Speciation analysis and characterisation of arsenic in lavers collected from coastal waters of Fujian, south-eastern China.

Laver samples (Porphyra haitanensis) were collected from the coastal waters of Fujian province, south-eastern China and then the speciation characteristics of arsenic in the samples were studied in detail. These laver samples contained five arsenical species, namely arsenobetaine, monomethylarsonic acid, As(V) and two kinds of arsenic-containing ribosides (arsenosugars), with a relatively high concentration of total arsenic in the range of 28.85-63.03μgAs/g dried weight. DMAsSugarMethoxy was found to be the predominant species of arsenic in lavers, accounting for 90-98% of total arsenic. As3+ was not detected and the level of inorganic arsenic was much lower than the national tolerable average residue level (TARL), suggesting that the lavers are safe for consumption.