The pattern of amino acids in seawater

In the last few years there have been considerable developments in the detection and quantification of amino acids in seawater. The pattern of amino acids found in the DFAA pool was believed in the past to be fairly uniform (see Dawson and Gocke, 1978) with a dominance of neutral amino acids (particularly glycine and serine). Fig. 7 was, in the past, considered to be a typical pattern for amino acids in seawater, including all artifacts arising from the desalting, concentration and transfer steps. 

It is likely that the advent of direct methods of analysis will also show that the absolute concentrations of amino acids in seawater have been overestimated. Few measurements exist for samples from the deep ocean and until further data are available, the lower limit for total free amino acids, as suggested by Lee and Bada (1975), whose techniques avoided any sample preservation, may be considered to be a reasonable estimate. 

At the present it is estimated that the concentration of dissolved combined amino acids lies 4 to 5 times higher than that of DFAA (Garrasi et al., 1979). 

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