Analytical Chemistry

Figure 8.6

Working curve for the determination of magnesium with

molybdenum as internal standard.

over sixty can be determined simultaneously the technique has few rivals when a rapid qualitative
survey is required. It is ideally suited to the analysis of solid samples and finds widespread application
in the metallurgical industry for the analysis of alloys, in the semi-conductor and nuclear industries for
the detection of undesirable impurities, and in geochemical prospecting. Quantitatively, precision is
only moderate which is often not acceptable for the determination of minor and major constituents, but
because of extremely rapid processing of results by computer-aided direct reading spectrometers, the
technique is an invaluable aid in production

Table 8.3 Detection limits for a 1 mg sample in a dc arc using graphitc electrodes

Element Line measured, nm Detection limit, ppm

Ag 328.0 0.5

Al 394.4 1

B 249.8 1

Be 234.8 2

Cd 326.1 50

Co 340.5 5

Cu 327.3 0.1

Fe 302.0 10

Mg 285.2 0.01

Mn 279.4 2

Mo 313.3 5

Pb 283.3 10

Sn 284.0 5

Ti 337.3 5

V 318.4 10