Use of signal vs. time profiling to monitor sample volatilization in simultaneous multielement determinations by electrothermal vaporization/inductively coupled plasma atomic emission spectrometry

Abstract

The coupling of an electrothermal vaporlzer to an inductively coupled plasma spectrometer has been shown to result In a powerful technique. I n this communlcatlon we dlscuss the lmplementatlon of an electrothermal vaporlzer, a polychromator, and a data coilectlon routine that allows slmultaneous multlelement analysis. The trade-offs and conslderatlons necessary to recover the Information produced by the system In an optlmal fashlon are dlscussed. The method of data

Time gating for the elimination of interferences in electrothermal vaporization-inductively coupled plasma atomic emission spectrometry

“…Instrumentation. The 31-channel, 0.75-m Jarrell-Ash 965 AtomComp direct reading spectrometer, associated computer, electrothermal vaporization system, gas flow control, plotter, and modifications necessary to allow the acquisition of signal-vs.-time profiles have been previously detailed (18,20) Time Unless otherwise indicated the dry time was 30 s, the ash time was 2.5 s, and the atomize time was 3.3 s wavelengths used in this system include: Al I, 308.2 nm; As I, 193.6 nm; Fe II, 259.9 nm; II, 257.6 nm; Na I, 589.0 nm; and Pb II, 220.3 nm. Table I lists the plasma conditions and electrothermal vaporizer programs used in this study.…”

“…The electrothermal vaporizer (ETV) is a most useful device when coupled to ICP-AES systems (13)(14)(15)(16)(17)(18)(19)(20). Very small sample volumes are used and extremely low absolute detection limits have been achieved.…”

“…This results in an instantaneous, but high, concentration of analyte element in the plasma. By proper choice of measurement time, or time gating the detection system, the signal can be measured only during the time when the analyte is present in the plasma resulting in a relatively high signalto-noise ratio (16,18,20).…”

“…The appearance of various analytes from a multielement solution would be expected to follow the relative volatilities of the elements. When a multielement solution is introduced to an ETV-ICP-AES system, the retardation of plasma appearance time with decreasing volatility for the various components is demonstrated (20). Thus, some elements will pass through the plasma before the appearance of less volatile species.…”

Preliminary Investigation of Electrothermal Vaporization Sample Introduction for Inductively Coupled Plasma Time-of-Flight Mass Spectrometry

“…16 The result is, then, limited operation within a multielemental or scanning mode and the possibliity for erroneous quantitation. 17 A mass spectrometer, or spectrophotometer, [18][19][20] that provides simultaneous detection of all elements can be employed to eliminate this compromise between mass coverage and LOD/ precision for transient signals produced by ETV sample introduction. Furthermore, since the signals from all elements/isotopes are then collected at the same time, signal fluctuations and irreproducibility caused by the ion source, sample-loading procedure, or volatilization process can be eliminated through ratioing techniques and spectral skew limitations removed.…”