Indirect Determination of Phosphate, Silicate, and Arsenate by HPLC-AES

Abstract

The indirect determination of phosphate, silicate, and arsenate is performed by separation of their heteropoly acids by using ion-pair reverse-phase HPLC (IP-RPHPLC) and monitoring the molybdenum emission from a DCP with an echelle spectrometer and a charge-injection device (CID) detector. Limits of detection found for phosphate, silicate, and arsenate are 26, 31, and 52 ng/mL, respectively. The detection limit for arsenate is slightly degraded due to its proximity to the excess molybdate peak. These results represent an improvement in the determination for these nonmetals over results for direct aspiration into an emission source and show excellent linearity over three orders of magnitude.

Gold Nanoelectrode Ensembles for the Simultaneous Electrochemical Detection of Ultratrace Arsenic, Mercury, and Copper

“…The presence of arsenic or mercury in food and water above a certain level is a serious threat to public health, and therefore it is very essential to develop fast, sensitive, and selective analytical methods for their detection. Various methods including hydride generation atomic fluorescence spectrometry, inductively coupled plasma atomic emission spectrometry, inductively coupled plasma mass spectrometry, fluorescence spectrophotometry, atomic absorption spectrometry, etc., have been used for the detection of arsenic and mercury. – Although these methods are successful in detecting arsenic and mercury at subpicogram to subnanogram levels, they require expensive instruments, laboratory setup, and high operating cost . The low-cost electrochemical methods, particularly stripping voltammetry, have attracted significant interest for their excellent sensitivity and unique ability to detect the trace levels of elements in distinct oxidation states.…”

Improved simultaneous reaction-rate determination of phosphate and silicate by use of the continuous addition of reagent technique

“…The determination of phosphate and silicate in various types of sample is fairly commonplace in many analytical control laboratories. 1,2 Despite the widespread use of high-performance liquid chromatography for this purpose, [3][4][5][6][7] both equilibrium and reaction-rate methods based mainly either on the reaction of phosphate and silicate with molybdate in an acidic medium to form the corresponding yellow heteropolymolybdates or on their subsequent reduction to molybdenum blue are also widely used. The main drawback of these determinations is the mutual interference of both species, which strongly influences the performance of the ensuing analytical methods.…”

Flow Injection Analysis of an Ultratrace Amount of Arsenite Using a Prussian Blue-Modified Screen-Printed Electrode

“…For determination of arsenic species in natural water samples, highly sensitive and selective techniques are required. In recent years, the development of simple hydride generation atomic fluorescence spectrometer and inductively coupled plasma mass spectrometry (ICPMS) has provided methods for ultratrace arsenic determination. ,− These techniques, however, always need either off-line or on-line sample preconcentration and separation steps to offer sufficient detection capability. Furthermore, the interference by 40 Ar 35 Cl + , formed by plasma carrier gas with chloride ion and acid-derived background ions formed during the ion extraction processes, often causes serious error in ICPMS…”