Heavy metals in sediments have received increasing attention in recent years, partly because of the growing scientific and public awareness of environmental issues, and partly because of the improvement in the analytical techniques for accurately measuring their concentrations. Trace metal determinations in soils and sediments commonly involve some type of mineral acid extraction (wet oxidation...

1. The calf-thymus histone group F2a has been separated into two subfractions by stepwise precipitation with acetone from acid solution. 2. Carboxymethyl-cellulose and dextran-gel column chromatography and a method involving dialysis against ethanol have also given the subfractions, but the acetone-hydrochloric acid method has proved to be the most practicable. 3. The two subfractions differ si...

The highly specific feulgen reaction for demonstrating desoxypentose nucleic acid has proved to be of unequal utility in the hands of bacterial cytologists for the study of the bacterial nucleus (Milovidov, 1935), and at present the principal cytochemical evidence is derived from basic staining following hydrochloric acid hydrolysis or following ribonuclease digestion. It has been generally acc...

Lithium is becoming a strategic metal due to its important applications in secondary battery electrodes used in electronic appliances and also in electric traction vehicles. Lithium primary resources are brines and rock minerals, the former being nowadays almost exclusively used in the production of lithium commodities. With the expected increase in lithium demand, the development of competitiv...

The N-chloroacetyl and N-acetyl derivatives of some thirty racemic amino acids have been employed as starting materials for the subsequent enzymatic separation of the compounds into their opt.ical enantiomorphs (l-3).’ The procedure was always conducted in the absence of added buffer salts, the pH being set at 7 to 8 by addition of alkali to the aqueous solutions of the substrates. At the concl...

LHW (liquid hot water), HCl (hydrochloric acid) and NaOH (sodium hydroxide) were used to pretreat sugarcane bagasse (SB), and composition assay showed that the carbohydrate content in NaOH pretreated SB got to 84.3% and lignin decreased to 3.4%, while the LHW and HCl pretreatments brought similar composition changes, where the carbohydrate content reached 61.2% and 66.6%, respectively, and the ...

1. A crystalline enzyme capable of digesting yeast nucleic acid has been isolated from fresh beef pancreas. 2. The enzyme called "ribonuclease" is a soluble protein of albumin type. Its molecular weight is about 15,000. Its isoelectric point is in the region of pH 8.0. 3. Ribonuclease splits yeast nucleic acid into fragments small enough to diffuse readily through collodion or cellophane membra...

This paper describes an improved microwave digestion procedure for steel samples of various kinds intended inductively coupled plasma atomic emission spectrometry, including low alloy steel, stainless alloyed tool and high-speed steel. Their resulting solutions were used the simultaneous quantification elements together with several light boron, aluminum, silicon, phosphorous. Conventional meth...