Speciation of arsenic in apple juice by LC-ICP-MS
The different physico-chemical forms of most elements vary in terms of mobility, toxicity and bioavailability. For example, arsenic species such as the inorganic trivalent arsenic (As III) and pentavalent arsenic (AsV) are highly toxic whereas the organic forms as monomethyl arsenic (MMA) and dimethyl arsenic (DMA) have significantly reduced toxicities. Reporting only the total concentrations can often be misleading.
When Liquid Chromatography (LC) is interfaced with Inductively Coupled Plasma Mass Spectrometry (ICP-MS), species elute one by one from the LC column directly to the ICP-MS for detection by elemental speciation. The coupling of LC to ICP-MS is a straight forward task; no hardware changes are required to either the LC or ICP-MS. The LC column is connected directly to the nebulizer of the ICP-MS. Coupling an LC to the PlasmaQuant® MS Elite has the added advantage of offering up to 5 times more sensitivity, offsetting the loss of total signal resulting from the separation of each species and providing very low part-per-trillion (ng/L) detection limits.
Fruits can be highly polluted with arsenic today, due to the use of arsenic based pesticides during the past century. The following experiment shows the sensitivity and detection capabilities of the PlasmaQuant® MS Elite for arsenic speciation in apple juice