The first industrial applications - mainly for water, soil extracts and fertilizer - used the same hardware and techniques as clinical methods, but from the mid-1970s special techniques and modules were developed so that by 1990 it was possible to perform solvent extraction, distillation, on-line filtration and UV digestion in the continuously flowing stream.  In 2005 about two thirds of systems sold worldwide were for water analysis of all kinds, ranging from sub-ppb levels of nutrients in seawater to much higher levels in waste water; other common applications are for soil, plant, tobacco, food, fertilizer and wine analysis.