PS Analytical’s Arsenic Speciation solution provides laboratories with the ability to separate and quantify individual arsenic species instead of only measuring total arsenic content. Because the toxicity and environmental behaviour of arsenic compounds vary greatly depending on their chemical form, speciation gives much richer insight into health risks, environmental impact and compliance needs than total arsenic alone. Common target species include arsenite (As III), arsenate (As V), monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA) — with options to extend into other forms such as arsenobetaine and arsenocholine when needed.
The system combines chromatographic separation (e.g., HPLC) with hydride generation and atomic fluorescence spectrometry (HG-AFS) detection:
Separation: The arsenic species are first separated on a high-performance liquid chromatography column.
Conversion: As they elute, each species is converted to its volatile arsine form via reaction with a reducing agent (e.g., sodium borohydride).
Detection: The volatile arsenic arsines are swept into an AFS detector where they are quantified with ultra-high sensitivity — often at ultra-trace levels.
Optional UV oxidation: For species that do not easily form hydrides (e.g., arsenobetaine, arsenosugars), an online UV oxidation stage is included to convert them into detectable forms prior to hydride generation.
This aed workflow allows labs to determine multiple arsenic species in a single analysis, with minimal manual sample preparation and reduced handling errors compared with older bulk speciation methods.
The standard configuration of the arsenic speciation system can resolve and quantify up to four key arsenic species:
Arsenite (As III) — a highly toxic inorganic form
Arsenate (As V) — a common inorganic form with distinct toxicity
Monomethylarsonic acid (MMA) — an intermediate organic metabolite
Dimethylarsinic acid (DMA) — a less toxic methylated organic species
For broader arsenic profiles — including non-hydride-forming species like arsenobetaine — the system may be augmented with UV oxidation and extended chromatographic methods.
Drinking water and groundwater monitoring — distinguish toxic inorganic arsenic from less harmful organic forms
Food safety — speciate arsenic in rice, seafood and agricultural products
Environmental research — track arsenic transformation and mobility
Biomonitoring — measure arsenic metabolites in biological samples
Industrial monitoring — assess arsenic species in wastewater and process streams
