Determination of propionic acid and propionate in mixed feed additives by high performance liquid chromatog-raphy
An analytical method was developed for determining propionic acid and propionate(in propionic acid)in mixed feed additives by high performance liquid chromatography.Mixed feed additives were extracted using deionized water for 10 minutes under the ultrasonic assisted condition.After filtration with 0.45 μm membrane filter,the samples were separated by a C18 col-umn.Quantitative measurement was made at 210 nm using ultraviolet-visible detector.Critical contributory factors of determina-tion were discovered,including extraction time,extraction solvent,mobile phase pH.Under the experimental conditions,the limit of quantification(LOQ)for propanoic acid was 0.1%.Good linear relationship(R2≥0.999 9)was obtained between the peak area and mass concentration of propanoic acid when the propanoic acid accounted for 0.1%-20.0%in mixed feed additives.In addition,the method recovery ranged from 98.7%to 102%while the relative standard deviations(RSD)from 0.2%to 1.2%.This method was proven simple,accurate and reliable.It could be applied to the determination of propionic acid and propionate(in propionic acid)in mixed feed additives.
high performance liquid chromatography(HPLC)mixed feed additivespropionic acidpropionate