Luka and Akun 2019 - Trace metals in olive oils from northern Cyprus

Luka and Akun measured Cu, Cd, Pb, Cr, total As, and Ni in fifteen olive-oil observations from northern Cyprus using ICP-MS after microwave digestion. Table 5 reports variety/sample-code means in ug/g and shows broad variation by sampling group, with Cu ranging from 1.02 to 3.81 ug/g, Cd from 0.02 to 0.09 ug/g, Pb from 0.15 to 1.48 ug/g, Cr from 0.33 to 0.95 ug/g, total As from 0.03 to 0.75 ug/g, and Ni from 0.22 to 0.79 ug/g. The authors used PCA and hierarchical clustering to argue that oils from some ground-harvested samples accumulated higher metals, especially Cu, Pb, Ni, Cr, and total As.

Key numbers

Olive-oil metal concentrations

Table 5 reports mean +/- SD in ug/g with n=3. The source’s class labels are retained: a samples were harvested from the ground, b samples were harvested directly from the olive plantation, and c samples were from supermarkets.

The abstract gives the same overall ranges: Cu 1.02-3.81, Cd 0.02-0.09, Cr 0.33-0.95, As 0.03-0.75, Pb 0.15-1.48, and Ni 0.22-0.79 ug/g.

Quality-control data

Table 4 reports certified-reference-material recoveries for the measured elements. Found values were close to certified values: Cu 1965 +/- 20 ug/g vs certified 1963 +/- 20, Cd 5.25 +/- 0.02 vs 5.31 +/- 0.02, Cr 48.79 +/- 0.20 vs 49.3 +/- 0.60, Pb 10.04 +/- 0.04 vs 10.02 +/- 0.03, As 10.28 +/- 0.20 vs 10.25 +/- 0.10, and Ni 19.35 +/- 0.03 vs 19.49 +/- 0.04. The source reports recovery ranges from 98.8% to 100.3%.

Harvest and quality context

Table 3 reports free acidity, polyphenols, and fatty-acid parameters by harvest mode. Oils from olives harvested from the ground had higher free acidity (2.74% oleic acid) and lower polyphenols (15.16 mg/kg) than oils from plant-harvested olives (0.99% free acidity; 61.52 mg/kg polyphenols) or market samples (0.92% free acidity; 59.22 mg/kg polyphenols).

Methods (brief)

Samples were collected across northern Cyprus, including Gemikonagi, Kalavac, and Avtepe/Kelebrunu. Some oils were extracted from sampled olive fruits after crushing and n-hexane Soxhlet extraction, while other oil samples were collected directly from farmers after local cold pressing during 2017. The metal analysis digested 0.2 g olive oil with nitric acid in PTFE vessels using a Berghof microwave digestion system and analyzed Cu-63, As-75, Cr-53, Ni-60, Cd-111, and Pb-206 by Agilent ICP-MS.

The source reports total elements. Arsenic is total arsenic, chromium is total chromium, and lead/cadmium/nickel/copper are total elemental measurements. No inorganic arsenic or Cr(VI) speciation is reported.

Implications

Certification: This source provides northern Cyprus olive-oil occurrence evidence on a ug/g basis. Several Pb, total As, Cr, Ni, and Cu values exceed the source-stated threshold row, but the data should be used as Cyprus-market context unless a benchmark-pool decision admits non-US-market olive oil evidence.

Courses: Useful for teaching how harvest mode and post-harvest soil contact can affect oil quality and trace-metal patterns, with multivariate analysis separating higher- and lower-accumulation clusters.

App: Adds olive-oil category context for northern Cyprus. The values are not brand-specific and should remain at product/category and regional level.

Microbiome: Not addressed.

Wiki pages this source may touch

• copper
• cadmium
• lead
• chromium
• arsenic-total
• nickel
• olive-oil
• olives
• olive-oil
• cooking-oils-other

Verification notes

• PDF metadata, title page, and article footer identify the paper as Environmental Earth Sciences 78:578 with DOI 10.1007/s12665-019-8581-9, published online September 25, 2019.
• The PDF front matter shows Springer copyright but does not state an open license; frontmatter therefore records license: "not stated in PDF".
• The paper mentions that some samples include different brands, but no brand names are needed for this source page and none are reproduced.
• sample_n: 15 records the fifteen Table 5 observations. Table 5 reports each as mean +/- SD with n=3.
• The discussion says the As range is 0.03-0.75 ug/g and also states that values are below CODEX STAN 193-1995 at 0.1 mg/kg for As, Pb, and Cd. Because 1 ug/g is equivalent to 1 mg/kg, several Table 5 As and Pb values are above 0.1 mg/kg. This page preserves Table 5 and treats the broad “below Codex” statement as a source-side inconsistency.
• The source reports total arsenic and total chromium. These values must not be used as inorganic arsenic or Cr(VI).

Page history

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