Arsenic Speciation in Honeysuckle (Lonicera japonica Thunb.) from China

In this study, honeysuckle, a common Chinese herbal medicine, produced from different areas was investigated for total arsenic and arsenic species concentration. The total arsenic concentrations were determined by inductively coupled plasma mass spectrometry (ICP-MS) and ranged from 275 to 635 μg kg(-1). A microwave-assisted procedure with 1 % phosphoric acid (v/v) was used for the extraction of arsenic species in honeysuckle. The total arsenic species concentration found by liquid chromatography-inductively coupled plasma mass spectrometry (LC-ICP-MS) was in agreement with the total arsenic concentration determined by the ICP-MS analysis after the microwave digestion. Arsenate (As(V)) with an average proportion of 54.3 % was the predominant arsenic species in honeysuckle. The order of concentration is as follows: As(V) > arsenite (As(III)) > dimethylarsinic acid (DMA) > arsenobetaine (AsB) > monomethylarsonic acid (MMA). The proportion of organic arsenic (24.7 %) was higher than that in most terrestrial plants. Moreover, the distributions of arsenic species in the honeysuckle from different producing areas were significantly different. This study provides useful information for better understanding of the distribution of arsenic species in terrestrial plants.