In the field of plant analysis there is a confusing variety of methods and procedures, both for digestions and determinations. In many cases the digestion and the subsequent determination are interrelated. For example, a separate digestion is needed for trace elements in order to obtain determinable concentrations. The authors have chosen a design in which the digestion/extraction procedure is described in one chapter together with all determination procedures that may be carried out on that particular digest/extract. All the necessary information (such as standardizations) appears in appendices. As a consequence, several determination procedures are described two or three times, however, each based on a particular digestion or extraction method.
Two types of determination procedure are described: manual and automated. Manual procedures are mainly used in research laboratories, whereas automated procedures are more frequently applied in routine laboratories. Both types of determinations can be used freely, provided that appropriate equipment is available. The determination procedures are only for inorganic components, usually elements. Besides, most procedures are designed to give a total content value of the element under consideration, regardless of the chemical structure in which it occurs in the plant.
The Plant Analysis Manual is intended for the practicing (agricultural) chemist.
1. Digestion in tubes with H2SO4 - salicylic acid - H2O2 and selenium: Ca, K, Mg, Mn, N-total, Na, P, Zn.
2. Digestion in flasks with H2SO4 - salicylic acid - H2O2: Ca, Ka, Mg, Mn, N-total, Na, P, Zn.
3. Digestion with HNO3 - HClO4 - H2SO4: Al, Cd, Cu, Fe, Mn, Pb, Zn.
4. Digestion with HNO3: S-total.
5. Extraction with HNO3 - H2O2 - HF: Al, Cd, Cu, Fe, Mn, Pb, Zn, ...
6. Digestion by dry-ashing followed by treatment with HF: Ca, Cd, Cu, Fe, K, Mn, Na, Pb, Zn.
7. Digestion by dry-ashing in the presence of CaO: B.
8. Extraction with water: Cl, NO2, NO3, SO4.
9. Extraction with water in the presence of Ag and Cu: NO3.
10. Extraction with HF - HCl: B, Si.