Analytical potential of continuous precipitation in flow injection-atomic absorption configurations

Abstract

The Incorporation of a continuous precipitation unit built Into flow Injection manifolds Is presented and discussed, In order to show Its analytical potential in the development of Indirect automatic atomic absorption methods. The precipitate is formed by Injecting an anion (analyte) Into a carrier containing a cation (reagent) and Is retained on a stainless-steel filter. Two unsegmented flow configurations, one of which Involves the dissolution of the retained precipitate, have been tested. Three types of precipitates encountered In gravimetric procedures have been considered In this work: crystalline (calcium oxalate), curdy (sliver chloride), and gelatinous (ferric hydroxide). By continuous precipitation, chloride and oxalate could be determined In the range 3-100 )jg/mL and 5-90 Mg/mL, respectively, with a relative standard deviation between 2 and 5%. The sampling frequency ranges between 10 and 50 h~1.

Continuous Preconcentration of Sn2+/Sn4+by the On-line Sulfide Precipitation-Dissolution

“…Basic experimental system was the same as the one used before. 5 All water used was doubly distilled from the Milli-Q water system (Millipore, Bedford, MA, USA). The standard solution of Sn was made from pure Sn metal (99.999%, Alfa Prod.…”

Atomic spectrometric detectors for flow-injection analysis

“…This aspect of precipitation has been exten sively developed by the Cordoba research group and indirect methods for oxalate, chloride and hydroxide [96], chloride and iodide [97], chloride [98] and components of various pharmaceutical preparations [99,100] have been developed. These latter methods include local anaesthetics [99] and sulphonamides [100].…”

Atomic absorption determination of copper in silicate rocks by continuous precipitation preconcentration

“…Continuous precipitation systems were recently approached by the authors. Our earliest endeavors in this respect were aimed at the study of continuous automatic precipitationdissolution systems, coupled on-line with conventional atomic absorption instruments in implementing different methodologies such as indirect determinations of organic and inorganic anions and preconcentration of metal traces (14,15).…”