Table 1.
Summary of recent microwave-assisted saponification (MAS) applications regarding hydrocarbon contaminants in food.
| Compounds and Food |
MAS Condition | Sample Post Treatment | Analysis | Recovery (%) | LODng/g (or mL) | Reference |
|---|---|---|---|---|---|---|
| EPA PAH Pumpkin seed oil |
1 g sample + 35 mL of 1.5 M KOH in methanol; microwaved at 130 °C for 10 min | LLE, SPE (on 0.5 g of silica gel) | GC-MS | >83 | [39] | |
| Aliphatic hydrocarb PAH Marine biota |
20 g sample + 50 mL ethanolic KOH (12%); microwaved at 600 W for 45 min (T max 85 °C) | MAE (3 × 40 mL n-hexane at 100 W for 12 min), LLE. SPE on 5 g Florisil | GC-FID | >90, except for lighter PAH | [40] | |
| 6 heavy PAH Fish and mussels |
1 g of fresh fish (or 0.2 g lyophilized + 0.8 mL of water) + 4 mL of saturated KOH in methanol + 10 mL of n-hexane; microwaved at 129 °C for 17 min. | SPE clean-up on silica gel (0.5 g) | HPLC-DAD/FLD | 85-100 except for IP, DBahA, BghiP* | 0.1–0.5 | [41] |
| 10 PAH Fish and mussels |
2 g of lyophilized sample + 12 mL saturated methanolic KOH + 12 mL n-hexane; microwaved for 15 min at 80% of the power | No sample post-treatment | GC-MS | 90–115, | [42] | |
| EPA-PAH Smoked fish and meat |
0.4 g of lyophilized sample + 1.6 mL of water + 8 mL of saturated KOH in methanol + 20 mL of n-hexane; microwaved at 120 °C for 20 min | SPE clean-up on silica gel (0.5 g) | HPLC-FLD | 75–109 | <0.1 | [13] |
| EPA-PAH Propolis and propolis- extracts |
0.2 g of propolis (or 0.5 g of propolis extract) + 8 mL of a saturated solution of KOH in methanol + 20 mL of n-hexane; microw. at 120 °C for 20 min | No sample post-treatment | HPLC-FLD | 91–102 | <0.1 | [43] |
| EPA-PAH Roasted plants |
0.4 g of lyophilized sample + 1.6 mL of water + 8 mL of saturated KOH in methanol + 20 mL of n-hexane; microwaved at 120 °C for 20 min | SPE clean-up on silica gel (0.5 g) | HPLC-FLD | <74 (for PAH8) | <0.1 | [44] |
| Mineral oils Cereal based products |
5 g sample + I.S.+ 10–20 mL saturated KOH in methanol (depending on the fat content) + 10 mL n-hexane; microwaved at 120 °C for 20 min | Rapid wash with water/methanol; follows sample concentration | on-line HPLC-GC | 89–104 (MOSH) 85–108 (MOAH) | 30 | [14] |
Abbreviations: LOD: limit of detection; EPA-PAH: Environmental Protection Agency–polycyclic aromatic hydrocarbons; GC-MS: gas chromatography–mass spectrometry; GC-FID: gas-chromatography–flame ionization detection; HPLC: high performance liquid chromatography–photodiode array detector/spectrofluorometric detection; SPE: Solid phase extraction; LLE: liquid-liquid extraction; FLD: spectrofluorometric detection.