EXTRACTION OF EXCHANGEABLE CATIONS FROM WYOMING BENTONITE SUSPENSIONS

1965 ◽  
Vol 45 (1) ◽  
pp. 39-48 ◽  
Author(s):  
J. S. Clark
Keyword(s):  
Exchangeable Cations ◽  
Base Saturation ◽  
Theoretical Base ◽  
Salt Solutions ◽  
Single Extraction ◽  
Wyoming Bentonite

Wyoming bentonite suspensions were prepared with a range of per cent Ca saturations and the exchangeable cations were extracted with solutions of NaCl, KCl, NH4Cl, and CaCl2. The per cent base saturation values, (Ca/Ca+Al)) × 100, obtained both by serial extraction with 1 N salt solutions and by a single extraction with 2 N NaCl or KCl agreed closely with the theoretical base saturation values calculated from the corrected lime potential. Somewhat better agreement with the theoretical values was obtained, however, with a single extraction than by serial extraction. The sum of Ca + Al (effective C.E.C.) was less affected by changing extract to clay ratio when a single extraction was employed. For these reasons, it was concluded that a single extraction with 100 ml of 2 N NaCl or KCl for 0.5 to 2.5 meq of exchange sites should be employed for the determination of exchangeable cations in clays and soils.

THE EXTRACTION OF EXCHANGEABLE CATIONS FROM SOILS

1965 ◽  
Vol 45 (3) ◽  
pp. 311-322 ◽  
Author(s):  
J. S. Clark
Keyword(s):  
Soil Ph ◽  
Experimental Error ◽  
Colorimetric Method ◽  
Soil Samples ◽  
Exchangeable Cations ◽  
Base Saturation ◽  
Ion Concentrations ◽  
Ph Values ◽  
Exchangeable Al ◽  
Wyoming Bentonite

A study was made of techniques for the measurement of soil pH and corrected lime potential and for the extraction of exchangeable cations from soils. The experiments showed that in order to obtain stable and reliable pH values and ion concentrations it was necessary to equilibrate the soil samples in CaCl2 (0.005 to 0.02 M) for 4 to 5 days. After the soil was washed twice with water, the exchangeable cations were extracted from the equilibrated samples by shaking for 16 to 24 hours with 100 ml 2 N NaCl for 0.5 to 2.5 meq of exchangeable cations. In order to obtain reliable values for exchangeable Al with the soils studied, it was necessary to use a colorimetric method instead of titration with NaOH. When these precautions were observed the relation between corrected lime potential and percent base saturation for a number of soils agreed within reasonable experimental error with the theoretical one obtained for Wyoming bentonite.

scholarly journals Classification of brown earths based on field and laboratory properties: Problematic issues and proposition of their solution

2019 ◽  
Vol 52 (2) ◽  
pp. 225
Author(s):  
Karolina Woźnica ◽  
Agnieszka Józefowska ◽  
Justyna Sokołowska ◽  
Ryszard Mazurek ◽  
Tomasz Zaleski
Keyword(s):  
Calcium Carbonate ◽  
Main Parameter ◽  
Ph Value ◽  
Soil Classification ◽  
Base Saturation ◽  
Carbonate Content ◽  
Field Guide ◽  
Content Determination

<p class="Default">In this paper, the current problems associated with the classification of brown earths, are presented. According to the Polish Soil Classification (PSC) (1989, 2011), base saturation is the main parameter for identifying eutrophic and dystrophic brown soils. In practice, however, it is not possible to determine the base saturation value in the field. Therefore, the aim of this study was to estimate the base saturation using a regression equation and create a field guide for brown earths, based on the pH value, measured using a Hellige indicator, and the calcium carbonate content. Determination of the pH ranges enabled the classification of brown earth types in the field. These results suggest that pH can be used as a proxy for base saturation especially in the field. A change in the hierarchy of soil (sub)types is proposed for the new Polish Soil Classification.</p>

Erythrocyte porphyrin analysis in the detection of lead poisoning in children: evaluation of four micromethods.

1976 ◽  
Vol 22 (2) ◽  
pp. 161-168 ◽  
Author(s):  
T L Hanna ◽  
D N Dietzler ◽  
C H Smith ◽  
S Gupta ◽  
H S Zarkowsky
Keyword(s):  
Acetic Acid ◽  
Ethyl Acetate ◽  
Lead Poisoning ◽  
Complete Recovery ◽  
Comparison Method ◽  
Working Standard ◽  
Single Extraction ◽  
Double Extraction ◽  
Poisoning In Children

Abstract We evaluated four procedures for determination of erythrocyte porphyrin: double extraction with ethyl acetate/acetic acid-HCl, single extraction with ethanol, single extraction with acetone, and direct solubilization with detergent-buffer. The ethyl acetate procedure, when used with two portions of HCl, apparently gives complete recovery of porphyrin and is suitable for reference as a comparison method. The ethanol procedure gives a high and consistent recovery and is technically simpler. The acetone procedure gives low and variable recovery of porphyrin, and the detergent-buffer method is subject to serious hemoglobin interference; neither of these two procedures offers any technical advantage. Stability of samples and methods for standardization were explored. A procedure for expressing results in terms of erythrocyte Zn-protoporphyrin content is given. Because of its stability, coproporphyrin is useful as a daily working standard. The ethyl acetate and ethanol methods are about equally efficient for detecting lead intoxication. Because of its simplicity, the ethanol method seems to be the best for use in screening.

Simultaneous Determination of Trimethadione and Its Metabolite, Dimethadione, by Gas—Liquid Chromatography

1971 ◽  
Vol 17 (7) ◽  
pp. 607-609 ◽  
Author(s):  
H E Booker ◽  
B Darcey
Keyword(s):  
Liquid Chromatography ◽  
Simultaneous Determination ◽  
Major Metabolite ◽  
Gas Liquid Chromatography ◽  
Single Extraction ◽  
Chromatographic Procedure

Abstract A simple gas chromatographic procedure is described for the measurement of trimethadione and its major metabolite, dimethadione, in serum. The method, with which compounds can be determined on a single extraction and injection, is reliable and free from interference caused by other drugs, particularly those that the patient is likely to be taking in combination with trimethadione.

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