Arsenic and its compounds are known to have adverse health effects on humans, including cancers of the skin, bladder, kidney & lung, and diseases of the blood vessels of the legs and feet.  The toxicity of arsenic depends very heavily on their physico-chemical form.  Inorganic arsenic (arsenite, arsenate) containing ground water has caused tremendous epidemic poisoning across the globe.  Methylated forms of arsenic (MMA, DMA) are the most common metabolites of the human body and are found to be much less toxic.  

Some other arsenic forms which are very commonly presented and account for the majority of the arsenic abundance in the marine environment (arsenobetaine, arsenocholine, arsenosugars etc), are completely non-toxic.  The total concentration of arsenic cannot be used solely to explain the toxicity of arsenic in the environment.

P S Analytical offer both Agilent and Dionex options for the separation of arsenic species using the PSA 10.055 Millennium Excalibur as the detector.

PSA 10.825 ISOCRATIC LC SYSTEM (HPLC HG AFS) USED IN CONJUNCTION WITH THE PSA MILLENNIUM EXCALIBUR FOR THE SPECIATION OF ARSENIC

Up to four arsenic species; arsenite (AsIII), dimethylarsinic acid (DMA), monomethylarsonic acid (MMA) and arsenate (AsV) can be separated on a simple system. For the determination of non-reducible arsenic species such as arsenobetaine (AsB), arsenocholine and Trimethylarsine oxide ((TMAO) and arsenosugars; a PSA 10.570 UV oxidation system can be included.

This approach can be used for arsenic speciation in drinks, urine or any matrix after suitable extraction. Detection limits in the region of 0.2ng ml-1 are readily achievable. With excellent l.o.ds, and reproducibility toxic arsenic species can be measured easily on a routine basis.

This system consists of a 1200 series Isocratic pump, manual injection valve and solvent cabinet. By adding this system to a PSA 10.055 Millennium Excalibur, a PC and a suitable column the user has a powerful analytical tool for arsenic speciation.

The 1200 series pump is made of robust materials to withstand the most demanding of solvent compositions. The seal wash option for high salt mobile phases keeps maintenance to a minimum, thereby providing lower operational costs.

The system can be enhanced by the C723I009 ChemStation base software. This software is the industries' most widely sold data system

PSA 10.826 ISOCRATIC LC SYSTEM FOR THE SPECIATION OF ARSENIC

This system consists of a 3100 series Isocratic pump, manual injection valve and solvent rack. By adding this system to a PSA 10.055 Millennium Excalibur, a PC and a suitable column the user has a powerful analytical tool for mercury speciation.

The 3100 series pump is made of robust materials to withstand the most demanding of solvent compositions. The seal wash option for high salt mobile phases keeps maintenance to a minimum, thereby providing lower operational costs.

The system can be enhanced by the addition of Chromeleon software which offers control and data handling including integration facilities.
Other systems are available if additional facilities like degassing or quaternary mixing are required.

All of these systems provide the ideal platform for labs that need an easy-to-learn and easy-to-use system, which can be scaled up and extended as the labs needs grow.

Chromatogram of five injections of samples overlapped with a 10 ng ml^-1 mixed arsenical standards

Chromatogram of five Arsenic species obtained using HPLC-UV-HG-AFS

Determination of five arsenic species, arsenobetaine (AsBet), arsenite (AsIII), dimethylarsinic acid (DMA), monomethlyarsonic acid MMA and arsenate (AsV) was achieved by commercially available high performance liquid chromatography coupled to hydride generation and atomic fluorescence spectrometry (HPLC-HG-AFS). 

Arsenic containing human urine samples was filtered before being injected into a C18 column (PSA C2 or equivalent). Five arsenic species were separated using a phosphate mobile phase.

The eluted species were converted to volatile arsines by the addition of hydrochloric acid and sodium borohydride solutions. The volatile arsines were separated from the liquid phase using a gas-liquid separator and measured as arsenic using atomic fluorescence spectrometry. Excess hydrogen from the reaction of reagents provided the hydrogen diffusion flame which atomised the arsenic species.

The speciation of arsenic species including the non-reducible arsenic species (arsenobetaine and arsenosugars) requires the use of UV oxidation system.  This, in conjunction with an oxidising reagent, helps the breakdown of non-reducible arsenic species to a form that will react with NaBH4 so these can be quantified.  As a result, a slight modification to the system is necessary.

Naturally occuring inorganic and organic As species

To discuss particular requirements and for more detailed information on the above products please complete the Information Request Form.

For information on the speciation of Mercury, Selenium and Antimony please follow the appropriate link below:

Mercury

Selenium

Antimony