Establishment of an in vitro fluorescence spectrophotometry based on end-product malondialdehyde for evaluating scavenging ability on hydroxyl radicals / 中国药理学通报

Aim To establish an in vitro fluorescence spectrophotometry based on the end-product malondialdehyde(MDA)for evaluating hydroxyl radical-scavenging ability, and compare the advantages and disadvantages of fluorescence and visible methods.Methods The reaction time, temperature, and the concentration of key reactant deoxyribose were investigated and optimized respectively.Under different solvent conditions, sensitivity and the measurement window of two methods were compared.The hydroxyl radical scavenging ability of tanshinone I was determined by these two methods.Results The optimal temperature and time was 37 °C and 60 min, and the concentration of deoxyribose was 2.8 mmol·L-1.The limit of detection for the fluorescence method(4.49 nmol·L-1)was much lower than that of the visible spectrophotometry(39.15 nmol·L-1).The ratio of model/control(the measurement window)of the fluorescence method was much larger than that of visible spectrophotometry in both the aqueous system and the organic system(containing DMSO).Within the concentrations of 62.5 mg·L-1-1 000 mg·L-1, tanshinone I showed scavenging ability on hydroxyl radicals in a concentration-dependent manner using the fluorescence method, but the visible method could not.Conclusions In contrast to visible method, fluorescence method has the advantages of higher sensitivity and stronger anti-interference ability to the color of test substance and the specificity of solvents.By virtue of large measurement window, it can be applied to evaluating the effect of fat-soluble test substances.

Detection of tin in human urine by atomic fluorescence spectrophotometry / 中国职业医学

OBJECTIVE: To establish a method for determination of urinary tin by atomic fluorescence spectrophotometry.METHODS: The graphite digestion instrument was used to digest 2. 50 m L urinary sample with 1. 50 m L concentrated nitric acid,hydrochloric acid( volume fraction 4. 00%) was added to a total constant volume of 10. 00 m L. After 2. 50 m L of thiocarbamide-ascorbic acid( mass concentration 100 g / L) was added,hydrochloric acid( volume fraction 4. 00%) was added to a total constant volume of 25. 00 m L( equivalent to urinary sample was diluted 10 times),1. 00 m L of the sample was collected and detected by atomic fluorescence spectrophotometry. RESULTS: The good linear relationship was shown in the range of 4. 00-200. 00 μg / L with a correlation coefficient of 0. 999 5. The limit of detection was 0. 20 μg / L. The recovery rates ranged from 100. 20% to 100. 84%. The within-run relative standard deviation( RSD) and between-run RSD were 0. 11%-2. 01% and 1. 37%-5. 58%,respectively. The samples can be stored for 7 days under the temperature of4 ℃. CONCLUSION: This method has the advantages of high sensitivity,precision and convenient operation,which is suitable for the daily determination of urinary tin in human.

Study on inclusion process of decomposed volatile oil from Atractylodes macrocephala with hydroxypropyl-β-cyclodextrin / 中草药

Objective: To optimize the inclusion process of decomposed volatile oil from Atractylodes macrocephala (DVOA) with hydroxypropyl-β-cyclodextrin (HP-β-CD). Methods: The inclusion complex was prepared by the freeze drying method. The preparation process was evaluated using fluorescence spectrophotometry. The inclusion process conditions were screened by the orthogonal test, with the inclusion ratio and oil ratio as indexes, and mass ratio between HP-β-CD and DVOA, inclusion temperature and inclusion time as the impacting factors. The inclusion complex was characterized through ultraviolet-visible spectra (UV-vis), fluorescence spectra (FL) and microscopic imaging, and the stability test was performed. Simultaneously, the chemical composition in DVOA before and after inclusion was analyzed by GC-MS technique. Results: The DVOA and HP-β-CD had formed inclusion complex, the optimal inclusion conditions were as follows: The mass ratio of HP-β-CD to DVOA was 10:1, the inclusion temperature was 30℃, the inclusion time was 2.0 h, and the ratios of average inclusion and oil were 73.32% and 10.43%, respectively. The chemical composition of DVOA was consistent before and after inclusion, the inclusion just had the slight effects on proportion of each component. Conclusion: The preparation process of DVOA/HP-β-CD inclusion complex under the optimal conditions is reasonable, stable, and feasible, and can provide the reliable experimental basis for the anti-tumor new drug research and development of DVOA.

Detection of Artifical Antigen for Cd by Fluorescence Spectrometry / 分析化学

Artificial antigen Cd-IEDTA-BSA (HSA) was successfully synthesized by the bifunctional chelating agent IEDTA (isothiocyanobenzylethyl enediamine tetraacetic acid) coupling with cadmium and protein carrier. The fluorescence characteristics of antigen were determined by fluorescence spectrophotometry and the coupling ratio 11∶ 1-16∶ 1 was obtained for the coupling reaction. The folding status of serum albumin during the synthesis process of artificial antigen Cd-IEDTA-BSA (HSA) was analyzed using "fluorescence phase diagram", and the result shows that it was conformed to the "all-or-none" pattern. The polarization fluorescence spectra show that the microenvironments of tryptophan residues in carrier protein have some changes to cause changes in protein conformation.

Determination of Berberine Hydrochloride in Coptis chinensis Franch.and Xianglian Pills by Thin Layer Chromatograph-Fluorescence Spectrophotometry Method / 中国中医药信息杂志

Objective To establish a determining method for the content of berberine hydrochloride in Coptis chinensis Franch.and Xianglian pills.Method The sample was extracted and developed,the berberine hydrochloride was determined by thin layer chromatograph-fluorescence of spectrophotometry with Benzen-ethylaceate-isopropanol-methanol-ammonia water(6:3:1.5:1.5:0.5) as the developing system and Ex=365 nm,Em=409 nm.Result The calibration curve was linear in the range of 0.473～ 3.784 ?g,r=0.999 3.The recovery rate in Coptis chinensis Franch.was 99.03%,RSD=1.86%,and in Xianglian pills was 97.10%,RSD=1.09%.Conclusion The method is simple and accurate.

Determination of riboflavin in salive / 中国药学杂志

OBJECTIVE:To observe the correlation of concentration-time curves of riboflavin in salive and plasma.METHOD:After peple orally taking riboflavin tablets,the riboflavin in salive was determinated by fluorescence spectrophotometry with excitation wavelength 475.4nm and emission wavelength 524.7nm.RESULTS:The recovery of riboflavin was over 96%.The detection limits of riboflavin was 5ng.ml-1,and the calibration curve was linear in the range of 5ng.ml-1～3μg.ml-1.The regression equation was △F′=0.116c+0.232(r=0.9999).CONCLUSION:The concentration-time curves of riboflavin in salive was similar to these in plasma.

Applicationof opticalanalysis measurements to medical analysis instrument / 医疗卫生装备

This paper describes the basic principles of optical analysis measurements,such as colorimetry,spectrophotometry,fluorometry,fluorescence spectrophotometry and scatter,and their typical applications to medical analysis instrument.The quality control of the optical analysis instrument and their development are also discussed.