Overview
Chen et al. developed a focused microwave digestion and atomic fluorescence spectrometry method for arsenic in edible fats and oils, then applied it to 21 market samples. The market-sample results ranged from 0.005 to 0.027 ppm arsenic, all below Taiwan’s 0.1 ppm maximum permissible concentration for edible fats and oils cited by the authors. The paper is useful both as total-arsenic occurrence evidence for fats and oils and as a method-validation source for oil-matrix digestion.
Key numbers
Market-sample arsenic results
Table 3 reports arsenic in ppm for edible fat and oil samples. The source does not report speciation, so these are total arsenic values.
| Matrix | Number of samples | Arsenic values (ppm) |
|---|---|---|
| Peanut oil | 2 | 0.006, 0.027 |
| Sesame oil | 2 | 0.006, 0.011 |
| Olive oil | 2 | 0.006, 0.012 |
| Sunflower oil | 2 | 0.005, 0.006 |
| Salad oil | 3 | 0.006, 0.007, 0.012 |
| Teaseed oil | 1 | 0.006 |
| Butter | 1 | 0.009 |
| Lard | 1 | 0.007 |
| Corn oil | 1 | 0.011 |
| Winter oil | 1 | 0.011 |
| Canola oil | 1 | 0.013 |
| Vegetable oil | 1 | 0.013 |
| Palm oil | 1 | 0.025 |
The source-stated overall range is 0.005-0.027 ppm arsenic across 21 samples.
Method validation
The atomic fluorescence instrument detection limit was 50 pg/mL, calculated as three times the standard deviation of twelve reagent blanks. The calibration curve used arsenic standards at 300, 500, and 700 pg/mL and reported Y = 0.2154X + 0.645 with R2 = 0.999.
Table 2 reports recovery for spiked samples:
| Added arsenic (ppm) | Palm oil recovery (%) | Olive oil recovery (%) | Lard recovery (%) |
|---|---|---|---|
| 0.025 | 89.8 +/- 3.5 | 86.4 +/- 4.1 | 86.9 +/- 4.1 |
| 0.050 | 93.0 +/- 3.2 | 92.0 +/- 3.7 | 91.2 +/- 3.5 |
| 0.100 | 94.7 +/- 2.9 | 96.9 +/- 3.5 | 91.5 +/- 3.3 |
Methods (brief)
The method weighed 0.5 g of fat or oil into a digestion vessel, added 10 mL sulfuric acid and 5 mL nitric acid, and used hydrogen peroxide during focused microwave digestion until the digest turned clear. The digest was diluted, treated with potassium iodide, reacted with hydrochloric acid and sodium borohydride to form volatile hydrides, and analyzed by hydride-generation atomic fluorescence spectrometry. The optimized conditions used 30% hydrochloric acid, 1% sodium borohydride, and argon carrier gas at 250 mL/min.
The occurrence data are total arsenic in source-reported ppm for edible fats and oils. The paper discusses arsenic species in general toxicology background, but the analytical method and results table do not speciate inorganic versus organic arsenic.
Implications
Certification: The study provides Taiwan-market total arsenic occurrence values for edible fats and oils. The data are useful for oil-matrix context but should not substitute for inorganic arsenic and should not be silently pooled with US-market oil benchmarks without a market decision.
Courses: Useful as a compact case study for oil-matrix digestion and hydride-generation AFS, including recovery data in palm oil, olive oil, and lard.
App: Adds low-level total arsenic context for several oil and fat categories. Matrices without exact ingredient pages, such as teaseed oil, salad oil, lard, winter oil, and palm oil, remain source-specific matrix descriptors rather than invented ingredient slugs.
Microbiome: Not addressed.
Related evidence
- Arsenic, Total
- Peanut Oil
- Sesame Oil
- Olive Oil
- Sunflower Oil
- Butter
- Corn Oil
- Rapeseed Oil
- Vegetable Oils
- Vegetable Oils
- Other cooking oils (canola, sunflower, coconut, avocado, sesame)
Update history
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