Table 2: System suitability test results for the optimised HPLC method for determination of water-soluble vitamins in biological matrices (column temperature = 30°C; flow rate = 0.2 mL min−1). Mean peak areas of 5 injections of aqueous standard solution containing 20 ng mL−1 of each water-soluble vitamin.

VitaminRetention time (min)a (%CV)bCapacity factor (K′)Selectivity (α)Resolution ( 𝑅 𝑠 )Tailing factorplate countMean peak areas (mAU)c (%CV)b

C3.5 (0.9)1.721.202.880.793111365 (0.01)
B14.3 (0.7)2.211.152.650.774943170 (0.03)
B35.3 (1.1)2.791.173.130.80605693 (0.02)
B6 (PLP)6.1 (0.99)3.861.831.890.564255879 (0.001)
B56.8 (0.29)3.361.152.540.85705060 (0.05)
B913 (0.07)8.291.031.600.466735205 (0.01)
B1213.4 (0.6)8.571.031.270.422329740 (0.007)
B213.8 (0.2)8.861.071.300.4610962140 (0.001)

aThe retention time of unretained peak is 1.4 min.
b%Coefficient of variation.
cmilli Arbitrary Unit.