Simultaneous molecular and atomic spectrometry with electrothermal atomization and diode array detection

Abstract

Sir: Some papers dealing with the ultraviolet and visible study of molecular vapors produced by electrothermal atomizers were recently published (1-5). Various instruments were proposed depending on the aim of the work, from conventional flameless atomic absorption spectrometers (1-4) to dedicated equipment (5).Recently also the infrared range has been investigated, coupling an FT-IR spectrometer with a heated graphite atomizer, thus introducing further analytical applications of this device (6). At the same time new techniques have been developed for simultaneous multielement determination by graphite furnace atomic absorption (GFAA) or emission spectrometry (7)(8)(9).Considering these different applications, it seems advisable to explore the capability and behavior of electrothermal atomizers in acquiring, with the same equipment, molecular and/or atomic spectra for qualitative and quantitative analysis. This work reports some results obtained by a single instrument, made up of a graphite furnace and a diode array detector, in the ultraviolet investigation of vaporization phenomena of organic and organometallic compounds previously studied (2,4, 6).EXPERIMENTAL SECTION Apparatus. The equipment consists of a graphite furnace atomizer, Perkin-Elmer HGA-76 B, and Jasco KS-1Q0 M multispectrometer modified to meet the requirements of this study.The atomizer is equipped with an AS-1 autosampler, while solids are sampled as previously described ( 6). The spectrometer includes a deuterium source, polychromator, data processor, and recorder. Deuterium lamp, atomizer, and polychromator are mounted on an optical rail. The diode array of the polychromator (512 elements 25 pm wide) is a Reticon 512 S. The wavelength range (190-355 nm) is focused on the detector diodes by a concave holographic grating (500 lines/mm) blazed at 230 nm. A baffle inserted in front of the entrance slit of the polychromator reduces the detection of light emitted by the graphite furnace tube walls.The calculated resolution of the polychromator is about 0.3 nm/diode and the stray light is evaluated below 0.3%.The data processor can acquire up to 16 spectra with collection times varying from 0.05 s to 1 s and interval times from 0.05 s to 25 s. The spectra are transferred by RS-232 C interface to a Perkin-Elmer 7500 professional computer for absorbance calculation, data storage, and representation.Reagents. Crude oils, pigments, and polymers are examined in this work. The oils are diluted 1 to 10 with pure grade toluene. Pigment Blue 15 (copper phthalocyanine), Pigment Yellow 1 (monoazo derivative of 2-nitro-p-toluidine and acetoacetanilide), and Pigment Red 48:4 (Mn salt of monoazo derivative of 6amino-4-chloro-3-methylbenzenesulfonic acid and 3-hydroxy-2-

Continuum source atomic absorption spectrometry in a graphite furnace with photodiode array detection

“…RESULTS AND DISCUSSION Absorption Spectra. Absorbance spectra for several elements have been previously reported for a graphite furnace CSAAS experiment using a diode array for a detector (14,15). These works focused on simultaneous molecular and atomic absorption measurements; the resolution of the atomic lines was poor.…”

“…These works focused on simultaneous molecular and atomic absorption measurements; the resolution of the atomic lines was poor. Nevertheless, lead, copper, manganese, zinc, cadmium, vanadium, and nickel were determined in various crude oils and pigments (14), and matrix chloride interferences were characterized in the determination of copper and manganese (75).…”

Continuum source atomic absorption spectrometry and detector technology: A historical perspective

“…The further drawback arising from the sequential read-out of the array can be circumvented by means of a mechanical shutter. At first, linear PDA detectors were used in AAS for the study of broadrange background absorption in the graphite furnace [105,106]. By means of a D 2 lamp as continuum source the wavelength range from 190 nm to 350 nm could be covered with a bandwidth per pixel of a few hundred pm.…”

Identification of molecules in graphite furnace by laser ionization time-of-flight mass spectrometry: sulfur and chlorine containing compounds

“…It is also possible that larger clusters of sulfur existed which were responsible for the formation of S 1 and S 2 1 through fragmentation. Hearly et al 18 identified cationic sulfur by laser ablation and obtained a positive ion spectrum which showed a greater range of sulfur species from S 1 to S 11 1 . Larger clusters were reported to have existed over a small range of low laser power while S 1 dominated at high laser powers.…”

“…ETV with a continuous source of radiation and an ultraviolet (UV) multichannel detector spectrometer was employed recently for the systematic study of UV absorption spectra of inorganic compounds. [1][2][3][4][5][6][7][8][9][10][11][12][13] The setup was initially developed by Tittarelli et al, [1][2][3][4] and later improved by Daminelli et al [5][6][7] Investigations of alkaline earth fluorides and chlorides, [8][9][10] indium nitrate and Group 3 halides, 11 sulfides, sulfates and sulfur 12,13 were also carried out with this technique. The main objective of these studies was to identify species responsible for the absorption of the UV radiation.…”