A high performance liquid chromatographic (HPLC) method was developed for the determination of naringin in milk and dairy products. Samples were extracted with methanol, and the analytes were separated on a C₁₈ column using a mobile phase consisting of 0.1% acetic acid aqueous solution and acetonitrile (75:25, V/V), detected by a diode array detector at 284 nm and quantified by an external standard method. The results showed that the linearity of this method was good in the concentration range of 5–500 μg/mL with a correlation coefficient of 0.9999. The recoveries of powdered and liquid milk power and yogurt spiked at 0.02, 0.04, and 0.08 g/100 g were 96.2%–103.2%, 96.3%–103.7%, and 99.7%–104.1%, respectively, with relative standard deviations (n = 6) of 1.12%–2.31%, 1.25%–1.85%, and 1.24%–1.66%, respectively. The reported method is simple, rapid, accurate, repeatable, and suitable for the determination of naringin in milk and dairy products.

A gas chromatographic (GC) method to determine the contents of 16 trans fatty acids in ice cream was established. The 2.0 g samples were pretreated sequentially with 8 mL of hydrochloric acid and 10 mL of anhydrous ethanol, separated on an SP-2560 capillary column, detected by GC with a flame ionization detector (FID) and quantified by the peak area normalization method. Under optimized chromatographic conditions, the limit of detection and limit of quantification of the proposed method were 0.012% and 0.024%, respectively, and it allowed effective separation of trans fatty acid methyl esters from cis fatty acid methyl esters and saturated fatty acid methyl esters.