Determination of Lithium in Rocks by Distillation

Fletcher, Mary

doi:10.1021/ac60025a031

Cited by 8 publications

(4 citation statements)

References 31 publications

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“…When 95% 1 Present address, University of Maryland, College Park, Md. 2 Present address, U. S. Geological Survey, Washington, D. C. out by the wet method or by the distillation procedure. Sodium and potassium are removed by alcohol and ether, but complete separation is not necessary.…”

Section: Reagents and Apparatusmentioning

confidence: 99%

Determination of Lithium in Rocks

White¹,

Fletcher²,

Parks³

1951

Anal. Chem.

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The gravimetric method in general use for the determination of lithium is tedious, and the final weighed product often contains other alkali metals. A fluorometric method was developed to shorten the time required for the analysis and to assure that the final determination is for lithium alone. This procedure is based on the complex formed between lithium and 8-hydroxyquinoline. The fluorescence is developed in a slightly alkaline solution of 95% alcohol and measurement is made on a photoelectric fluorometer. Separation from the ore is carried HE difficulties inherent in the gravimetric determination of T lithium in minerals have been reviewed by Kallmann (6) and by Fletcher ( 2 ) . In nearly all methods previously reported for this determination, partial separations from t,he other alkalies are made and a correction factor is used t'o compensate for the sodium and potassium remaining with the lithium; or very careful separations are made and the final residue is weighed as a pure lithium salt. However, even after a supposedly "complete separation," as in the sulfate gravimetric method, the final lithium sulfate residue contains traces of calcium and magnesium as well as some sodium and potassium. Seedless to say, it would be far better to be able to determine the lithium directly instead of having to depend on the complete separation of all other ions.In an effort to develop a direct method for the determination of lithium, a group of compounds was studied with the hope of finding a specific colorimetric or fluorometric reagent. Inasmuch as lithium has been frequently described as an interference in reactions involving beryllium, attention was directed to those compounds (chiefly the hydrosyanthraquinones) that had been reported (8) to give either direct color or fluorescence responses with beryllium. None of these compounds was found sensitive enough to serve for quantitative purposes; but oxine (&hydroxyquinoline) formed an intensely fluorescing chelate complex wit.h lithium and appeared to be the best reagent available.Oxine will give a quantitative response wit'h as little as 5 micrograms of lithium oxide in 25 nil. of solution and does not form a fluorescent substance with either sodium or potassium. Lithium may be determined with this reagent to an accuracy of 1 part in lo00 in solutions that contain no other cations. Appreciable quantities of sodium decrease the intensity of the fluorescence of the lithium-oxine complex; therefore, a partial separation of the sodium is necessary. The advantages of using the oxine reaction for the determination of lithium are that a direct quantitative determination may be made without a complete separation of the other alkalies or the use of correction factors; and at the same time, greater accuracy is achieved in shorter time than is possible with the sulfate gravimetric determination. REAGENTS AND APPARATUSAlcohol. Redistilled 95% ethyl alcohol wr.as used for the preparation of all solutions in the fluorometric procedure. Commercial alcohol contains a highly fluorescent...

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Section: Reagents and Apparatusmentioning

confidence: 99%

Determination of Lithium in Rocks

White¹,

Fletcher²,

Parks³

1951

Anal. Chem.

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“…The results of several distillation programs were reported. Among these are the analysis of recycle styrene (Glasgow et al,50), the determination of polymer in furfural (Hillyer and Deutschman, 63), and the determination of lithium in rocks by distillation of lithium chloride from the sintered sample (Fletcher,43). All three techniques are suitable for quantitative analytical work.…”

Section: Laboratory Distillationsmentioning

confidence: 99%

“…Swallow and Gourla)' (56) surveyed vacuum evaporation for the metalization of surfaces and the purification of high polymers and natural oils from low molecular weight contaminants. Morse (43) described American equipment in the megavacuum range for orange juice and biologicals, and Stauffer1 (S3), also from National Research Corporation, described the reduction and distillation of magnesium and calcium. A paper of some interest for this review' was Fawcett's appraisal of molecular distillation (22).…”

Section: Inmentioning

confidence: 99%

High Temperature Distillation.

Walsh¹

1950

Ind. Eng. Chem.

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“…The qualitative and quantitative determination of lithium has presented one of the more difficult problems in analytical chemistry, due mainly to the similarities of lithium to other alkali metals and alkaline earths. Over the years, early analytical techniques for measuring lithium have included gravimetric (14), fluorometric (15), colorimetric (16)(17)(18) and separation techniques (19).…”

Section: Introductionmentioning

confidence: 99%

Spectrophotometric Measurement of Lithium in Human Saliva Using the Chromogenic Reagent Thorin

PhD

2023

Preprint

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This study explored the feasibility of using the chromogenic dye Thorin to spectrophotometrically measure the lithium concentration in human saliva. The absorbance wavelength maximum of the Li-Thorin complex was determined to be 480 nm. Lithium concentrations were measured spectrophotometrically at 480 nm in human pooled saliva with lithium added to produce calibration standards of 0.00-5.29 mEq/L of lithium, which corresponds to a blood lithium range of 0.00-2.60 mEq/L, assuming a saliva/blood ratio of 2/1. A least-squares fit of the absorbance vs lithium concentration calibration data produced a regression equation y = 0.128x + 1.449 with correlation coefficient = 0.997. This regression equation was then used to predict lithium concentrations from absorbance data in prepared lithium/saliva test solutions and in hospitalized patients being treated with lithium. The results generally agreed well with those determined by atomic absorption spectroscopy. By measuring absorbance of test saliva vs reagent blank containing the same amount of saliva, interfering effects of saliva protein and electrolytes in the test samples were avoided. This study supports the continued exploration of this method as a non-invasive point-of-care testing approach for monitoring saliva lithium during lithium treatment.

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Determination of Lithium in Rocks by Distillation

Cited by 8 publications

References 31 publications

Determination of Lithium in Rocks

Determination of Lithium in Rocks

High Temperature Distillation.

Spectrophotometric Measurement of Lithium in Human Saliva Using the Chromogenic Reagent Thorin

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