Overview
Rumora Samarin and colleagues bought 58 rice samples in Zagreb and measured 29 elements by ICP-MS and four arsenic species by HPLC-ICP-MS. Mean total arsenic was 142 ug/kg dry weight and inorganic arsenic 89 ug/kg, higher in parboiled and brown rice than in white rice. Mean cadmium was 0.037, mercury 0.013 and lead 0.006 mg/kg dry weight.
Key numbers
- Inorganic arsenic (arsenite plus arsenate): white 72.2 ± 29.5, parboiled 118.3 ± 45.7, brown 106.0 ± 44.5 ug/kg dry weight (Table 1, p. 5).
- Total arsenic, all rice: 142.2 ± 57.1 ug/kg dry weight, range 36.7 to 259.0 (Table 1).
- Cadmium, all rice: 0.037 ± 0.035 mg/kg dry weight, range 0.002 to 0.208; lead 0.006 ± 0.012, range 0.003 to 0.090 (Table A1).
Methods (brief)
Rice milled as sold; elements by ICP-MS after microwave nitric acid digestion; arsenic species by anion-exchange HPLC-ICP-MS after dilute nitric acid extraction. NIST SRM 1568b rice flour gave good recoveries for total and species arsenic. Results on a dry-weight basis.
Evidence Fitness
A solid retail survey with speciation and reference-material QA. Weaknesses: no collection dates, origin counts that exceed the sample total, and lead and tin values clustered at a floor that looks like a substituted detection limit (flagged). For crisped-rice-cereal this is a proxy: it measures uncooked rice grain, not a puffed or crisped cereal.