A New Moisture Tube

Alexander, Hendra

doi:10.1021/ac50102a042

Cited by 9 publications

(1 citation statement)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Therefore the loss in weight of the entire system is taken to represent the total volatile content of the powder which for a solventless powder may be taken to be the moisture content. 1 Present address, Chemistry Department, Columbia University, New York 27, N. Y.…”

mentioning

confidence: 99%

Estimation of Moisture in Solventless Double-Base Powders

Hardy¹,

Bonner²,

Noyes³

1946

Ind. Eng. Chem. Anal. Ed.

View full text Add to dashboard Cite

Desiccation, cone-and-dish, carbon tetrachloride distillation, and Karl Fischer procedures for the estimation of moisture in ballistitetype powders have been compared. Desiccation over concentrated sulfuric acid has been found satisfactory with respect to accuracy and also the simplest and most reproducible of these procedures, but under certain conditions the other methods are feasible for more rapid determinations.MOST solventless double-base powder manufactured at the present time is a mixture of nitrocellulose and nitroglycerin to which a few per cent of stabilizers, plasticizers, and inorganic salts have been added. Powders of this type are not notably hygroscopic, but finished samples in equilibrium with t heir surroundings contain a few tenths of a per cent of moisture. Precise control of the concentration of this constituent is essential to ensure satisfactory behavior of the finished powder. Several procedures for the estimation of moisture in smokeless powders have been reported (2, 3, 4), many of which are tedious and involved or are not capable of the necessary accuracy. The authors have selected the four procedures that appear most promising and have compared them carefully with regard to accuracy, reproducibility, and ease of operation, using several samples of ballistite-type powder containing approximately 0.2% moisture. The results of these comparisons are presented below, together with specific recommendations based upon them.EXPERIMENTAL PROCEDURES Desiccation Procedure. The desiccation procedure for the estimation of moisture involves storing the powder sample in a desiccator until the W'eight is constant; the moisture content is calculated from the total loss in weight of the sample.

show abstract

mentioning

confidence: 99%

Estimation of Moisture in Solventless Double-Base Powders

Hardy¹,

Bonner²,

Noyes³

1946

Ind. Eng. Chem. Anal. Ed.

View full text Add to dashboard Cite

show abstract

Determination of Moisture in Cereals: Review of Methods in Common Use

Bennett

Hudson

1954

Journal of the Institute of Brewing

View full text Add to dashboard Cite

Physical methods for moisture determination include oven drying at a specified temperature, with or without application of reduced pressure and use of desiccants, and direct reading after distillation with an immiscible solvent; methods depending on electrical conductivity or capacitance are limited in their accuracy by that of the reference method used for standardization. Of chemical methods, modifications of the Karl Fischer technique (using iodine, sulphur dioxide, pyridine and methanol) have found greatest acceptance. A survey of all these methods indicates that, whilst each may give results consistent with itself, the results of different methods do not necessarily agree. Accordingly, the need is indicated for further fundamental investigation of the nature of the problems involved in moisture assessment.

show abstract

Entrainment distillation as a reference method for the determination of the water content of foods: II. Development of a convenient method of entrainment distillation

Mossel

Reith

1951

Recl. Trav. Chim. Pays‐Bas

View full text Add to dashboard Cite

The procedure finally adopted is the following.Entrainer: Pure isooctane (2.2.4-trimethylpentane), bpt. 99" C. Apparatus: Still of 8 cm diameter, capacity about 150 ml; heating by means of an oil bath kept at about 165" C.Receiver of the Bidwell-Sterling-type; capacity of calibrated part 2 ml, cross section about 0.1 cme.Joints of one brand of glass, ground in. Special features: Cleaning by hot chromic acid mixture; apparatus kept in this medium until use.Bumping is prevented by the use of about 1 g of washed and dried pumice stones of = 2 mm. Creeping is prevented by the use of two glass wool mats, situated in the vertical tube, connecting still and receiver.Water vapour diffusing from and to the apparatus is caught in z set of moisture control tubes (Figures 1 and 3).The main water column and droplets possibly sticking to the glass walls are transported to the calibrated part of the receiver with the help of a defatted copper wire.Accuracy: Calibration on BaC1,. 2 H,O yielded a standard-deviation s = 0.010 g, corresponding to a coefficient of variation C = 1CP. s/ii = 0.55.The average discrepancy between calculated and measured values was 30 mg. "Constant" readings were reliable within less than 10 mg.Time required for reaching constant readings -7 h.In a previous paperl) it was concluded from a comparative appraisal, that of all available reference methods for water determination -with the exception of the Fischer-technique, which was .

show abstract

A New Moisture Tube

Cited by 9 publications

References 0 publications

Estimation of Moisture in Solventless Double-Base Powders

Estimation of Moisture in Solventless Double-Base Powders

Determination of Moisture in Cereals: Review of Methods in Common Use

Entrainment distillation as a reference method for the determination of the water content of foods: II. Development of a convenient method of entrainment distillation

Contact Info

Product

Resources

About