Hydride generation-in situ trapping-flame atomic absorption spectrometry hybridization for indium and thallium determination

Abstract

O desempenho analítico do acoplamento de geração de hidretos com sistema de aprisionamento de átomos (HG-IAT) em espectrometria de absorção atômica com chama (FAAS) foi avaliado para determinação de In e Tl em material de referência. Hidretos de índio (InH 3) e tálio (TlH) foram atomizados em sistema IAT aquecido em chama ar-acetileno. Investigou-se um novo arranjo da técnica hifenizada HG-IAT-FAAS, que superaria a capacidade operacional dos arranjos existentes (tubo de sílica resfriado com água, tubo de quartzo com dupla fenda ou "aprisionamento integrado"). Obteve-se significativa melhora nos limites de detecção, em relação às técnicas de aprisionamento de átomos acima citadas. Os limites de detecção, definidos como 3 vezes o desvio padrão do branco (3σ), foram 0,60 e 0,40 ng mL-1 para In e Tl, respectivamente. Para um tempo de pré-concentração de 120 s in situ (volume da amostra de 2 mL), a melhora na sensibilidade, comparando-se com espectrometria de absorção atômica com chama foi de 417 e 450 para In e Tl, respectivamente, usando a técnica de geração de hidretos e aprisionamento de átomos. A sensibilidade pode ser ainda melhorada aumentando-se o tempo de coleta. A precisão, expressa por RSD, foi de 4,4% e 5,2% (n = 6) para In e Tl, respectivamente. Os arranjos estudados incluíram tubo com fenda, tubo simples de sílica e aprisionamento de átomos resfriado e integrado. A precisão e exatidão do método foram verificadas pelo uso do material de referência certificado (GBW 07302 Sedimento) e soluções analíticas de calibração em meio aquoso. Os teores de In e Tl determinados no material de referência apresentaram adequada concordância com os valores certificados ou indicativos. The analytical performance of coupled hydride generation-integrated atom trap (HG-IAT) atomizer flame atomic absorption spectrometry (FAAS) system was evaluated for determination of In and Tl in reference material. Indium, using formation of InH 3 and TlH vapors were atomized in air-acetylene flame-heated IAT. A new design of HG-IAT-FAAS hyphenated technique that would exceed the operational capabilities of existing arrangements (a water-cooled single silica tube, double-slotted quartz tube or an "integrated trap") was investigated. A dramatic improvement in detection limits was achieved compared with that obtained using either of the atom trapping techniques, presented above, separately. The detection limits, defined as 3 times the blank standard deviation (3σ), were 0.60 and 0.40 ng mL-1 for In and Tl, respectively. For a 120 s in situ preconcentration time (sample volume of 2 mL), sensitivity enhancement compared to flame AAS, were 417 and 450 folds for In and Tl, respectively, using hydride generation-atom trapping technique. The sensitivity can be further improved by increasing the collection time. The precision, expressed by RSD, was 4.4% and 5.2% (n = 6) for In and Tl, respectively. The designs studied included slotted tube, single silica tube and integrated atom trap-cooled atom traps. The accuracy of the method was verified by the u...

Determination of lead by hydride generation atom trapping flame atomic absorption spectrometry

“…[41][42][43][44][45][46][47][48][49][50] In this study, we have demonstrated in situ trapping of lead hydride species on the inner walls of a flame-heated quartz tube under highly oxidizing flame conditions followed by the release of trapped species by introducing MIBK. The method is simple, cost-effective and yet offers the capability for the determination of lead at trace levels by FAAS.…”

“…46 Very recently, Matusiewicz and Krawczyk collected hydrides of As and Se by using an integrated atom trap (IAT) assembly consisting of a water-cooled single silica tube and a double-slotted quartz tube. 47 Shortly after this report, the group extended the application of IAT approach to the determination of Cd and Pb, 48 tellurium (Te), 49 and indium (In) and thallium (Tl) 50 by hydride generation FAAS. In this paper we described a conceptually similar approach of trapping lead hydride using a quartz tube atomizer for the determination of Pb by FAAS.…”

Improvement in thallium hydride generation using iodide and Rhodamine B

“…A characteristic concentration of 4 ng mL À 1 was obtained; this is a 1500-fold improvement on the sensitivity reported in the previous work [5]. As far as our review shows, there are only four additional reports on Tl chemical vapor generation (CVG), presumably as hydride [7][8][9][10]. Liao et al [7], extended the former research on the generation of TlH [5] in order to enhance the sensitivity for Tl determination using the in situ concentration of TlH in a graphite furnace coated with palladium.…”

Vapor generation and atom traps: Atomic absorption spectrometry at the ng/L level

“…The research group of Matusiewicz in Poland continues to study the development and application of integrated atom traps (IAT) in conjunction with vapor generation techniques; the device has recently been used for the determination of Cd and Pb [56], In and Tl [57], Te [58], Sb [59], Bi [60], As and Se [61]; in these studies a flame atomizer was used.…”

“…In this device, oxygen or air is admitted to the measurement zone through small orifices opened on the central axis by using a concentric double quartz tubing design [56,57]. Supply of the oxygen containing gas forms microflames at the orifices; hydrogen radicals are formed abundantly along the optical axis; linearity and freedom from interferences have been significantly improved.…”