Abstract:A resolved succinct environmental-friendly chromatography method was developed for determination of N-acetylneuraminic acid (Neu5Ac) and N-glycolylneuraminic acid (Neu5Gc) in bovine milk and products using high performance anion-exchange chromatography coupled with pulsed amperometric detection. The conditions affecting separation, detection, and sialic acid release from milk were optimized. The separation was finished on CarboPac PA20 anion-exchange column using 100 mM NaOH and 20-300 mM NaAc elution in 20 min at a flow rate of 0.5 ml min -1 . The separation and detection temperatures were both at 30°C. The detection was carried out on gold working electrode. The detection limits (25 l injection, three times of the baseline noise)were 3.0 and 1.8 g l -1 , and the linear range of 5-500 g l -1 was obtained. The spiked recovery of Neu5Ac and Neu5Gc in real samples was 88%-115%.

Sugars, alditols, and alcohols in tobacco products were quantified utilizing a method of high-performance anion-exchange chromatography-pulsed amperometric detection (HPAEC-PAD). The optimized analytical method can be used to classify different tobaccos and control the quality of tobaccos. To substantiate the applicability of the method, the analysis of 27 tobacco samples with satisfactory linearity, repeatability, and accuracy had been demonstrated. Compared with some other analytical methods for tobacco, the HPAEC-PAD method provided a simple and powerful tool for the analysis of not only sugars but also alcohols in tobacco extracts.