Determination of Selenium by Atomic Absorption Spectrometry With Simultaneous Retention of Selenium(IV) and Tetrahydroborate(III) on an Anion-exchange Resin Followed by Flow Injection Hydride Generation From the Solid Phase

Abstract

Selenium(IV) and tetrahydroborate(III) (borohydride) were simultaneously retained on a strong anion-exchange resin in a packed column. Hydrogen selenide was generated by passage of an injected zone of hydrochloric acid with subsequent detection by AAS with quartz tube atomization. The limits of detection, defined as the concentration giving a signal equal to 3s of the blank, were 0.24, 0.15 and 0.12 mg l 21 of Se for 1, 2 and 3 min preconcentration at a sample flow rate of 3 ml min 21 , respectively. The precision of the procedure, expressed as the RSD of 10 successive determinations of 5, 10, and 20 mg l 21 of Se, varied from 0.41 to 1.32, 0.24 to 0.81 and 0.18 to 0.61% for 1, 2 and 3 min preconcentration, respectively. The system was used for the determination of selenium in river, lake and tap water matrices. No appreciable matrix effects were observed and the system was calibrated with aqueous solutions of a pure selenium salt (Na 2 SeO 3 ). The recoveries of spikes (0.5, 2, and 10 mg l 21 of Se) added to the water samples ranged from 96.0 to 102.0, 96.0 to 107.0 and 98.9 to 108% for river, lake and tap water, respectively.

Microtrace Metalloids Speciation in Lakes Water Samples (Poland)

“…In lake water of Wielkopolski Lake District including the reservoirs of Poznań and Gniezno City (1998) similar mean concentration of antimony at the level 0.50 ng/ml and in the range of 0.20 to 1.0 ng/ml was detected Niedzielski et al, ,b, 2003. In surface water concentrations of total selenium are at a level of tenths of ng/ml: 0.12 ng/ml (Carrero and Tyson, 1997), 0.15 ng/ml in Switzerland (Ornemark et al, 1992). Sea water in generally contains from 0.19 ng/ml (Kubota et al, 1995) up to a few ng/ml (e.g.…”

On-line preconcentration and determination of cobalt by DPTH-gel chelating microcolumn and flow injection inductively coupled plasma atomic emission spectrometry

“…The use of a preconcentration step is one of the more effective ways of increasing sensitivity. This operation can be performed in a flow injection system by coupling the latter on-line to a conventional separation unit, such as a minicolumn packed with a suitable sorbent [10] or ion-exchange material [11] or liquid-liquid extraction unit [12], before the detection system. Various supports have been used for the chelating groups, such as styrene-divinylbenzene copolymers [13], cellulose [14], silica gel [15], sepharose [16], and controlled-pore glass [17].…”

Determination of antimony by atomic absorption spectrometry with flow injection hydride generation by a tetrahydroborate-form anion-exchanger

“…12 However, due to the instability of aqueous solutions and the large volume required for both conventional batch and flow techniques, there is interest in the generation of hydrides from solid reagents. [13][14][15][16][17][18][19] Such procedures may also have decreased matrix interferences as the effective concentration of the borohydride is increased. Tian et al 13,14 developed a movable reduction bed hydride generator (MRBHG) for the determination of arsenic, antimony and selenium by coating a mixture of potassium borohydride and solid organic acid powders onto the surface of an adhesive tape.…”