Validation of inorganic arsenic detection methods using HPLC-ICP-MS and its contamination in market rice in Malaysia

The contamination of inorganic arsenic in rice has become worldwide concerned due to its associated with cancer effect. The demand for rice has forced farmers to apply pesticides to meet demand and prevent production loss especially on a large scale. The pesticide residue, particularly arsenic pesticides, has the potential to leach into the ground, leading to soil contamination and the presence of inorganic arsenic (iAs) in paddy seeds. However, reports on iAs contamination in Malaysian rice remain limited. Therefore, this study was performed to (1) to validate a reliable analysis for iAs (As (III), As (V)) in rice by using HPLC-ICP-MS and (2) to determine the iAs levels in local market rice using the established and validated method. The sample was grinded, sieved and grinded again until completely transformed to fine powder before analyse for total Arsenic (As) and iAs. The coefficient of determination (R2) calculation for the analytes was above 0.99. Also, the analytes exhibited a limit of detection at 0.002 mg/kg, including the limit of quantification of 0.005 mg/kg. Calibration standards were established in solution at 1.00μg/kg and 10.00 μg/kg. Recovery studies showed 93.74±6.43 (low concentration), 90.59±3.49 (medium concentration) and 89.63±3.42 (high concentration). The method was tested on the Food Analysis Performance Assessment Scheme (FAPAS) Proficiency Test sample and obtained a zscore of 1.09. Thus, the proposed method proved satisfactory for determining iAs in rice. The validated method was then tested on 23 rice brand variants, comprising of 15 imported and 8 domestic rice types. The convenience sampling approach was used as sampling technique. The recorded data was between 0.01 mg/kg and 0.102 mg/kg, where brown and coloured rice displayed 2 to 5 times higher iAs than white rice. None of the samples violated the Codex Alimentarius Commission (CAC) permissible level (0.20 mg/kg to 0.35 mg/kg) or the maximum permitted limit of European Union (EU) regulation (0.10 mg/kg to 0.30 mg/kg). In short, this study summarised that the level of iAs in rice available in the Malaysian market is generally low.

Text 122696.pdf Download (1MB) Official URL or Download Paper: http://ethesis.upm.edu.my/id/eprint/18634

Actions (login required)

View Item