26 (3.26) | 55.0 (30.0) | |
| 5 | 1363/421(747/345) | 3.08 (2.40) | 47.3 (31.9) |
L-I-T: lower mobile phase pumped into the inner tail terminal; L-I-H: lower mobile phase pumped into the inner head terminal; U-O-T: upper mobile phase pumped into the outer tail terminal; U-O-H: upper mobile phase pumped into the outer head terminal; direction of rotation viewing the spiral disk :CCW, counterclockwise rotation; CW, clockwise rotation; TP: theoretical plate number; RS: peak resolution; SF(%); % stationary phase retention; 1st peak: val-tyr in L-I-T or L-I-H and trp-tyr in U-O-T or U-O-H; 2nd peak: trp-tyr in L-I-T or L-I-H and val-tyr in U-O-T or U-O-H.