A commercial arsenic field kit designed to measure inorganic arsenic (iAs) in water was modified into a field deployable method (FDM) to measure iAs in rice. While the method has been validated to give precise and accurate results in the laboratory, its on-site field performance has not been evaluated. This study was designed to test the method on-site in Malawi in order to evaluate its accuracy and precision in determination of iAs on-site by comparing with a validated reference method and giving original data on inorganic arsenic in Malawian rice and rice-based products. The method was validated by using the established laboratory-based HPLC-ICPMS. Statistical tests indicated there were no significant differences between on-site and laboratory iAs measurements determined using the FDM (p=0.263, ά=0.05) and between on-site measurements and measurements determined using HPLC-ICP-MS (p=0.299, ά=0.05). This method allows quick (within 1 hour) and efficient screening of rice containing iAs concentrations on-site.
Bibliographical noteThe authors express profound gratitude to the support of Commonwealth Scholarship funded by the UK government to Angstone Thembachako Mlangeni (MWCS-2015-334). The authors also acknowledges financial support from the Lilongwe University of Agriculture and Natural Resources (Malawi) for the field work. ATM acknowledges help and instrumentation technical support of Dr Edi Bralatei and Dr Magali Perez. ATM also acknowledges help and support of staff and farmers of Lifuwu, Bwanje, Domasi, Khanda, Baka, Nkondezi (Limphasa), Hara, Lufiriya, Kasinthuala, Nazolo and Nkhate research stations and rice schemes.
- field deployable method
- inorganic arsenic
- maximum contaminant limit