Über die quantitative Bestimmung des Rubidiums und des Caesiums

Determination of the Common and Rare Alkalies in Mineral Analysis

“…The method of extracting rubidium and cesium chlorides from potassium chloride by means of hydrochloric acid and alcohol has been used by several analysts. Strecker and Diaz, however, in referring to this step (8) give no details of procedure, and the extraction of rubidium was found to be incomplete by Moser and Ritschel (3); they, however, used relatively large quantities of the two salts in their tests. Experience shows that efforts should be directed to dealing with small quantities of lithium, rubidium, and cesium.…”