This analytical chemistry paper developed a fluorescence method for cerium and applied it, alongside ICP-OES, to market foods, human fluids, soils and bones from Bangladesh. The food values are high (several to about 20 mg/kg) and come from one sample per food analyzed five times, so they illustrate the method rather than characterize the food supply.
Key numbers
- Method detection limit 0.1 ng/L and quantification limit 1 ng/L in solution; linear range 0.001 to 600 µg/L as printed (abstract, p. 1).
- Cerium in market foods by the proposed method (mg/kg, mean of five replicate analyses of one sample): carrot 21.8, mango 16.8, arum 15.5, wheat 12.8, potato 11.5, radish 10.9, rice 10.1, spinach 9.8, corn 9.5, cabbage 7.5; ICP-OES values were similar, for example 20.5 for carrot and 8.5 for spinach (Table 10, p. 14). The basis is not stated; samples were oven-dried before digestion.
- Cerium in single patient samples (ng/L, proposed method): blood 152.5 to 430.0, urine 42.8 to 110.8; milk from one lactating mother 58.6; hair of one woman 2.5 µg/g (Table 7, p. 13).
- Surface soils from industrial, agricultural and roadside sites: 21.8 to 135.8 mg/kg (Table 8, p. 13).
Methods (brief)
Cerium(III) in digests was oxidized to cerium(IV), which oxidizes the compound PTQA in slightly acidic ethanol to a fluorescent product measured at 303/370 nm. Foods were washed, oven-dried at 65 degrees C, ground and acid-digested; certified reference materials (including wheat flour and noodles) and ICP-OES comparison were used for validation.
Evidence fitness
Supports method performance claims and shows that a fluorescence approach agreed with ICP-OES in these matrices. The food and fluid values are single samples without stated moisture basis, so they cannot support statements about typical cerium in foods or people.
Limitations
One sample per food or person; basis (dry or fresh weight) not stated for foods; samples from a small area; patient samples are not a population sample.
Related evidence
- Rare Earths
- Fluorescence sensors for metals
- ICP-OES — optical emission spectrometry
- Carrot
- Rice
- Wheat
Update history
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