HPLC-UV determination of Tween 80 in pharmaceutical preparations on a CHROMSHELL® C18-XB 2.6 µm column, 100 mm × 4.6 mm, part number CSH-5749-GI46. The mobile phase composition and the column temperature are declared proprietary in the note and are therefore not disclosed; no gradient programme or flow rate is given. Injection volume 2.5 µL, UV detection at 195 nm. Single analyte: Tween 80, no CAS number given. The note is built around a direct column comparison: on the CHROMSHELL® column the test solution gives the Tween 80 peak marked 1 at about 4.1 min as a tall, sharp and symmetrical peak, whereas the same test solution on a competitive SPP column gives a markedly lower and broader peak at about 4.8 min. The text states that CHROMSHELL® C18-XB provides a good tailing factor…