Based on the inhibition by hydroquinone, catechol and resorcinol of chemiluminescence from luminol potassium hexacyanoferrate(Ⅲ) system, a high performance liquid chromatographic procedure with chemiluminescent detec...Based on the inhibition by hydroquinone, catechol and resorcinol of chemiluminescence from luminol potassium hexacyanoferrate(Ⅲ) system, a high performance liquid chromatographic procedure with chemiluminescent detection was developed for simultaneous determination of hydroquinone, catechol and resorcinol. The separation was carried out on RP C 18 column at 37 ℃ by using a step gradient elution made by the mobile phases of methanol(A) and 0 05% H 3PO 4(B). The gradient elution condition was 95% B, 5 min; 95%B 50%B, 1 min; 50% B, 6 min. This method has the merits of high senstivity and good selectivity. The detection limits for hydroquinone, catechol and resorcinol are 2 0×10 -9 , 3 2×10 -9 and 6 8×10 -7 g/mL, respectively. The relative standard deviation( n =5) is 1 9% for 2 5×10 -7 g/mL hydroquinone, 1 0% for 7 5×10 -7 g/mL catechol, 4 0% for 5 0×10 -5 g/mL resorcinol, respectively. The recovery is in the range of 94%—104%. [WT5HZ]展开更多
Solid state reaction between La (Ac)3·3/2H2O and 8-hydroxyquinoline (Oxine)was studied at a low heating temperature. La (Oxine)3 was synthesized by one step solid state reaction at 60℃, and the product is charac...Solid state reaction between La (Ac)3·3/2H2O and 8-hydroxyquinoline (Oxine)was studied at a low heating temperature. La (Oxine)3 was synthesized by one step solid state reaction at 60℃, and the product is characterized by elementary analysis, IR, XRD,photoacoustic spectra and flourenscence spectra. The influence of the temperature on solid state reaction was discussed.展开更多
Electrochemical oxidation reactions of L ascorbic acid(AA) at a copper cobalt hexacyanoferrate modified electrode(CoCuHCF/Pt) in neutral solutions were studied in comparison with that at a bared Pt electrode by in sit...Electrochemical oxidation reactions of L ascorbic acid(AA) at a copper cobalt hexacyanoferrate modified electrode(CoCuHCF/Pt) in neutral solutions were studied in comparison with that at a bared Pt electrode by in situ FTIR reflection absorption spectroscopy(FTIRRAS). The results indicated that the electrode oxidation of AA at both the electrodes CoCuHCF followed by chemical processes. AA is oxidized to dehydro L ascorbic acid(DHA) followed by a chemical hydration process. At Pt electrode, the DHA underwent hydration reaction to form bicyclic product, which then further was transformed into 2,3 diketogulonic acid and its enol form via an opening of lactone ring. However, at CoCuHCF/Pt electrode, the DHA undergoes ring opening reaction and then degradation reaction.展开更多
文摘Based on the inhibition by hydroquinone, catechol and resorcinol of chemiluminescence from luminol potassium hexacyanoferrate(Ⅲ) system, a high performance liquid chromatographic procedure with chemiluminescent detection was developed for simultaneous determination of hydroquinone, catechol and resorcinol. The separation was carried out on RP C 18 column at 37 ℃ by using a step gradient elution made by the mobile phases of methanol(A) and 0 05% H 3PO 4(B). The gradient elution condition was 95% B, 5 min; 95%B 50%B, 1 min; 50% B, 6 min. This method has the merits of high senstivity and good selectivity. The detection limits for hydroquinone, catechol and resorcinol are 2 0×10 -9 , 3 2×10 -9 and 6 8×10 -7 g/mL, respectively. The relative standard deviation( n =5) is 1 9% for 2 5×10 -7 g/mL hydroquinone, 1 0% for 7 5×10 -7 g/mL catechol, 4 0% for 5 0×10 -5 g/mL resorcinol, respectively. The recovery is in the range of 94%—104%. [WT5HZ]
文摘Solid state reaction between La (Ac)3·3/2H2O and 8-hydroxyquinoline (Oxine)was studied at a low heating temperature. La (Oxine)3 was synthesized by one step solid state reaction at 60℃, and the product is characterized by elementary analysis, IR, XRD,photoacoustic spectra and flourenscence spectra. The influence of the temperature on solid state reaction was discussed.
文摘Electrochemical oxidation reactions of L ascorbic acid(AA) at a copper cobalt hexacyanoferrate modified electrode(CoCuHCF/Pt) in neutral solutions were studied in comparison with that at a bared Pt electrode by in situ FTIR reflection absorption spectroscopy(FTIRRAS). The results indicated that the electrode oxidation of AA at both the electrodes CoCuHCF followed by chemical processes. AA is oxidized to dehydro L ascorbic acid(DHA) followed by a chemical hydration process. At Pt electrode, the DHA underwent hydration reaction to form bicyclic product, which then further was transformed into 2,3 diketogulonic acid and its enol form via an opening of lactone ring. However, at CoCuHCF/Pt electrode, the DHA undergoes ring opening reaction and then degradation reaction.
