Altunay et al. 2023 — Cadmium in 13 Turkish market foods by FAAS, Sivas
Altunay et al. developed a vortex-assisted dispersive solid-phase microextraction (VA-dSPµE) method using a novel polyvinyl benzyl xanthate (PvbXa) adsorbent for ultra-sensitive cadmium determination by flame atomic absorption spectrophotometry (FAAS). The method was applied to 13 food commodities purchased from a greengrocer in Sivas, Turkey. Method LOD: 0.06 µg/L (in solution); LOQ: 0.20 µg/L; preconcentration factor 160; linear range 0.20–150 µg/L. The primary purpose is method development and validation, but Table 6 provides Cd concentrations in 13 real food matrices from Turkish market. The authors conclude results fall within WHO limits, stating no health risk.
Caution on reported values: The Cd concentrations in Table 6 are in µg/g (ppm), not µg/kg (ppb). For context, the EU MRL for Cd in cereals (including rice) is 0.1 mg/kg (100 µg/kg = 0.1 µg/g); for leafy vegetables it is 0.2 mg/kg. Several reported values in this paper — including onion at 2.08 µg/g (2080 µg/kg, 20× EU MRL for vegetables), spinach at 0.89 µg/g (8.9× EU MRL), salad at 1.15 µg/g, mushroom at 1.14 µg/g, white rice at 0.95 µg/g (9.5× the rice EU MRL) — are extraordinarily high compared to established surveillance data. The authors state results are within WHO limits, but do not show the comparison. These values are anomalously high relative to any peer-reviewed surveillance study in the literature. The values should be treated with caution; they may reflect a concentrating effect of the extraction procedure, matrix-specific interference, or a unit/dilution reporting error in the paper.
Key numbers
From Table 6 of the source (N=3 per food; mean ± SD). All in µg/g (= mg/kg = ppm).
| Food | Cd (µg/g) | EU MRL (mg/kg) | Apparent ratio to EU MRL |
|---|---|---|---|
| Apple | 0.47 ± 0.02 | 0.05 (fruit) | ~9× |
| Spinach | 0.89 ± 0.02 | 0.20 (leafy veg) | ~4.5× |
| Salad | 1.15 ± 0.03 | 0.20 (leafy veg) | ~5.8× |
| Tomatoes | 0.33 ± 0.01 | 0.05 (fruiting veg) | ~6.6× |
| Onion | 2.08 ± 0.06 | 0.05 (bulb veg) | ~42× |
| Oat | 0.71 ± 0.01 | 0.20 (cereal) | ~3.5× |
| Corn | 0.53 ± 0.02 | 0.05 (maize) | ~10.6× |
| Aubergine | 0.18 ± 0.01 | 0.05 (fruiting veg) | ~3.6× |
| Wheat | 0.95 ± 0.03 | 0.20 (cereal) | ~4.8× |
| Mushroom | 1.14 ± 0.04 | 1.0 (cultivated) | ~1.1× |
| Black rice | 0.80 ± 0.05 | 0.10 (rice) | ~8× |
| Brown rice | 0.65 ± 0.02 | 0.10 (rice) | ~6.5× |
| White rice | 0.95 ± 0.06 | 0.10 (rice) | ~9.5× |
These systematic EU MRL exceedances across diverse food types from a single local greengrocer are not consistent with typical survey data and warrant caution. If units were intended as µg/kg (ppb), white rice at 0.95 µg/kg would be well below the EU MRL and consistent with global reference ranges; that interpretation would require all values to be understood as 1000× lower than stated.
Methods (brief)
VA-dSPµE (PvbXa adsorbent) + FAAS (Shimadzu AAS-6300, D² background correction). Microwave digestion (HNO3/H2O2; Milestone Ethos; 200 °C, 1800 W). Method LOD 0.06 µg/L, LOQ 0.20 µg/L, preconcentration factor 160. CRM validation: INCT-TL-1 Tea leaves (98%), SRM-1547 Peach leaves (96%), SRM-1643e water (95%). Cd only; no other metals measured. Units in Table 6 stated as µg/g.
Implications
Certification: The reported Cd values in Turkish market foods are anomalously high relative to all peer-reviewed surveillance databases; systematic exceedances across diverse food types from one vendor suggest methodological artifact or unit reporting error. These values cannot be used directly in contamination profiles without reconciliation against other surveys.
Courses: Illustrates the importance of units and method validation in food surveillance; results incongruent with EU market data for the same foods across multiple categories simultaneously are a quality signal requiring investigation.
App: Do not use these values directly in contamination profiles pending resolution of the apparent anomaly. Flag as data quality issue.