A Method for the Quantitative Microdetermination of Glucose and Maltose in Mixtures

Morris, Daniel L.

doi:10.1016/s0021-9258(18)71889-9

Cited by 2 publications

(1 citation statement)

References 8 publications

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“…Few recent papers on sugar analyses deal with small samples Interest appears to be centered in the accurate accounting of minute amounts of the sugars. These papers (159,181,193, 2S6, 261) include colorimetric methods for traces of glucose, methods for total sugars with the Suff-Scharol reagents, the Bertrand and Somogyi methods, and the Hawthorne paper chromatography method for separating and estimating (82) sugar.…”

Section: Sugarsmentioning

confidence: 99%

Organic Microchemistry

Willits¹

1949

Anal. Chem.

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MICROCHEMICALanalyses of organic compounds still follow largely the pattern set by Fritz Pregl. Considerable strides have been made during the past 6 years, as evidenced by the increase in the number of microchemical laboratories and the wider application of microanalytical chemical techniques. During the late twenties and early thirties, microanalytical methods were but little used in the United States except in the Atlantic Coast states. Ten years later these methods had been introduced into the midwestern states, and today micromethods are in use in analytical laboratories throughout the country.The keen interest shown in the development of microchemical analysis is exhibited by the establishment of a committee on the performance of microchemical balances (A. H. Corwin of Johns Hopkins University, chairman); a revival of the committee on standardization of microchemical apparatus (A. Steyermark, chairman); and the re-establishment of a referee on the standardization of microchemical methods by the Association of Official Agricultural Chemists. The British Standards Institute has formed a subcommittee to standardize microchemical apparatus, and the work of this subcommittee is well advanced. Microchemistry has gone a long way since Pregl devised this scheme of analysis, for it is no longer limited to the analysis of material available in only small amounts. Instead, it has an accepted place, along with micromethods, for the analysis of materials available in large amounts. The micromethod is superior, in that it is faster, more economical of reagents, and in many instances more precise and accurate.

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Section: Sugarsmentioning

confidence: 99%

Organic Microchemistry

Willits¹

1949

Anal. Chem.

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Starches and starch fractions. Part I. The determination of dextrose and maltose by the ferri‐cyanide‐carbonate reagent, with special reference to the effect of inorganic salts

Lampitt¹,

Fuller²,

Goldenberc³

et al. 1947

J. Chem. Technol. Biotechnol.

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L A M P I , Et A/.-STA RCHES A N D STARCH FRACTIONS. PARTI J.S.C.I., 66, March, rg17 111. Spec$city.-The reactions of the compounds listed in Table I1 are discussed individually below. op'DDT.-This gave no colour with the hydroquinonel sulphuric acid reagent in the cold but darkened slightly on heating. When treated esactly as described for the determination of D D T I mg. of op'DDT gave an average Spekker reading of 0.029 compared with 0-600 for pure DDT. pp'DDD.-This substance gave a very faint pink colour on heating at 100' for three minutes with the reagent. I mg. gave Spkker readings of 0.038 compared with 0.600 for pure DDT.pp'DDT olefitre.-One mg. of pp'DDT olefine gave a bright rose pink colour on standing at laboratory temperature. The co!our appeared slowly and was only fully developed after five mmutes. Heating to 1 0 0~ for three minutes intensified the colour. It was later discovered that hydroquinone was unnecessary for this colour reaction which goes quite readily when the olefine is treated with diethyl sulphate and sulphuric acid. Using this fact it might be possible to devise a method for the estimation of DDT olefine in the presence of DDT. A smooth calibration curve can be obtained by treating known amounts of D D T olefine with diethyl sulphate and sulphuric acid at IWO. pp'DDD olefine.-pp'DDD o l e h e gave an intense orange-red colour immediately when treated with the hydroquinonelsulphuric acid reagent at room temperature. The colour was fully developed at once but fading began after 10 minutes. Heating to 100' for three minutes intensified the colour. As with pp'DDT olefine the same colour was obtained in the absence of hydroquinone. Sensitivity tests showed that 0.01 mg. of pp'DDD olefine is just detectable by the colour it produces with the reagent at 3 0 ' .IV. Cottiparison with the crystallisation ttiethod.-Six commercial samples of DDT were analysed in quintuplicate for pp'DDT content by both the Cristol and Hayes method' and the hydroquinonelsulphuric acid method. In the determination by crystallisation the technique described by Cristol and Hayes was followed exactly with the exception of the use of a thermostat, which was nor available. Temperatures during the crystallisation were maintained at 25 f 2 O . Information concerning the source of manufacture, batch number etc. of the commercial samples used was not available except in .the case those labelled D and F in Table V, which were of Monsanto and Du Pont manufacture respectively. Discussion of resultsThat the technique of this colorimetric method is accurately reproducible is shown by the determinations of known amounts of purepp'DDT (Table VI) where the standard deviation between found and known results was only 0.5%.The applicability of the method to the analysis of commercial samples is claimed on the results of analyses of mixtures of known composition of pp'DDT with op'DDT and pp'DDD (the major impurities of technical DDT) and the non-interference of other impurities in the concentrations at which they are found in th...

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A Method for the Quantitative Microdetermination of Glucose and Maltose in Mixtures

Cited by 2 publications

References 8 publications

Organic Microchemistry

Organic Microchemistry

Starches and starch fractions. Part I. The determination of dextrose and maltose by the ferri‐cyanide‐carbonate reagent, with special reference to the effect of inorganic salts

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