Reczajska et al. 2005 — Chromium content of plant-origin foods and beverages in Poland

A total of 272 samples of fresh edible plants and beverages were analyzed for total chromium using electrothermal atomic absorption spectrometry with Zeeman background correction (ZETAAS) to assess dietary chromium from plant sources in Poland. Chromium content ranged from below 1 to 183 µg/kg fresh weight across solid foods, with the highest mean concentrations in wheat grains, strawberries, and cucumbers and values below the 1 µg/L detection limit in juices. Regional differences across three Polish provinces were observed, and results were generally lower than older Polish reference values, which the authors attribute to improved analytical methods that reduce contamination artifacts from earlier techniques.

Key numbers

Solid foods (µg/kg fresh weight), Table 4:

Beverages (µg/L), Table 5:

Regional breakdown (µg/kg fresh weight), Table 7:

Method performance: analytical range 0.05–10 µg/L; detection limit approximately 1 µg/kg (or 1 µg/L) for 1-g (or 1-mL) samples and approximately 2 µg/kg for 0.3-g samples; characteristic concentration 0.40 µg/L. Recoveries from spiked apple, canned potatoes-with-carrots, and beer matrices: 94 to 104 percent (Table 3).

Methods (brief)

Electrothermal atomic absorption spectrometry with Zeeman background correction (ZETAAS) at 357.9 nm, using a Varian SpectrAA 880 Z with GTA 100 graphite tube atomizer and PSD 100 sample dispenser. Solid samples (1.0 g fruits and vegetables, or 0.3 g wheat grain and reference material) were closed-vessel microwave digested with 4 mL concentrated HNO3 in Teflon PFA vessels using a CEM MDS 2000 microwave digester. Liquid samples (juices, beers, wines) were diluted with concentrated HNO3 (1 mL acid + 1 mL sample, brought to 25 mL with water) without digestion. Pyrocoated partitioned graphite tubes; palladium nitrate plus ascorbic acid matrix modifier; argon carrier; 10 µL injection. Standard additions, peak-area mode, six replicates per sample.

Quality assurance: certified reference material CTA-VTL-2 (Virginia Tobacco Leaves, IChTJ Poland) measured within certified limits at 3 percent relative standard deviation. Recovery study at spiking levels 100–500 µg/kg or µg/L returned 94 to 104 percent.

This paper reports total chromium only. Cr(VI) speciation was not performed.

Implications

Certification: Total Cr values in Polish fresh fruits, vegetables, and wheat grain from this 2001 survey are generally low — mean values below 40 µg/kg fresh weight for solid foods and below 13 µg/L for alcoholic beverages, with juices below the 1 µg/L detection limit. These are total chromium occurrence values; the source does not distinguish Cr(III) from Cr(VI). Per CLAUDE.md Part 14, total Cr values may not be carried as Cr(VI) without explicit speciation.

Courses: Illustrates two reusable points: geographic variation in chromium content within a single country (regional means differ by roughly a factor of two for strawberries and wheat across three Polish provinces), and the importance of contamination-controlled analytical methods (the authors note that older Polish reference values appear systematically higher because of pre-microwave sample-prep contamination).

App: Provides total Cr occurrence ranges for seven Polish plant commodities (strawberries, apples, cucumbers, cabbage, carrots, potatoes, wheat grain) and three beverage classes (wine, beer, juices). Confidence remains low until corroborating studies are integrated — this is a single 2001 single-country survey with total Cr only.

Verification notes

• Merge-enhance pass on 2026-05-19 of the prior 2026-05-14 page. The earlier version transposed two values from Table 5: Wines 90th percentile was recorded as 17 µg/L (the row’s RSD) when the source value is 14 µg/L, and Beers 90th percentile was recorded as 13 µg/L (the row’s RSD) when the source value is 8 µg/L. Both have been corrected against Table 5 of the original PDF.
• Strawberries range in source Table 4 prints “61–34”, which is a typographic artifact in the journal. Per the regional breakdown in Table 7, the actual species-wide range is 6 (lowest in Lubelskie) to 134 µg/kg (highest in Mazowieckie). The page records 6–134 with this reconstruction.
• Paper-internal contradiction noted but not edited away: the abstract and Table 4 both give a wheat-grain mean of 39 µg/kg, while the discussion text on page 3 writes 37 µg/kg in the same sentence as the strawberry and cucumber means. The 39 µg/kg value is carried since two of three source locations agree on it and Table 4 is the authoritative tabulation.
• Parallel paper-internal contradiction on potatoes: Table 4 gives a mean of 3 µg/kg while the discussion text on page 3 (“Apples, carrots, cabbages and potatoes contained smaller amounts of this element, mean values being 11, 6, 6 and 4 µg/kg respectively”) and the page-4 summary (“potatoes – 4 µg/kg”) both state 4 µg/kg. The page carries 3 µg/kg from Table 4 on the same Table-4-is-authoritative basis.
• Audit subagent (2026-05-19) flagged the Mazowieckie strawberries median (Table 7 row) as recorded “28” versus source “25”; verified against the page — the page records 25, which matches Table 7. Finding was a false positive; no change applied.
• Paper-internal sample-count discrepancy: the abstract states 272 total samples; the Materials section reports 224 fresh edible plants plus 30 beverages (254 total). The Table 4 column sums to 223 solid samples and Table 5 sums to 30 beverages (253). sample_n is carried at the abstract’s stated 272 with this discrepancy documented; no resolution is given in the source.
• Speciation discipline: this study measures total chromium by ZETAAS. The page records metals: [Cr], not Cr-VI. Cr(VI) requires explicit speciation (typically ion chromatography or co-precipitation), which this paper does not perform.
• Brand firewall: the source describes wines, beers, and juices as “purchased on the domestic market” with country-of-provenience grouping (Polish, European), and notes “large differences in Cr levels detected, even between food products of the same brand,” without naming any commercial brand. No brand-firewall edits were required.
• Wiki/HMTc firewall: page reports occurrence values and methodological context only. No threshold proposals or HMTc-alignment claims.
• Products field expanded on this pass beyond the prior [[products/fresh-fruit]] to add root-tuber-vegetables, non-root-vegetables, fruit-juice-not-canned, and fermented-beverages-non-tea-based, all from the current taxonomy snapshot. The routing layer fans the source out to its sibling product pages.
• Matrices normalized to the system-prompt vocabulary: root-vegetable, leafy-vegetable, cereal-grain, fruit-juice, wine, beer replace the prior less-canonical fresh-vegetable, grain, beverages triple.

Wiki pages updated on ingest

• chromium
• strawberries
• apples
• cucumbers
• cabbage
• carrots
• potatoes
• wheat

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.