Speciation of inorganic and organometallic compounds in solid biological samples by thermal vaporization and plasma emission spectrometry

Abstract

By means of thermal Vaporization, Inorganic, organic, and metallorganic species are separated and elemental emission In a microwave plasma is detected as a function of vaporization temperature. Solid samples of 250 mg or more are used to avoid problems with sample heterogeneity. The precision of characteristic appearance temperatures Is ±2°C. The single electrode atmosphere pressure microwave plasma system Is extremely tolerant to the Introduction of water, organic solvents, and air. The measurement system contained a repetition wavelength scan device to allow background correction. The plasma temperature was 5500 K. The system was used to measure C, , N, O, and Hg In orchard leaves and In tuna fish. Speciation means the separation and determination of trace inorganic, organic, and organometallic species in real samples (1). The separation processes, which have been most useful for molecular species in solid samples, include volatilization and/or gas chromatography, extraction and partition chromatography, fusion and dissolution, and direct methods.

Tubular electrode torch for capacitatively coupled helium microwave plasma as a spectrochemical excitation source

“…Design Features. The present tubular electrode plasma torch design differs from the single electrode capacitatively coupled microwave plasma systems reported earlier (5-14, 30, 31) mainly in the way the sample is introduced in the torch and into the plasma. In the earlier CMP systems with aluminum or platinum-clad tungsten rod torches (5-14, 30, 31), the sample containing carrier gas was diffusively premixed with the plasma gas approximately 70-80 mm below the electrode tip.…”

“…With the use of a polychromator, all these lines could be simultaneously monitored and with calibration of emission channels for metal and nonmetal elements, it should be possible to speciate organotin compounds in the sample (30,31).…”

“…On the other hand, CMPs are stable over a wider range of powers (~200-1000 W) and can be sustained with a wider variety of plasma gases. The single Pt-clad W electrode atmospheric pressure microwave plasma (CMP) described by Hanamura et al (30,31) has considerably improved the performance of the CMP with respect to the single Al electrode CMP system described by Murayama et al (10)(11)(12). Furthermore, the Hanamura system could be operated with Ar, He, N2, and air at applied power from 400 to 560 W.…”

The use of different plasma gases (Ar, N 2 and air) for CMP-OES: figures of merit and temperature measurements

“…Indeed, with a CMP pneumatic nebulization without desolvation can be used for sample introduction and even aerosol obtained by the nebulization of organic solvents can be introduced without extinguishing the plasma. For that reason, this kind of plasma has been evaluated for different analytical purposes [1][2][3][4][5]. The strong matrix dependence of the N.H. Bings · J.A.C.…”

Determination of Inorganic and Total Mercury in Biological Tissues by Electrothermal Vaporization Inductively Coupled Plasma Mass Spectrometry

“…14 This technique has been applied to environmental samples 15 and rocks and sediments 16 using quartz tube AAS detection. As well as total Hg, direct methods for the speciation of mercury in soils and sediments 17 and biologicals 18 have been reported. ETV ICP-MS is well-suited for application to thermal vaporization methodology as the temperature of the graphite tube can be accurately controlled, small samples can be easily injected and the sampling frequency is relatively high.…”