| 1. Study on the measurement method for intestinal permeability by high performance liquid chromatography with evaporative light scattering detector.Urinary excretion of nonmetabolized sugars, such as lactulose/mannitol in urine samples, has been widely used as a noninvasive method to assess intestinal permeability. This test has been used in clinical practice for the estimation of intestinal permeability in patients with HIV infection, hepatic cirrhosis, coeliac diseases, pancreatitis, organ transplantation, digestive tumor, food allergy and surgery such as adustum, shock and bone fracture.A HPLC-ELSD method was established for the determination of lactulose(L)/ mannitol(M) excretion ratio in urine samples. L and M was separated on an Alltech prevail carbohydrate column (250mm×4.6 mm, 5μm). The mobile phase consisted of acetonitrile-H2O (8:2) and the flow rate was 1.0ml/min.The detector tube temperature was 86℃. The flow rate of carrier gas was 1.5ml/min. The value of gain was 4 and the impactor was turn off.The results showed that the linear range of mannitol and lactulose was repectively 20～960mg/L (r=0.9973) and 25～800mg/L (r=0.9962).The inter-day precision was 1.5% for mannitol and 1.3% for lactulose. The average recovery was 94.4% for mannitol and 95.0% for lactulose. Detection limit of mannitol and lactulose was 200ng and 250 ng, respectively. A siganificant rise in 6-hour urinary L/M excretion ratio was found in cirrhosis patients with ascites (0.40±0.34) compared to that of control subjects (0.025±0.005).The determination of the L/M excretion ratio by HPLC-ELSD may be a presice, simple, convenient and noninvasive method to evaluate intestinal barrier function in clinical practice. The examination of intestinal barrier for critical patients will reduce the incidence rate of systemic inflammatory response syndrome (SIRS) and multiple organ dysfunction syndrome(MODS).2. Study on the measurement method by headspace gas chromatography for organic residues in the extract of traditional Chinese drug, which was processed with macroporous resin. Macroporous resin was a kind of high molecular polymer and usually taken as a means of separating and purifying Chinese traditional drug. However, almost all of them were chemical resins, which contained harmful organic sovlents. To ensure the safety of productions, we had to examine the organic residues in the extract of traditional Chinese drug. We established a Headspace Gas Chromatography method to determinate organic residual solvents in the extract of traditional Chinese drug, such as n-Hexan, benzene, methylbenzene, 1,4-Dimethylbenzene, Styrene, 1-2-Diethylbenzene, Divithylbenzene, Naphthalene. We studied and optimized the chromatographic conditions, such as temperature programming, vials equilibrium temperature, vials equilibrium times, pressurize time, loop fill time, loop equilibrium time and loop inject time, etc. The GC system consisted of DB-624 capillary chromatographic column, N2 as the carrier gas, FID as the detector. Initial temperature was set at 80℃and stayed for 1 min. It was programmed rising by 10℃/min until 240℃and stayed for 1 min. Flow rate of carrier gas was 1.5 mL/min. Inject temperature was 280℃. Detector temperature was 250℃. Vials equilibrium temperature was 70℃. Vials equilibrium time was 60min. Loop fill time was 2min. Loop equilibrium time was 1min. Inject time was 1min. Vials were not pressurized.The results showed that the residual solvents had a good linearity in the experimental concentration(r: 0.9976～0.9999). The inter-day precision was less than 5%. The recovery was ranged from 82.8%～103.7%. The detection limit was ranged from 0.098～1.06 ng/ml. The extract of traditional Chinese drug was examinated to contain n-Hexan, benzene and methylbenzene. The Amount of n-Hexan, benzene and methylbenzene accord with government standard, which was 0.35, 0.29,0.18μg/g, respectively. We can believe the Macroporous resin was safe and reliability for separating and purifying traditional Chinese drug.
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