| Hydrogen sulfide （H2S） is a highly toxic environmental pollutant. Determinationof H2S in the environment is an important health monitoring item. It has been recentlydiscovered that endogenous H2S is the third biological messenger molecule. That’svery necessary that the concentration is accurately detected on the endogenousgeneration of the H2S, biological effects of H2S donor, and the pathophysiology of themeaning of a wide range of research work. And there are many difficulties applicationof existing detection methods. It is great significance to carry out detection methodresearch of biological messenger molecule H2S.Melamine （MM） is a raw material in the chemical industry, and it can turn intoinsoluble salt and urinary tract stones in the human body. That serious harm humanhealth.MM has been illegally used food additives in recent years, because of false toimprove the protein content of dairy products. A severe emergency had been causedby it. Detection of MM in the food has become highly concerned about food safetywork.In the chapter2, based on the inhibition of endogenous H2S on the fluorescenceintensity of fluorescein mercury, the highly sensitive fluorescence quenchingdetection method had been developed for the biological messenger molecule ofhydrogen sulfide. In the KH2PO4-K2HPO4buffer solution system, the hydrogensulfide form mercuric sulfide with mercury, resulting in fluorescence quenching offluorescein mercury. In the optimal reaction conditions, in2.32×10-71.05×10-6mol/Lrange, The fluorescence quenching intensity was linear to the hydrogen sulfide concentration. The regression equation ΔF=29.04c+6.89(c:10-7mol/L), r=0.9986and detection limit of6.97×10-8mol/L. The sample recoveries was91.47%to106.84%.The method was sensitive, easy to operate, and the determination of hydrogensulfide for biological messenger with satisfactory results.In the chapter3, endogenous H2S was absorbed with NaOH solution, and theformation of the S2-generate the HgS because it react with Hg2+-2-PBI, the2-PBIwas released.The test system produce fluorescence. Determination of thefluorescence intensity, the biological messenger molecule hydrogen sulfide content inthe samples was examined according the standard quantificational curve. Establisheda new method of fluorescence spectrophotometric detection of biological messengermolecule hydrogen sulfide.Under the optimized experimental conditions, in6.39×10-73.64×10-6mol·L-1concentration range, system of F value and H2S concentrations between linearrelationship for the delta ΔF=71.33c-3.6228(c,10-6mol·L-1), r=0.9991. In11blank measurement value of3times the standard deviation divided by the slopecalculation of detection limit of1.92×10-7mol·L-1. Cell culture fluid samples fordetermination of the relative standard deviation is0.28%0.94%, and the recoveryrate was97.2%103.1%.The method was sensitive, simple operation, low analysiscost, used for biological messenger molecule H2S determination, with satisfactoryresults.In the chapter4, cresyl violet perchlorate in the BR buffer solution-CPCsurfactant media was synchronous scaned. The resonance fluorescence characteristicsof the synchronous scanning spectrum was analysed using three-dimensionalfluorescence and absorption spectra; based on melamine-cresolinhibition of resonancefluorescence intensity of the violet perchlorate, a new method of inhibition resonancefluorescence analysis was developed for determination of melamine.9.6×10-82.8×10-6mol·L-1concentration within the system ΔF values with melamine concentrationbetween a good linear relationship, linear regression equation was ΔF=106.59c-5.44and (c,10-6mol·L-1), the correlation coefficient r=0.9993. The detection limit was2.87×10-8mol·L-1. Milk samples and the relative standard deviation of1.9%to2.7%, the recovery rate was95.0%103.1%. The method was sensitive, easy to operate,low-cost. It was satisfactory results for the determination of melamine in milk powderwith. |
PDF Full Text Request