Overview
Laizu bought 20 samples each of 20 vegetables at a Dhaka market and measured total arsenic, inorganic arsenic, monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA), plus inorganic phosphate. Root and tuber vegetables such as arum and carrot carried the most arsenic; leafy kolmishak and lalshak the least.
Key numbers
- Arum: total arsenic “3.9 ± 1.7”, inorganic arsenic 1.5 ± 0.9 µg/g (Table I; units from Results text).
- Parble: total arsenic 3.2 ± 2.9 µg/g, range 0.0 to 8.3 (Table I).
- Kolmishak: total arsenic 0.5 ± 0.2 µg/g (Table I).
Methods (brief)
Chopped vegetables were extracted in 50% methanol; arsenic species were separated on a cation-exchange column and quantified by silver diethyldithiocarbamate colorimetry. No detection limit, reference material or recovery is reported.
Evidence Fitness
A large sample set with arsenic speciation, but an old colorimetric method without quality control. Table I prints no unit and the text mixes µg/g and mg/g; values are recorded as µg/g, the only plausible reading, and the basis is taken as fresh. The levels are high for vegetables and should be weighed with caution. Individual vegetables are a proxy for vegetables-mixed: the paper does not measure a mixed-vegetable product, so it is not linked to that page.