Magdas et al. 2012 — Isotopic and elemental profile of Romanian organic apple juices

This study characterized H, C, O stable isotope ratios and the concentration of nine elements (Cu, Cr, Ni, Zn, Pb, Co, As, Cd, U) in 31 organic single-strength apple juices from four Transylvanian regions of Romania (2010 harvest). The primary aim was building an authentic-value database for adulteration and authenticity testing of Romanian apple juice; the elemental occurrence data are presented as a parallel objective. Pb, Cd, total As, U, and Zn concentrations were below US-EPA drinking-water reference limits in every sample. Copper exceeded the 1000 µg/L drinking-water limit in one Alba sample (1224 µg/L). Chromium exceeded the 100 µg/L drinking-water limit in one Cluj sample (144.84 µg/L). Nickel exceeded the 40 µg/L drinking-water limit in some individual samples from Alba, Maramures and Cluj; the regional mean exceeded 40 µg/L only in Maramures (45.74 µg/L).

Key numbers

Concentrations in µg/L (ICP-MS, Perkin Elmer ELAN DRC-e). Values from Table 1 (regional min / max / mean over 31 single-strength juices):

Overall range across all 31 samples (Table 1-derived): Pb 0.02–11.02; Cd 0.14–1.06; tAs 0.18–1.14; U 0.02–0.52; Co 0.30–3.76; Ni 10.66–103.00; Zn 56.80–523.60; Cu 130.00–1224.00; Cr 10.60–144.84 (all µg/L).

Stable isotope ratios (IRMS, per V-SMOW for δ18O and δD, per PDB for δ13C):

• δ18O mean = −4.2‰; regional means range −3.7‰ (Maramures) to −4.5‰ (Cluj); individual values range −2.68‰ (Maramures) to −5.27‰ (Cluj).
• δD mean ≈ −46.5‰; regional means range −45.5‰ (Alba) to −49‰ (Maramures); individual values range −36.6‰ (Alba) to −53.5‰ (Maramures).
• δ13C mean = −28.2‰; regional means range −29.05‰ (Salaj) to −27.6‰ (Cluj); reported uncertainty ±0.3‰.

Sample basis is juice as-consumed (single-strength, neither concentrated nor reconstituted). To convert µg/L to ppb µg/kg multiply by approximately 1.04 (juice density ≈ 1.04 kg/L); the correction is negligible at the values reported.

US-EPA drinking-water reference limits cited by the authors for comparison: Cd 5 µg/L, Pb 15 µg/L, U 30 µg/L, Zn 5000 µg/L, Cu 1000 µg/L, Ni 40 µg/L, Cr 100 µg/L. Exceedance pattern in this dataset:

• Pb, Cd, tAs, U, Zn: all 31 samples below limits.
• Cu: 30 of 31 below; one Alba sample at 1224 µg/L exceeded the 1000 µg/L limit.
• Cr: 30 of 31 below; one Cluj sample at 144.84 µg/L exceeded the 100 µg/L limit.
• Ni: individual samples in Alba (up to 51.94), Maramures (up to 103.00) and Cluj (up to 81.40) exceeded the 40 µg/L limit; Salaj all below. Only the Maramures regional mean (45.74 µg/L) exceeded the limit.

Methods (brief)

Elemental concentrations measured by ICP-MS on a Perkin Elmer ELAN DRC-e quadrupole instrument with Meinhard nebulizer and silica cyclonic spray chamber. Sample preparation: 2 mL ultrapure HNO3 added to 2 mL juice in a Teflon receptacle, six receptacles sealed in a steel-cylinder digestion device and heated at 180 °C for 12 hours; resulting colorless solution diluted to 50 mL with ultrapure water (final dilution 1:20 v/v). Operating conditions: nebulizer gas flow 0.92 L/min, auxiliary gas 1.2 L/min, plasma gas 15 L/min, lens voltage 10.50 V, ICP RF power 1100 W, CeO/Ce = 0.023, Ba++/Ba+ = 0.021. Calibration used a Perkin Elmer Life and Analytical Sciences 10 µg/mL high-purity multielement standard (Al, As, Ba, Be, Bi, Ca, Cd, Co, Cr, Cs, Cu, Fe, Ga, In, K, Li, Mg, Mn, Ni, Pb, Rb, Se, Na, Ag, Sr, Ti, V, U, Zn) in 5% HNO3. Daily optimization used a 10 µg/L Ba, Cd, Ce, Cu, Co, In, Mg, Pb, Rh, U solution. Calibration linearity R > 0.998 for all nine analytes (Table 2). Reported relative standard deviations (%): Zn 14.44, Cu 34.33, Cr 7.57, Ni 2.75, Co 0.082, Pb 0.17, U 0.055, As 0.049, Cd 0.032.

Speciation: total arsenic only (no inorganic/organic As separation); no Hg, Sn, Al, Sb measured.

