In this work, a novel method was constructed to determine the enantiomeric composition of tryptophan （Trp） by bovine serum albumin （BSA） based on the fluorescence spectra of the receptor-ligand mixtures coupled wi...In this work, a novel method was constructed to determine the enantiomeric composition of tryptophan （Trp） by bovine serum albumin （BSA） based on the fluorescence spectra of the receptor-ligand mixtures coupled with partial least squares （PLS-1） analysis. As a result the enantiomeric composition of Trp was accurately determined.展开更多
The fluorescence property of europium(Ⅲ)-doxycycline(DC) complex and the effect of reaction condition were studied. It is found that in the buffer solution of Na_2B_4O_7-NaOH at pH 9.63 europium can react with doxycy...The fluorescence property of europium(Ⅲ)-doxycycline(DC) complex and the effect of reaction condition were studied. It is found that in the buffer solution of Na_2B_4O_7-NaOH at pH 9.63 europium can react with doxycycline to form a complex. After intramolecular energy transfer, the system shows the characteristic fluorescence of Eu 3+. The fluorescence intensity can be enhanced again in addition of non-ionic surfactant Triton X-100 with λ_ ex=375 nm, λ_ em=617 nm. Based on this, a new method using europium ion as fluorescent probe for the determination of trace doxycycline was proposed. The fluorescence intensity is linearly related to the doxycycline concentration in the range of 2.8×10 -6～2.46×10 -5 mol·L -1 with correlation coefficient 0.9973. The detection limit was 1.35×10 -8 mol·L -1. It is applied to the determination of doxycycline in pharmaceutical preparations and in serum satisfactorily. The recovery is within the range of 93%～103%.展开更多
Facial mask is a kind of skin care cosmetics, in which fluorescent whitening agents（FWAs） were added to make face skin look whiter and brighter. In this work, pig skin was used instead of human skin to test the meth...Facial mask is a kind of skin care cosmetics, in which fluorescent whitening agents（FWAs） were added to make face skin look whiter and brighter. In this work, pig skin was used instead of human skin to test the methods. Three methods, including pig skin migration fluorescent spectrophotometry（FS）, fiber paper migration FS, and fiber paper migration visual colourimetry（VC）, were developed for determining the migration amount of FWAs from facial mask to pig skin. In the methods, a self-assembly light source and fluorescence collecting unit was used. The unit can be easily moved and the measurement was very convenient. Some experimental conditions were optimized. The fiber paper migration VC can give semi-quantitative results and was the simplest one in the three methods because collec- tion, separation and detection of the fluorescence were not needed. Both the pig skin migration FS and fiber paper migration FS can give quantitative results and compared with fiber paper migration FS, the pig skin migration FS could give more practical results by simulating the real way of using facial mask. The limits of detection for disodium 4,4＇-bis[（4-anilino-6-hydroxyethylamion-1,3,5-triazin-2-yl）amion]stilbene-2,2＇-disulphonate（VBL） obtained by pig skin migration FS and fiber paper migration FS were 0.03 and 0.05 mg/m2, respectively. 96 kinds of samples were analyzed and the migration amounts of FWAs in 21 kinds of samples were detectable. Correlations between migration amounts obtained by the three methods were very good. Experimental results indicate that the present methods can be applied to the determination of migration amount of FWAs in facial masks.展开更多
文摘In this work, a novel method was constructed to determine the enantiomeric composition of tryptophan （Trp） by bovine serum albumin （BSA） based on the fluorescence spectra of the receptor-ligand mixtures coupled with partial least squares （PLS-1） analysis. As a result the enantiomeric composition of Trp was accurately determined.
文摘The fluorescence property of europium(Ⅲ)-doxycycline(DC) complex and the effect of reaction condition were studied. It is found that in the buffer solution of Na_2B_4O_7-NaOH at pH 9.63 europium can react with doxycycline to form a complex. After intramolecular energy transfer, the system shows the characteristic fluorescence of Eu 3+. The fluorescence intensity can be enhanced again in addition of non-ionic surfactant Triton X-100 with λ_ ex=375 nm, λ_ em=617 nm. Based on this, a new method using europium ion as fluorescent probe for the determination of trace doxycycline was proposed. The fluorescence intensity is linearly related to the doxycycline concentration in the range of 2.8×10 -6～2.46×10 -5 mol·L -1 with correlation coefficient 0.9973. The detection limit was 1.35×10 -8 mol·L -1. It is applied to the determination of doxycycline in pharmaceutical preparations and in serum satisfactorily. The recovery is within the range of 93%～103%.
文摘Facial mask is a kind of skin care cosmetics, in which fluorescent whitening agents（FWAs） were added to make face skin look whiter and brighter. In this work, pig skin was used instead of human skin to test the methods. Three methods, including pig skin migration fluorescent spectrophotometry（FS）, fiber paper migration FS, and fiber paper migration visual colourimetry（VC）, were developed for determining the migration amount of FWAs from facial mask to pig skin. In the methods, a self-assembly light source and fluorescence collecting unit was used. The unit can be easily moved and the measurement was very convenient. Some experimental conditions were optimized. The fiber paper migration VC can give semi-quantitative results and was the simplest one in the three methods because collec- tion, separation and detection of the fluorescence were not needed. Both the pig skin migration FS and fiber paper migration FS can give quantitative results and compared with fiber paper migration FS, the pig skin migration FS could give more practical results by simulating the real way of using facial mask. The limits of detection for disodium 4,4＇-bis[（4-anilino-6-hydroxyethylamion-1,3,5-triazin-2-yl）amion]stilbene-2,2＇-disulphonate（VBL） obtained by pig skin migration FS and fiber paper migration FS were 0.03 and 0.05 mg/m2, respectively. 96 kinds of samples were analyzed and the migration amounts of FWAs in 21 kinds of samples were detectable. Correlations between migration amounts obtained by the three methods were very good. Experimental results indicate that the present methods can be applied to the determination of migration amount of FWAs in facial masks.
