According to the Japanese Pharmacopoeia (JP XVII*), “Assay" for “Lactulose" should be carried out with a column filled with strong acidic ion-exchange resin. The SUGAR SP0810 confirmed the requirements were met.
"In the JP, the column length is specified as 50 cm. The column length of the SP0810 is 30 cm, but it fully meets the system suitability requirements. (As long as a column meets the system suitability requirements, the use of a different column length is allowed.)"

System suitability requirementsElution order (Stadandard solution 10 µL inj.): lactulose, the internal standard (mannitol)
Resolution between lactulose and the internal standard (Stadandard solution 10 µL inj.): ≥ 8
Relative standard deviation (RSD) of the ratios of the peak heights of lactose, lactulose, and galactose to the peak height of the internal standard (Stadandard solution 20 µL inj.): ≤ 2.0% (repeated 6 times)

*The version at the time of the application acquisition.

Sample: 10 µL
(Standard solution) 10 mg/mL each of Lactulose and D-Mannitol, 1.6 mg/mL of Galactose and 0.8 mg/mL of Lactose in H₂O

1. 1.Lactose
2. 2.Lactulose
3. 3.Galactose
4. 4.Mannitol