A short survey of semiquantitative methods of analysis and some new contributions

The definition and use of non-sophisticated semiquantitative methods in analytical chemistry are described. The most important principles for such techniques are discussed: colorimetry, comparison of time, counting of portions, identification limit, area, temperature, volume of precipitate. Some new methods are proposed: strip methods with three different volumes or with three different reagents, an 8-channel colour comparator, titrations with and on impregnated paper, and an evaporation method. Examples are given for the estimation of various ions in the microgram or nanogram range.