Page 72 - Inorganic Mass Spectrometry : Fundamentals and Applications

62 3arshick

Analysis of National Institute of Standards and Technology (NIST) 685rW High
Purity Gold
Certified value GloQuad value Certified value GloQuad value
Element (PPm) (PPW Element (PP@ (PPm)
cu 0.1 0.02 Mg c0.2 c0.02
In 0.007 K0.006 Mn co.01 c0.03
Fe 0.3 0.3 N c0.03 <2
0 2 <0.4 Na d0.2 C0.08
Ag 0.1 0.03 Nb CO. l c=O.O01
A1 C0.03 <0.002 Ni c0.05 K0.02
Ba C0.03 <0.002 S K0.07 c0.07
C co.01 <2 se co.01 <0.001
Ca <l <0.6 Si C0.03 0.3
Cl CO. l <O.Ol Sn K0.07 c0.05
Cr c0.05 <a02 Sr c0.03 co.001
F c0.02 <40 v C0.05 <0.09
K <0.2 CO. l Zn c0.04 <0.01
Source: Ref. 118.

of Standards and Technology high-purity gold sample (Standard Reference Mate-
rial 658~). The general observation is that most of the measured values, includ-
ing those of transition elements, are present, or have bac~ground equivalent
concentrations (BECs), at the low part-per-billion levels. Elements that pose
particular problems when analyzed by a quadrupole inst~ment (primarily as a
result of interfering polyatomic species), such as Fe, Ca, Cl, Cr, K, Ni, S, and Si,
are present at or have BECs of less than 1 ppm (0.6 to 0.02 ppm). Meticulous
attention to gas purity resulted in obtaining much higher performance from a
quadrupole-based system than had previously been achieved.

or
Although gaseous discharges have been used in one form another for more than
80 years, it has been the developments the last 30 years that have been the major
of
benefit to analytical spectroscopists. The glow discharge’s strengths are well
established now, and new applications, like those highlighted in this chapter and in
other chapters in this book, keep pushing the technique new areas as a tool for
into
solving problems in the chemical sciences. Novel instrumentation, like the ion
trap and the time-of-flight, promise new and exciting opportunities for GD
and developments with new and existing sources oEer the hope that the technique