Ferricyanide method

Glucose. There are four basic principles utilized for glucose analysis. The most widely used depends upon the reduction of some element such as copper or iron. This is the principle of the Folin-Wu method, the ferricyanide method, used on the Autoanalyzer, and the cupreine ( ) method used on the SMA-12/60. 

A new development is that electrochemical oxidation of ferrocyanide to ferricyanide can be coupled with AD to give a very efficient electrocatalytic process [37]. Under these conditions, the amount of potassium ferricyanide needed for the reaction becomes catalytic and Eqs. 6D.6 and 7 can be added following Eq. 6D.4. Summation of Eq. 6D.1-6D.4, 6D.6, and 6D.7 gives 6D.8, showing that only water in addition to electricity is needed for the conversion of olefins to asymmetric diols and that hydrogen gas, released at the cathode, is the only byproduct of this process. In practice, sodium ferrocyanide is used in the reaction and the amount of this reagent used in comparison with the potassium ferricyanide method mentioned above has been reduced from 3.0 equiv. to 0.15 equiv. (relative to an equivalent of olefin). 

The oxidation of iV-methylphenanthridinium hydroxide to N-methylphenanthridone by benzoquinone appears mechanistically similar to the older ferricyanide method. Use of the quinone is reported to offer no preparative advantage.358... 

After correction for dilution, the ferricyanide method yields 18 3 pg/mL. This concentration of carbohydrate will produce a signal in the DABA assay that is equivalent to 33 pg/mL of DNA (18 x 330/180). The remaining signal in the DABA assay is due to DNA its concentration is therefore 11 pg/mL. A dyebinding assay (e.g., ethidium bromide) can be used as a confirmative method. 

Each value is the average of duplicate analysis. Endogenous glucose was determined to be 860 jg/ml by an automated ferricyanide method. 

Several methods can be used for the determination of chloride in water [2], The argentometric and mercuric nitrate methods are based on the titration of chlorine in the presence of an indicator. Experimental procedures are easy, but many substances may interfere with the results. There are also other methods such as potentiometry, capillary electrophoresis and other automated methods (ferricyanide method or flow injection analysis). 

Analytical estimation of Cl in soil suspensions can be performed (following filtration or centrifugation) by potentiometric titration, automatic colorimetric analysis (automated ferricyanide method) and ion chromatography. Choice of... 

Although ferricyanide method to produce DNPOH has many advantages, a large amount of oxidants is used in this process, and a large amounts of waste is produced, in which contains a large amount of salt and pollution on environment, and the treatment costs is increased. 

Chemical methods Classical methods Ferricyanide method lodometry method... 

The reasons for allowing such high glucose values to persist requires explanation. The blood sugar values were estimated in the routine laboratory on microsamples using the automated ferricyanide method. Unless specimens are diluted, this method becomes inaccurate at sugar values above 250 mg per 100 ml. Specimens giving this result were reported as such and not repeated on diluted samples. Also,... 

A number of important methods are based on the oxidation of sugars by ferricyanide ion in alkaline solution. The method is open to the same objections as the copper reduction methods, namely, the lack of a stoichiometric reaction and the dependence of the method on arbitrarily chosen conditions. The ferricyanide may be used to titrate the sugar solution directly by the use of picric acid or of methylene blue as an indicator. Or, the reduced ferrocyanide may be precipitated as the zinc salt, and the excess ferricyanide determined iodometrically. The Hagedom-Jensen method and the Hanes modification utilize the latter procedure. In the Folin-Malmros micro method, Prussian blue is formed and determined colorimetrically. Extensive application of the ferricyanide method has been made in the determination of the diastatic power of amylase preparations and in blood analysis. 

It is difficult to correlate reducing sugar units based on different analytical methods. Hahn (63) determined the reducing values for enzymic digests of hyaluronic acid by the Somogyi, the Hagedorn-Jensen, and the hypoiodite methods (108). The results obtained with the copper sulfate and hypoiodite methods were 60 and 36% lower, respectively, than those obtained with the ferricyanide method. 

Consequently these authors adapted their ferricyanide method to the... 

The following official cationic surface-active agents are assayed by the ferricyanide method given under Flavines, p. 255, with the minor modifications of using 3 to 3-5 g and keeping the solutions cool during the precipitation and subsequent titration ... 

According to this equation, the LOQs were found to be 0.217, 0.347 and 0.76 pg mL-1 for the Fe2+-phen, Fe2+-bipyridyl and Fe2+-ferricyanide methods, respectively. 

---