Table 1.
Disposable medicinal and food/beverage containers tested for oleamide leaching by the LC-MS method together with the estimated intake of oleamide per volume of the tested material. Data for the concentration of oleamide in extraction media represent means ± standard deviation (SD) (n = 3); paired t-test with * p < 0.05; ** p < 0.01; *** p < 0.001 compared to blank.
| Material Tested with LC-MS Method | Type of a Polymer | Extraction Media/Type of Simulant | Contact Conditions | Pre-treatment before Analysis | Presence of Oleamide Peak in SIM (m/z 282) | Concentration of Oleamide in Extraction Media (ng mL−1) | Estimated Intake of Oleamide (µg) Per Volume (mL) of the Tested Material |
|---|---|---|---|---|---|---|---|
| Medicinal plastic material | |||||||
| Intravenous infusion bottle A | LDPE | S (EtOH10) | 10 days, 60 °C | conc. | + | 17 ± 1 *** | 4/250 |
| Syringe 5mL B | PP + PE | MeOH | non conc. | + | 7351 ± 1963 * | / | |
| Syringe 5mL B | PP + PE | S (H2O) | conc. | + | 12 ± 3 ** | 0.06/5 | |
| Syringe 5mL C | PP + PE | MeOH | non conc. | - | <LOQ | / | |
| Syringe 5mL C | PP + PE | MeOH | conc. | + | <LOQ | / | |
| Syringe 5mL C | PP + PE | S (H2O) | conc. | - | <LOQ | / | |
| Insulin syringe 1 mL D | PP | MeOH | non conc. | + | 21,984 ± 1155 *** | / | |
| Insulin syringe 1 mL D | PP | S (H2O) | conc. | + | 152 ± 8 *** | 0.15/1 | |
| Insulin syringe 1 mL B | LDPE | MeOH | non conc. | - | <LOQ | / | |
| Insulin syringe 1 mL B | LDPE | MeOH | conc. | - | <LOQ | / | |
| Insulin syringe 1 mL B | LDPE | S (H2O) | conc. | - | <LOQ | / | |
| Enteral syringe E | PP | MeOH | non conc. | - | <LOQ | / | |
| Enteral syringe E | PP | MeOH | conc. | + | <LOQ | / | |
| Enteral syringe E | PP | FS (EtOH50) | conc. | - | <LOQ | / | |
| Baby bottles | |||||||
| Baby bottle F | PP | FS (EtOH50) | 2 h, 40 °C | conc. | + | 23 ± 3 ** | 3/125 |
| Baby bottle G | PP | FS (EtOH50) | 2 h, 40 °C | conc. | + | 12 ± 2 ** | 3/250 |
| Baby bottle H | PP | FS (EtOH50) | 2 h, 40 °C | conc. | + | 20 ± 2 ** | 6/300 |
| Dummy F | silicon | MeOH | conc. | + | 33 ± 8 ** | / | |
| Dummy G | silicon | MeOH | conc. | + | 30 ± 4 ** | / | |
| Dummy H | silicon | MeOH | conc. | + | 39 ± 9 ** | / | |
| Plastic food containers | |||||||
| Carbonated soft drink I | PET | FS (AC3) | 10 days, 60 °C | conc. | + | 15 ± 3 ** | 8/500 |
| Carbonated soft drink J | PET | FS (AC3) | 10 days, 60 °C | conc. | + | 6 ± 1 ** | 9/1500 |
| Vitamin water K | PET | FS (AC3) | 10 days, 60 °C | conc. | + | 15 ± 3 ** | 8/500 |
| Milk (3.5% fat) L | PET | FS (EtOH50) | 10 days, 20 °C | conc. | + | 3 ± 2 * | 3/1000 |
| Milk (3.5% fat) M | PET | FS (EtOH50) | 10 days, 20 °C | conc. | + | 9 ± 5 * | 9/1000 |
| Milk (1.5% fat) N | PET | FS (EtOH50) | 10 days, 20 °C | conc. | + | 8 ± 3 * | 8/1000 |
| Liquid yogurt (4% fat) O | PET | FS (EtOH50) | 10 days, 20 °C | conc. | + | 17 ± 3 ** | 9/500 |
| Liquid yogurt (1.3% fat) P | PET | FS (EtOH50) | 10 days, 20 °C | conc. | + | 17 ± 2 ** | 8/500 |
| Oil N | PET | FS (oil = RS) | 10 days, 60 °C | LLE + conc. | + | 238 ± 21 ** | 238/1000 |
| Milk (3.5% fat) M | PET | RS (milk) | LLE + conc. | + | 293 ± 47 * | 293/1000 | |
| Oil N | PET | RS (oil) | LLE + conc. | + | 217 ± 9 *** | 217/1000 | |
| Water Q | PET | RS (water) | 10 days, 60 °C | conc. | + | 16 ± 2 ** | 8/500 |
| Water R | PET | RS (water) | 10 days, 60 °C | conc. | + | 11 ± 1 *** | 6/500 |
| Water S | PET | RS (water) | 10 days, 60 °C | conc. | + | 12 ± 3 ** | 6/500 |
| Water G | PET | RS (water) | 10 days, 60 °C | conc. | + | 12 ± 2 ** | 6/500 |
| Water T | PET | RS (water) | 10 days, 60 °C | conc. | + | 18 ± 4 ** | 9/500 |
| Water N | PET | RS (water) | 10 days, 60 °C | conc. | + | 14 ± 2 ** | 7/500 |
S: simulant (formulation simulant); FS: food simulant; RS: real sample (the original content of the container); conc.: concentration of the extract; non conc.: extract that was not concentrated; LLE: liquid-liquid extraction; LDPE: low-density polyethylene; PP: polypropylene; PE: polyethylene; PET: polyethylene terephthalate; EtOH10: 10% ethanol(aq); EtOH50: 50% ethanol(aq); AC3: 3% acetic acid(aq); MeOH: methanol; m/z: mass-to-charge ratio; -: not detected; +: detected; /: estimation of oleamide intake was not calculated; either it was not possible (concentration of oleamide < LOQ) or the extraction solvent did not simulate the real container content; <LOQ: below the limit of quantification; A–T: labels representing different brands per tested material; d: days; h: hours.