A novel ternary system for the determination of ascorbic acid concentration based on resonance Rayleigh scattering

2015 ◽  
Vol 7 (23) ◽  
pp. 9963-9970 ◽  
Author(s):  
Qin Li ◽  
Zhan Zhang ◽  
Wenyan Yao ◽  
Jin Li ◽  
Jidong Yang

The dienol of ascorbic acid was observed to have a strong reducing power in a 1.44 M HCl buffer solution, and could reduce Fe3+ to Fe2+.

1971 ◽  
Vol 26 (02) ◽  
pp. 275-288 ◽  
Author(s):  
S Chattopadhyay ◽  
D. D Johnson ◽  
G. J Millar ◽  
L. B Jaques

SummaryRats were subjected to the following procedures: No treatment, Stressor (10% NaCl i.p.), Warfarin for 7 days, Stressor followed by Warfarin; and groups were sacrificed at intervals for assessment of spontaneous hemorrhage and of adrenal ascorbic acid concentration. There was no hemorrhage in the no treatment and stressor groups; some hemorrhage in the warfarin group; profound hemorrhage with Warfarin + Stressor. The adrenal ascorbic acid concentration was found to be lower, 8 h and again 5 days after stress, and remained lower in the warfarin + stress animals. Warfarin had no effect on adrenal ascorbic acid level.In another series of experiments in which the stress consisted of an electric current to the cage floor for 6 sec over 15 min, rats were sacrificed daily for determination of serum corticosterone concentration and occurrence of spontaneous hemorrhage. There was a statistically significant increase of serum corticosterone concentration with stress, warfarin and combined warfarin and stress treatments (P< 0.001 for all three variables). There was a significant correlation (r = 0.96 and 0.89, P< 0.01) for serum corticosterone concentration with hemorrhage score and incidence of hemorrhage in stressed rats receiving warfarin, but not in those receiving only warfarin. The results indicate an activation, rather than an exhaustion, of the pituitary-adrenal axis during the combined action of anticoagulant and stress, which results in the development of spontaneous hemorrhage.


2013 ◽  
Vol 787 ◽  
pp. 400-403
Author(s):  
Jin Chao Dong ◽  
Ai Hui Liang ◽  
Zhi Liang Jiang

Hemin aptamer was used to modify gold nanoparticles (AuNPs) to obtain a stable aptamer-nanogold probe (AussDNA). In the condition of pH 8.0 Tris-HCl buffer solution containing 50mmol/L NaCl, the substrate chain of AussDNA was cracked by hemin to produce a short single-stranded DNA(ssDNA) and then further combined with hemin to form a stable hemin-ssDNA conjugate. The AuNPs released from AussDNA would be aggregated in the condition of 50mmol/L NaCl and exhibited a strong resonance Rayleigh scattering (RRS) peak at 368nm. Under the selected conditions, the increased RRS intensity (ΔI368nm) was linear to hemin concentration in the range of 5-750nmol/L, with a detection limit of 66 pmol/L. This RRS method was applied to determination of residual hemin in serum samples, with satisfactory results. The remnant AussDNA in the solution exhibited a strong catalytic activity on the gold particle reaction of HAuCl4-vitamine C (VC) that can be monitored by RRS technique at 368 nm. When the hemin concentration increased, the AussDNA decreased, the catalysis decreased, and the RRS intensity at 368nm decreased. The decreased RRS intensity ΔI368nmwas linear to the hemin concentration in the range of 1-200nmol/L, with a detection limit of 54 pmol/L. Accordingly, a sensitivity, selectivity, and simplicity new method of resonance Rayleigh scattering spectra to detect hemin using aptamer-modified nanogold as catalyst was established.


2017 ◽  
Vol 3 (1) ◽  
pp. 19-22
Author(s):  
Fabian Audu Ugbe ◽  
Victoria Abiola Ikudayisi ◽  
Oluwagbemiga Tayo Amusan

This research was aimed at investigating the concentration of Ascorbic Acid (Vitamin C) in some commercial fruits juices: ‘5’ Alive, Hollandia yoghurt, Nutri milk, Ribena, Lacasera, Happy hour, Viju milk, Chi exotic and Chi vita sold in Ugbokolo, Benue State, Nigeria by titrimetric method using 2,6-dichlorophenolindophenol (DCPIP) as titrant. The ascorbic acid (AA) content in milligram per 100ml of the various juices investigated is in the order: ‘5’ Alive (11.25) > Ribena (5.47) > nutri milk (5.31) > Happy hour (4.38) > Hollandia yoghurt (1.25) > Lacasera (0.47) ≈ Chi exotic (0.47) >Viju milk (0.31) > Chi vita (0.16). It was observed that half a litre of ‘5’ Alive (56.25 mg AA) a day is suitable for adults and pregnant women, a liter each of Ribena  (54.70 mg AA) and Nutri milk (53.10 mg AA) per day for adults, while a litre of Happy hour (43.80 mg AA) per day is suitable for adolescents. It can be concluded that commercial fruits juices when taken in large amount will add to the daily human dietary intake of the vitamin.