Isotope analyses: δ18O measured by IRMS (Delta V Advantage, Thermo Scientific) after CO2 equilibration of raw juice for 15 hours at 25 ± 0.1 °C per CEN:ENV 13141:1997; cross-checked against a Liquid-Water Isotope Analyzer DLT-100 (Los Gatos Research). δ2H measured by IRMS after static-vacuum distillation over Rittenberg trousers with quantitative water recovery. δ13C measured on dried pulp residue by Elemental Analyser (Flash EA1112 HT, Thermo Scientific) coupled to IRMS (Delta V Advantage). Calibration standard NBS-22 oil (certified value −30.03‰ versus Pee Dee Belemnite). Reported uncertainty ±0.3‰ for δ13C and δ18O, ±3‰ for δ2H.

Sample population: 31 single-strength organic apple juices pressed in-lab from fruit collected from four Transylvanian regions (Alba, Maramures, Salaj, Cluj) between 27 August and 19 September 2010. Varieties included Jonathan, Starkrimson, Golden, Melba, Legana, Classic Pippen, Stark Earliest, Voinea, and Generos. No per-sample disaggregation reported; results are summarised by region (Table 1) and by overall mean.

Implications

The dataset adds organic-apple-juice occurrence data for nine elements with Romanian regional disaggregation (Alba, Maramures, Salaj, Cluj). Pb and Cd are well below US-EPA drinking-water reference limits in every sample, with regional Pb means 1.56–3.42 µg/L and Cd means 0.28–0.43 µg/L. Total As is uniformly low (regional means 0.27–0.63 µg/L). Ni shows pronounced regional variability with the Maramures regional mean above the 40 µg/L drinking-water limit; the authors attribute Ni signal partly to fruit-processing contamination from contact materials (Section 3). Single-sample exceedances for Cu (1 Alba sample) and Cr (1 Cluj sample) suggest the upper tail of the occurrence distribution can rise sharply above the regional mean for these analytes.

Use for downstream products of this wiki:

• Adds non-US/non-EU regional occurrence data points for the apple-juice ingredient page contamination profile.
• Provides an A-tier source with explicit ICP-MS conditions for the methods literature on fruit-juice elemental analysis.
• Demonstrates the isotopic-fingerprinting plus elemental-profile combined approach used in juice authenticity work (relevant to courses on fraud detection and supply-chain verification).

Verification notes

This page was merge-enhanced on 2026-05-20 by re-reading the source PDF directly. Defects in the prior 2026-05-14 ingest corrected:

• Invalid product slug removed. Prior frontmatter listed [[products/fruit-juice]]; no such page exists in current taxonomy (snapshot 2026-05-18). Removed; valid slugs fruit-juice-not-canned and fruit-juices-apple-containing retained.
• raw_path corrected. Prior path was truncated to ...Apple Fruit.pdf; the actual file on disk is ...Apple Fruit Juices.pdf. Restored.
• Missing metals added. Prior metals: array was [Pb, Cd, tAs, Ni, Cr, U]. The paper reports nine elements (Cu, Cr, Ni, Zn, Pb, Co, As, Cd, U) in Table 1. Added Co, Cu, Zn to match the measurement scope.
• Range values corrected to match Table 1. Prior page reported “Cr 10.6–252 µg/L” and “Cu 35.6–1224 µg/L” in the overall range line. Those numbers come from the paper’s Conclusions narrative (page 5–6: “Cu 35.6–1224 µg/L, Cr 10.6–252 µg/L”), which does not reconcile with the regional min/max in Table 1. Table 1 yields Cr overall max 144.84 µg/L (Cluj) and Cu overall min 130.00 µg/L (Maramures). The Conclusions narrative also disagrees with Table 1 on Zn (narrative 47–523 vs Table-1 derived 56.80–523.60). Table 1 numbers are taken as authoritative because they are the structured per-region data; the narrative discrepancy is documented here rather than propagated. The corrected page reports Table 1 ranges throughout.
• Co range added. Prior page omitted Co (cobalt) entirely from the overall-range line. Added 0.30–3.76 µg/L (Conclusions narrative; matches Table 1 regional min/max).
• Legacy heading replaced. ## Wiki pages updated on ingest → ## Wiki pages this source touches per current schema.
• access_url added. DOI resolves directly to the open-access full text; added.
• Sample population expanded. Prior page named only the four regions and the harvest year. Added the collection date window (27 August – 19 September 2010) and the nine apple varieties from page 2.
• Methods expanded. Prior Methods (brief) was three sentences; expanded with the digestion procedure, ICP-MS operating conditions, calibration matrix, RSDs per analyte, isotope standards (NBS-22 oil, V-SMOW), and explicit no-Hg / no-Sn / no-Al / total-As-only speciation flag.
• Implications language softened. Prior page included App-audience risk-advisory framing (“may be relevant for sensitive populations”). Rewritten as occurrence-data contribution statements without consumer audience translation; threshold-comparison language is descriptive of the paper’s own US-EPA comparison, not a threshold proposal.

No brand names appear in this paper (no commercial brands sampled — the 31 juices were pressed in-lab from collected fruit). No Part 12 brand firewall issue. No Part 2 wiki/HMTc threshold proposals on the page.

Wiki pages this source touches

• lead
• cadmium
• arsenic
• nickel
• chromium
• uranium
• cobalt
• copper
• zinc
• apple-juice
• fruit-juice-not-canned
• fruit-juices-apple-containing

Page history

The five most recent substantive edits to this page. The full version history lives in git; when DOI minting comes online (see schema docs), each entry below will also link to a version-pinned DataCite DOI.