No abstract

No abstract

No abstract

No abstract

Sample preparation techniques have experienced an explosive development during the past decades. Procedural approached that uses minimal sample amounts reducing to the limit and sometimes eliminating completely the use of toxic and/or environmentally unfriendly solvents and reagents have emerged as standard in the analytical laboratory. At the same time, significant improvements in sensitivity and selectivity have appeared. This article revisited the principal developments of sample preparation methods for analytical determinations as produced recently. The approach is systematic, classifying the procedures into two broad groups: methods based on equilibrium and exhaustive methods. In each case, the principal methods are revisited with a brief description about the principles and chemistry involved and some examples in each case. A large number of bibliographic references allow a deeper study on each case, when necessary.