Determination of cadmium in biological materials by flame atomic absorption spectrometry with flow-injection on-line sorption preconcentration

Flow-injection on-line sorption preconcentration in a knotted reactor for electrothermal atomic absorption spectrometric determination of ultratrace amounts of cobalt in natural waters

“…Although successful applications have been made for FI on-line column preconcentration based on either ion exchange or solid sorbent extraction, there are still some limitations [15]. One of them is that due to high hydrodynamic impedance in the column it is impossible to use high sample loading flow rates.…”

“…These novel preconcentration systems were successfully applied to FAAS for the determination of cadmium in biological samples and copper in water and rice samples by Fang and co-workers [15,16]. In spite of difficulties in the direct coupling of FI online KR sorption preconcentration to ETAAS arising from the discrete non-flow-through nature of ETAAS, the limited capacity of the graphite tube, and the relatively large dead volume of the KR, the applications were also successfully extended to ETAAS for the automatic determination of lead in seawater by Sperling et al [17] and antimony (III) in water samples by Yan et al [18].…”

“…Compared with FI on-line column preconcentration systems, those based on the sorption of metaldithiocarbamate complexes on the inner walls of a PTFE knotted reactor (KR) allow the use of high sample loading flow rates for achieving high concentration efficiencies due to low hydrodynamic impedance in the KR and permit the analysis to be conducted at low cost due to the long lifetime of the KR and without the need for packing materials [15][16][17][18]. These novel preconcentration systems were successfully applied to FAAS for the determination of cadmium in biological samples and copper in water and rice samples by Fang and co-workers [15,16].…”

Multi-Element Analysis of Saline Matrices by Inductively Coupled Plasma Mass Spectrometry Following On-line Preconcentration Using a Knotted Reactor

“…Sorption onto knotted reactors (KRs) has several advantages, such as lower costs, longer lifetimes and reduced hydrodynamic impedances that permit higher flow rates compared to packed columns. Since its first applications by Fang and coworkers, 5 KRs made from open PTFE tubing have been widely used for on-line sorption of organo-metallic complexes or collection of precipitates, followed by subsequent elution and elemental analysis by atomic absorption methods (FAAS 6 and ETAAS 7 ). More recently, researchers have begun to explore the potential of KRs for preconcentration and matrix removal in multielemental techniques such as ICPOES [8][9][10] or ICPMS.…”

Extração líquido-líquido em sistemas de fluxo

“…Em termos de detecção, a espectrometria de absorção atômica tem sido citada com maior frequência, havendo ainda notificação do uso de outros detectores, como os de espectrofotometria UV-visível e eletrodos íon-seletivos [3][4][15][16][17] . Por outro lado, as técnicas de sorção (adsorção, troca iônica e extração líquido-sólido) têm ganho interesse dentre os procedimentos de pré-tratamento por AF nos últimos anos 3,5,[18][19][20][21][22][23][24][25][26][27] . O seu destaque deve-se provavelmente à facilidade de operação em relação às demais técnicas e à robustez dos equipamentos.…”