Carotenoids

Abstract

The occurrence of carotenoids in recent sediments is typical of the geochemistry of any class of organic substances: it is primarily an analytical problem. Analysis of organic compounds in recent sediments is most challenging, and at the same time most frustrating. The difficulty of attempting to identify qualitatively or quantitatively trace quantities of organic material within a fantastically complicated matrix of other organic materials (most of whose make-up is still largely a mystery) is compounded by the fact that most often this organic matrix is itself a very minor component of an essentially inorganic system. Add to these purely chemical problems such insoluble questions as how to obtain a representative laboratory sample from an inhomogeneous sedimentary system many cubic kilometers in extent, or how to obtain from the field a sample sufficiently undisturbed so as to prevent chemical and especially biochemical changes. Pondered coldly and logically, such an analytical problem becomes insuperable and ought never be attempted. Yet, as a matter of fact, such attempts are made and, more surprisingly, often are made successfully. This chapter, then, will not simply enumerate the kind and quantity of carotenoids found in various sediments, but will try to investigate critically the literature of the subject and interpret it in light of the analytical problems involved and the techniques presently available.