Conservation Science for Cultural Heritage. Applications for Instrumental Analysis

Abstract

With AAS, it is possible to measure up to 65 elements with detection limits ranging from several ppm to a few ppb. The major strengths of AAS are the easiness of use, low detection limits, high specificity, low investment and minimal costs associated with it, well-documented interferences and methods for their elimination and access to a number of specialised techniques for the determination of non-metals and organic compounds. Flame and electrothermal atomization may be considered somewhat complementary techniques but while FAAS requires less operating skills, is faster, cheaper and less time-consuming, it also has poorer detection limits, especially for some refractory elements, cannot operate unattended and involves the use of larger sample volume. These pros outlined above made AAS one of the mainly used analytical techniques for cultural heritage studies in the past. The major disadvantages of AAS are the hard task to do qualitative analysis and the time-consuming limitation of having to analyse one element at a time. As compared with AES where all atoms in a sample are excited and can be detected simultaneously, one evident drawback of AAS is that it is inherently a single-element analytical procedure (multielemental analysis, although possible, is rather complex, see below for more details). Despite this drawback, AAS, due to its selectivity, simplicity and ease of use, is one of the most user friendly and least expensive techniques available for elemental quantification.