Dispersive solid-phase extraction based on zirconium metal-organic framework coupled with gas chromatography-mass spectrometry for determining sugar phosphates in biological samples.

BACKGROUND: Sugar phosphates (SPx) play important role in the metabolism of the organism. SPx such as glycerate 3-phosphate, fructose 6-phosphate and glucose 6-phosphate in biological samples have the poor stability, similar structure and low abundance, which make their separation and detection more challenging. METHOD: UiO-66-NH2 and ZrO2 coated SiO2(SBA-15) hard-core-shell adsorbents (UiO-66-NH2@SBA-15 and ZrO2@SBA-15) were synthesized, which were further used for dispersive solid-phase extraction for enriching the SPx in biological samples. The protocol was developed by UiO-66-NH2@SBA-15 and ZrO2@SBA-15 coupled with gas chromatography-mass spectrometry for the detection of trace SPx. The univariate experiment and response surface methodology were used to optimize the adsorption and desorption conditions. RESULTS: The adsorbents showed excellent adsorption capacity and specificity towards SPx, which were proved by adsorption and selective experiments. Under the optimized conditions, there were good linearity within the range of 5.0-5000.0 ng mL-1, low limits of detection (0.001-1.0 ng mL-1), low limits of quantification (0.005-5.0 ng mL-1) and good precision (relative standard deviation less than 14.7 % for intra-day and inter-day). The satisfactory recoveries (89.1-113.8 %) and precision (0.5-14.6 %) were obtained when the sorbents were used to extract SPx from serum, saliva and cell samples. Moreover, UiO-66-NH2@SBA-15 was applied to the quantitative analysis of SPx from gastric cancer patients, because of a higher adsorption capacity (169.5-196.1 mg g-1). CONCLUSIONS: UiO-66-NH2@SBA-15 showed great potential in the extraction of SPx in biological samples, which was beneficial to find out the metabolic change of SPx and explain the pathogenesis of the disease.

[Comparison of the effects between maize germ oil and lard oil loading on blood lipids and fatty acid profile of mice].

OBJECTIVE: To investigate the changes in blood lipids and fatty acids profile of mice after different oil loading, and explore the effects of different dietary fatty acids on postprandial blood lipids and fatty acid profile. METHODS: Ninety-six C57BL/6 mice were randomly divided into 2 groups by weight ,maize germ oil group and lard oil group. The mice were given maize germ oil or lard oil by gavage at a dose of 1 ml/100 mg BW, respectively, after over-night fasting. At 0, 30, 60, 120, 180 and 240 min after oil loading, 8 mice were selected randomly from both groups, respectively, and blood was collected via orbital bleeding for postprandial blood lipids and fatty acid profile analysis. RESULTS: The serum triglycerides and total free fatty acids levels in mice loaded with lard oil were significantly higher than those in mice loaded with maize germ oil, respectively, at 120, 180, 240 min. The serum saturated fatty acids and monounsaturated fatty acids in mice loaded with lard oil were significantly higher, whereas serum polyunsaturated fatty acids were significantly lower than those in mice loaded with maize germ oil at 60, 120, 180 and 240 min (P < 0.05). Serum palmitic oil and oleic oil in mice loaded with lard oil were higher, whereas linoleic oil and arachidonic acid were lower than those in mice loaded with maize germ oil at 60, 120, 180 and 240 min (P < 0.05). CONCLUSION: Compared with maize germ oil, lard oil leads to higher postprandial serum triglycerides and saturated fatty acids levels, that may increase the risk of cardiovascular diseases.