Methylene Green iodide

Based on AA oxidation to dehydroascorbic acid in acidic medium using iodine-iodide solution as oxidizing reagent. The iodine amount consumed in the redox reaction was detected Electrocatalysis of AA on a glassy carbon electrode chemically modified with polyaniline films AA was determined at a vitreous C electrode modified with 3,4-dihydroxybenzaldehyde AA was determined with a chemically modified with methylene green (electron mediator) carbon paste electrode... 

Iodide ions (as F or I3 ) can be extracted as ion-pairs with basic dyes such as Crystal Violet [8,9], Brilliant Green [10,11], Rhodamine B (in toluene) [12], or Butylrhodamine (in benzene) [13]. After oxidation of iodide to iodine, the iodine is extracted into CCI4 and then stripped into the aqueous phase (as F) by shaking with thiosulphate. Finally, the F ions associated with Methylene Blue, are extracted into 1,2-dichloroethane [14]. 

In a sensitive flotation-spectrophotometric method (e = 3.4-10 ), a compound [(MB )(Hgl3)]-3[(MB )(l3)] (MB = Methylene Blue) is separated by flotation with cyclohexane from a 0.4 M HCl medium, containing T and MB then it is washed with water and dissolved in methanol [55]. Mercury has also been determined spectrophotometrically after separation (by flotation with cyclohexane) from solutions containing the iodide complex and Brilliant Green (e = 5.96-10 ) [56]. 

Sensitive extraction-spectrophotometric methods are based on the extractable (into CHCI3, 1,2-diehloroethane, benzene, or toluene) ion-associates of basic dyes and anionic Ag complexes with cyanide [35,36], iodide [37,38], and bromide [39]. In these methods, use has been made of such dyes as Crystal Violet [35,39], Brilliant Green [38,39], Malachite Green [39], Methylene Blue [36], and Nile Blue A [37]. In some of these methods the molar absorptivities are elose to MO [36,39]. A flotation method has been proposed, based on the addition compound [R6G ][Ag(SCN )2] [R6G ][SCN ] which is formed by silver ions (at pH 2-5) in the presence of thiocyanate and Rhodamine 6G (flotation with DIPE, the precipitated compound is washed and dissolved in acetone, e = 1.5-10 ) [40]. The complex Ag(CN)2 , associated with Crystal Violet, has been utilized in another flotation-spectrophotometric method of determining silver [41]. Silver has been determined also in a system comprising thiocyanate and Rhodamine B, as an aqueous pseudo-solution, in the presence of poly(vinyl alcohol) [42]. 

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