2013 ◽  
Vol 664 ◽  
pp. 749-753
Author(s):  
Li Li Xu ◽  
Zhi Liang Jiang ◽  
Ai Hui Liang

Using PEG-10000 and sodium citrate as stabilizer, and NaBH4 as reducer, a stable nanosilvers (AgNPs) sol was prepared. In pH 6.6 phosphate buffer solution containing NaCl, the AgNPs were aggregated to large particles, which lead to resonance Rayleigh scattering (RRS) peak at 350 nm enhancement. Upon addition of cysteine, the peak decreased. The decreased value ΔI is linear to cysteine concentration in the range of 5-60×10-8 mol/L. Thus, a new RRS method was proposed for detection of cysteine.


2013 ◽  
Vol 680 ◽  
pp. 141-144 ◽  
Author(s):  
Qing Ye Liu ◽  
Gui Qing Wen ◽  
Kun Li ◽  
Ai Hui Liang

In pH 6.6 Na2HPO4- citric acid buffer solution and in the presence of KCl, the immunoreaction between hCG and nanosilver-labeled anti-hCG took place, the immunonanosilver-complex was formed and deposited, caused the resonance Rayleigh scattering (RRS) intensity at 510 nm decreased. In the optimal condition, the decreased RRS intensity responds linearly with the concentration of hCG over 0.125-1.75 µg/mL. Based on this, a new and simple RRS method has been proposed for the determination of hCG in serum samples, with satisfactory results.


2013 ◽  
Vol 830 ◽  
pp. 448-451
Author(s):  
Ling Ling Ye ◽  
Ai Hui Liang

In pH 4.2 HAc-NaAc buffer solution, hydroxylamine hydrochloride reduced Cu2+ to Cu+ that coordinate the nitrogen atom of 1,2,3-benzotriazole (BTA) to form Cu-BTA complex particles with a resonance Rayleigh scattering (RRS) peak at 369 nm. Under the selected conditions, when the BTA concentration increased, the RRS intensity at 369 nm increased. The increased RRS intensity ΔI369nm was linear to BTA concentration in the range of 0.17-13.36 µg/mL, with a regression equation of ΔI369nm = 89.91C + 96.7, and the detection limit is 0.17 µg/mL. Accordingly, a new RRS method for BTA was established.


2013 ◽  
Vol 299 ◽  
pp. 221-224
Author(s):  
Li Li Xu ◽  
Zhi Liang Jiang ◽  
Yu Zhen Wang ◽  
Hong Yang ◽  
An Ping Deng

Nanogold (NG) in size of 10 nm was prepared by the NaBH4 procedure. A new ligand 6-mercaptonicotinic acid (MNA) was used to couple both methylmercury chloride (CH3HgCl) and carrier protein to obtain an immunogen, it was immunized BALB/C mice, and the spleen cells of immunized mice were fused with myeloma cells. The monoclonal antibody (mAb) against mercury (II) ions was produced by the hybridoma technique. The mAb was labeled the NG to prepare an immunonanogold (ING) probe for Hg(II). In pH 5.4 Na2HPO4-citric acid buffer solution and under the condition of ultrasonic irradiation, the ING particles were aggregated un-specifically to form big particles that exhibited a strong resonance Rayleigh scattering (RRS) peak at 580 nm. When the Hg(II) was added, the specific immunoreaction of ING-Hg(II) take place, and the ING-Hg(II) immunocomplex dispersed in the solution that caused the RRS intensity decreasing linearly at 580 nm. The decreased intensity was linear to Hg(II) concentration in the range of 0.025-10 μmol/L, with a detection limit of 1.1 nmol/L Hg(II).


2013 ◽  
Vol 788 ◽  
pp. 19-22
Author(s):  
Xiao Jing Liang ◽  
Ai Hui Liang

Nanogolds (AuNPs) were synthesized with the citrate reduction of HAuCl4. In pH 3.0 glycineHCl buffer solution (0.20 mol/L), AuNPs do not aggregate. In the presence of Cr (III), that Cr (III) could form astable Cr (III) citrate complex with the citrate on surface of AuNP in 1: 2 binding stoichiometry, and the AuNPs were aggregated to big AuNPs clusters that led to the resonance Rayleigh scattering (RRS) peak at 530 nm increased greatly. Under the selected conditions, the increased RRS intensity (ΔI530nm) is linear to Cr (III) concentration in the range of 0.25-5.0 μmol/L. This RRS method was applied to determination of Cr (III) in synthetic samples, with satisfactory results. Cr (VI) was also detected after reduction to Cr (III).


2013 ◽  
Vol 664 ◽  
pp. 741-745
Author(s):  
Xin Hui Zhang ◽  
Yan Yan Wei ◽  
Chi Zhang ◽  
Miao Miao Chi ◽  
Jian Zhang ◽  
...  

Using PEG-10000 and sodium citrate as stabilizer, and NaBH4 as reducer, a stable nanosilver (AgNPs) sol was prepared. In pH 6.6 phosphate buffer solution containing NaCl, the AgNPs were aggregated to large particles, which lead to resonance Rayleigh scattering (RRS) peak at 350 nm enhancement. Upon addition of cysteine, the peak decreased. The decreased value ΔI is linear to cysteine concentration in the range of 5.0×10-8-6.0×10-7 mol/L. Thus, a new RRS method was proposed for detection of cysteine.


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