In a thin HCl medium,RRS intensities of an alone CS or acidic triphenylmethane dye (TPMD) are very week. However,when TPMD reacts with a CS to form an ion-associate,the RRS intensity is enhanced greatly and a new RRS ...In a thin HCl medium,RRS intensities of an alone CS or acidic triphenylmethane dye (TPMD) are very week. However,when TPMD reacts with a CS to form an ion-associate,the RRS intensity is enhanced greatly and a new RRS spectrum appears. The spectral characteristics of the RRS for the ion-associates and the optimum conditions for the reactions are investigated. The intensity of RRS is directly proportional to the mass concentration of CS in the range of 0—3.5 or 0—5.0 μg/mL. The method has a high sensitivity for the determination of CS,their detection limits are between 3.1 and 9.8 ng/mL depending on the different CS. In this case,most metal and non-metal ions do not interfere,so that the method has a good selectivity. Therefore,a sensitive,selective,simple and rapid method for the determination of CS by RRS is developed. [WT5HZ]展开更多
A new spectrophotometric method for the determination of trace heparin has been studied. The method was based on the discoloration reaction between heparin and bisphenylnaphthylmethane dyes such as victoria blue 4R(VB...A new spectrophotometric method for the determination of trace heparin has been studied. The method was based on the discoloration reaction between heparin and bisphenylnaphthylmethane dyes such as victoria blue 4R(VB4R), victoria blue B(VBB) and night blue(NB) in weak acid medium. The reduction in absorbance was directly proportional to the concentration of heparin. The linear ranges of heparin were from 0 to 2.4 μg/mL for all systems. The molar absorptivities( ε ) of the three systems were between 2.11×10 6 and 2.66×10 6 L·mol -1 ·cm -1 and the sensitivity of VB4R system was the highest. Taking VB4R system for an example, the effects of some coexisting substances on the determination of heparin have been investigated and the results showed that the method had a good selectivity. The method has been applied to determination of the heparin samples with satisfactory results.展开更多
There are an absorption peak at 485 nm and a synchronous fluorescence peak at 510 nm for fluorescein in the medium of 3.4×10 -3 mol/L tri-sodium citrate. The gold nanoparticle system exhibits a characterization r...There are an absorption peak at 485 nm and a synchronous fluorescence peak at 510 nm for fluorescein in the medium of 3.4×10 -3 mol/L tri-sodium citrate. The gold nanoparticle system exhibits a characterization resonance scattering peak at 580 nm. In the coexisting system of gold nanoparticle and fluorescein, there are a synchronous fluorescence peak at 510 nm and a resonance scattering peak at 580 nm. It has been found that the fluorescence peak may be quenched by gold nanoparticle. When the concentration of fluorescein is higher, the A 470 nm affects the I 470 nm of gold nanoparticle. The I 470 nm decreases exponentially with the concentration of fluorescein.展开更多
文摘In a thin HCl medium,RRS intensities of an alone CS or acidic triphenylmethane dye (TPMD) are very week. However,when TPMD reacts with a CS to form an ion-associate,the RRS intensity is enhanced greatly and a new RRS spectrum appears. The spectral characteristics of the RRS for the ion-associates and the optimum conditions for the reactions are investigated. The intensity of RRS is directly proportional to the mass concentration of CS in the range of 0—3.5 or 0—5.0 μg/mL. The method has a high sensitivity for the determination of CS,their detection limits are between 3.1 and 9.8 ng/mL depending on the different CS. In this case,most metal and non-metal ions do not interfere,so that the method has a good selectivity. Therefore,a sensitive,selective,simple and rapid method for the determination of CS by RRS is developed. [WT5HZ]
文摘A new spectrophotometric method for the determination of trace heparin has been studied. The method was based on the discoloration reaction between heparin and bisphenylnaphthylmethane dyes such as victoria blue 4R(VB4R), victoria blue B(VBB) and night blue(NB) in weak acid medium. The reduction in absorbance was directly proportional to the concentration of heparin. The linear ranges of heparin were from 0 to 2.4 μg/mL for all systems. The molar absorptivities( ε ) of the three systems were between 2.11×10 6 and 2.66×10 6 L·mol -1 ·cm -1 and the sensitivity of VB4R system was the highest. Taking VB4R system for an example, the effects of some coexisting substances on the determination of heparin have been investigated and the results showed that the method had a good selectivity. The method has been applied to determination of the heparin samples with satisfactory results.
文摘There are an absorption peak at 485 nm and a synchronous fluorescence peak at 510 nm for fluorescein in the medium of 3.4×10 -3 mol/L tri-sodium citrate. The gold nanoparticle system exhibits a characterization resonance scattering peak at 580 nm. In the coexisting system of gold nanoparticle and fluorescein, there are a synchronous fluorescence peak at 510 nm and a resonance scattering peak at 580 nm. It has been found that the fluorescence peak may be quenched by gold nanoparticle. When the concentration of fluorescein is higher, the A 470 nm affects the I 470 nm of gold nanoparticle. The I 470 nm decreases exponentially with the concentration of fluorescein.
