[Determination of nicacid and its metabolites in human plasma by HPLC-MS/MS].

Objective: To develop a sensitive HPLC-MS/MS method for the determination of nicacid and its metabolites in human plasma.

Methods: The assay was conducted with an API 3000 LC-MS/MS system comprising of a Genimi C18 column (50 x 3.00 mm, 3 microm), and an eluate of 0.1% acetic acid-methanol-isopropyl alcohol (98: 1:1), and flow rate was 0.2 mL/min. Acetonitrile was used to precipitate protein from the plasma samples. The loading samples contained the residue from the supernatant that were dissolved in the eluate solution and rinsed by dichloromethane was used as the loading samples. The ion pairs of m/z 124.1-->80.0, m/z 123.1-->80.0, m/z 181.1-->135.0 and m/z 138.1-->92.0 were used to quantify nicacid, niacinamide, nicotinuric acid and 6-methyl nicotinic acid (IS), respectively.

Results: The standard curves of nicacid, niacinamide and nicotinuric were linear in the range of 1.25-320 microg/L, 1.25-1280 microg/L and 1.25-1280 microg/L, respectivly. All with a low determination limits of 1.25 microg/L and a less than 9% within-day and inter-day RSD. The recovery rates reached 89% to 105%.

Conclusion: The method is simple, rapid, sensitive, and suitable for the determination of nicacid and its metabolites in human plasma.