Ascorbate solution

Pfister, R. R., Patterson, C.A. and Hayes, S.A. (1982). Effect of topical 10% ascorbate solution on established comeal ulcers after severe alkali bums. Invest. Ophthalmol. Vis. Sd. 22, 382-387. 

With rapid mixing of the chloroauric acid/carbonate solution, quickly add 1ml of a 7 percent sodium ascorbate solution prepared in water. Maintain the solution cooling in an ice bath. Higher temperatures will create larger particle sizes. The color of the solution at this point will turn to a purple-red. 

Transition-metal-ion-free solutions of ascorbate autoxidize (i.e., react with 02) only slowly (e.g., carefully demetalized with a chelating resin such as Chelex 100 1.25 x 10-4mol dm"3 solutions lose only 0.05% ascorbate/15min (Buettner 1988 for a review giving valuable information how to deal with ascorbate solutions, see Buettner and Jurkiewicz 1995). The stability of ascorbate solutions is dramatically reduced in the presence of EDTA which apparently catalyzes the degradation by chelating adventitious iron ions (Buettner and Jurkiewicz 1995). 

Ascorbic acid or sodium ascorbate—Solutions are prepared by the students just before use (see Experiment 14). Approximately 25 g will be required. 

Studies (20) of the radical in oxygenated neutral or alkaline ascorbate solutions (pH 6.6-9.6) showed that the spectrum could be resolved into a doublet of triplets (1.7 and 0.17 G) with an intensity ratio close to 1 2 1. 

This can be seen in Figure 9.12, where square-wave voltammetries (SQWVs) at monoclinic ("Co io/roydOj-rnodificd electrode immersed into MDA plus dopamine and MDA plus ascorbate solutions in aqueous phosphate buffer are depicted. Here, the MDA-localized oxidation peak at +1.0 V vs. AgCl/Ag is clearly separated from peaks corresponding to the oxidation of dopamine and ascorbate at ca. +0.20 V. Remarkably, the sensitivity for MDA is greater than those for its possible interferents, dopamine and ascorbate. 

The plants in three of the plots were sprayed with 10 1/plot of a titanium-ascorbate solution (Titavit, 10 mg/1). In other three plots the plants were sprayed with 10 1/plot of a kalium-ascorbate solution (with the same ascorbate concentration as in the Titavit solution). The remaining three plots were used as a control and were spray with water. A group of ten plants from every plot received a second shock-treatment, with the same solutions and concentrations, two weeks before sampling. 

Using a 10 M ascorbate solution under the same experimental... 

High volume (4L) of PEG and low palatability makes this solution poorly tolerated. Fonchon and colleagues conducted a study to compare the efficacy, safety and acceptability of a 2L PEG+ascorbate solution with the standard 4L PEG solution [52 J. Adults referred for colonoscopy were randomised to receive 2L PEG+ascorbate (n=202) or 4L PEG (n= 198) solution. Colon cleansing success was assessed, and safety and acceptability were measured. 

Fonchon T, Boustiere C, Hersbach D, Tarrerias AL, Halphen M. A low-volume polyethylene glycol plus ascorbate solution for bowel cleansing prior to colonoscopy The NORMO randomized clinical trial. Dig Liver Dis 2013 45(10) 820-6. 

Use of ascorbate solution as both an eluent and a reducing agent following by molybdate derivatization... 

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