RESUMEN
The consumption of rice milk has increased, mainly by individuals intolerant to lactose or allergic to cow milk. However, rice milk contains As. In this sense, the concentration of As in rice milk should be controlled. In the present study it is proposed a methodology for determination of As(III), dimethylarsenic (DMA), monomethylarsenic (MMA) and As(V) species in rice milk using LC-ICP-MS. The main features of the methodology are fast analysis, easy and simple sample preparation, where the sample is 3-fold diluted in the mobile phase and then filtered. The four arsenic species investigated were detected in the analysed samples, being As(V) the main species. The limit of quantification of the method ranges from 0.25 to 0.43⯵gâ¯L-1 As. The analyte recovery ranged from 81 to 116% for samples spiked to 1.00⯵gâ¯L-1 or 5.00⯵gâ¯L-1 As and the relative standard deviation was better than 5%.
RESUMEN
In this work, we investigated the stability of arsenic trioxide (ATO) used in leukemia treatment, encapsulated with nanoliposome, with the aid of ultrasound treatment. Stability studies of As species were followed by liquid chromatography-inductively coupled plasma mass spectrometry (LC-ICP-MS), allowing for the detection of the conversion of low amounts of As(III) to As(V) or the formation of other As species. The influence of storage temperature and time on ATO was evaluated. Low amounts of As(III) to As(V) conversions were observed when the As encapsulated with nanoliposome was incubated at 25 °C and 40 °C. However, As(III) was stable if the solution was maintained at 5 °C, even after 90 days. No formation of other As species was observed, indicating good stability of the encapsulated ATO. Next step of the work will focus on spray drying of ATO nanoliposomes-encapsuleted with the aim of long term stability of As.