Speciation studies using the P S Analytical Atomic Fluorescence Spectrometers – Easier than you think

The coupling of the PSA 10.820 MI with PSA’s Atomic Fluorescence Spectrometers significantly extends application capability from the detection of the total element concentration to the speciated forms.

This information is critical to determine bioavailability and toxicity of mercury, arsenic and selenium. Applications include the analysis of drinking water, food and drink, blood and urine as well as environmental samples such as waste water, soils and sediments.

The PSA 10.820 MI is configurable and may include; LC pump, injection valve, UV cracker as well as heating and cooling modules.

With a simple interface, and compatible flow rates, this accessory facilitates speciation studies (Hg, As, Se, Bi, Sb etc), online digestion (heat and UV), as well as a variety of post column reactions. The conjunction of the Atomic Fluorescence Spectrometers with the MI accessory provides ultimate detection performance for both sensitivity and selectivity.

In addition to the impressive detection performance, the automated approach significantly speeds up analysis times, reduces any sample pre-treatment and handling errors.

Arsenic Speciation

Speciation analysis of the five main arsenic species (arsenite, DMA, MMA, arsenate and arsenobetaine) is relatively simple and provides valuable information on sample toxicity. Arsenobetaine is extremely stable and does not easily react to form a volatile hydride. However, the heat and UV energy from the MI allows this species to be converted to the more reactive arsenate.

Selenium Speciation

Selenate (Se VI) does not react with NaBH₄ to form a volatile hydride, but can be easily converted to the hydride forming selenite (Se IV) with the addition of heat and chemical pre-reducing agents. Organoselenium compounds can be digested online with UV.

Mercury Speciation

Organomercury needs to be oxidised to inorganic Hg²⁺ prior to vapour generation and subsequent determination by atomic fluorescence. By applying heat and UV oxidation this reaction can be carried out in less than 1 minute.

P S Analytical is the leading company in the manufacture and supply of instrumentation for the analysis of Mercury (Hg), Arsenic (As), Selenium (Se), Antimony (Sb), Bismuth (Bi) and Tellurium (Te) in all matrices.