Amino acids in sediments: Recovery by acid hydrolysis and quantitative estimation by a colorimetric procedure
Conventional hydrolysis of argillaceous sediments with 6 N HCl gave low recoveries of amino acids ; yields were increased considerably by prior destruction of clay with HF. Experiments with dried amino acid-clay complexes indicated that proteinaceous substances "keyed" into hexagonal holes on interlamellar surfaces of expanding-lattice clays may resist extraction with boiling 6 N HCl. A convenient and reliable colorimetric procedure was developed for the determination of amino acid - N in sediments. The technique is described in detail along with its application.