Table 15.
Determination of organic acids and in foods and silage.
| Matrix | Sample Pretreatment, Extraction | Mobile Phase Composition | Measurement Method, Chromatographic Column | Reference |
|---|---|---|---|---|
| Reverse Phase-Based Columns | ||||
| Kombucha | H2O 70–80 °C, filtration | 20 mmol H2PO4− pH 2.4/MeOH (97:3) | Luna C18 250 × 4.6 mm, 5 µm 30 °C UV λ 210 nm | [337] |
| Fresh fruits | Juice extraction, depulping, centrifugation | 50 mmol L−1 H2PO4− pH 2.8 | Hypersil Gold aQ 250 × 4.6 mm, 5 µm 10 °C UV λ 214 nm (254 ascorbic acid) | [338] |
| Medicinal plants infusions | (HPO3)n extraction | 3.6 mmol L−1 H2SO4 | Sphere-Clone C18 250 × 4.6 mm, 5 µm, 35 °C UV λ 215 nm (254 ascorbic acid) | [339] |
| Fruit juices | Filtration | 0.01 mol L−1 KH2PO4 pH 2.6 | RP-C18 150 × 4.6 mm, 3 µm, UV λ 210 nm | [340] |
| Wine | SPE C18 Elution: mobile phase (for acid protonation) |
0.005 mol L−1 H3PO4 pH 2.1, 1 mL/100 mL CAN | Lichrosorb RP-C18 150 × 4.0 mm, 5 µm, UV λ 210 nm | [345] |
| Ion Exchange-Based Columns | ||||
| Sulfite pulp mill | Filtration | 1. Ultrapure water 79 °C 2. Ultrapure water 68 °C 3. H2SO4 0.005 mol L−1 30 °C 4. H2SO4 0.005 mol L−1 60 °C |
RID for all cases, 1. Aminex HPX-87P Pb2+ 300 × 7.8 mm, 9 µm 2. Transgenomic® CHO-782 Pb2+ 300 × 7.8 mm, 7 µm 3. Bio-rad Aminex HPX-87H 300 × 7.8 mm, 9 µm 4. Shodex SH-1011 H+ 300 × 8.0 mm, 6 µm |
[341] |
| Food samples | Liquid samples: filtration Solid samples: H2O 85 °C |
0.005 mol L−1 H2SO4 35 °C | Hi-Plex H 300 × 8.0 mm, 6 µm, RID | [343] |
| Olive fruits | Maceration in H2O MeOH (75:25) | 0.1 g/100 mL H3PO4 | Shodex RSpak KC-118 300 × 8.0 mm, UV λ 214 nm | [344] |
| Wines | Filtration, SPE strong anion exchange | 0.065 mL/100 mL H3PO4 | Aminex HPX-87H 300 × 7.8 mm, 9 µm, 65 °C, UV λ 210 nm | [346] |
| Fermented shrimp waste | Centrifugation, sonication, filtration | (HPO3)n pH 2.1 | SS Exil ODS 250 × 4.0 mm, 5 µm, UV λ 210 nm | [347] |
| Silage | H2O 100 °C | 6 mmol L−1 HClO4 | Shodex KC 811 300 × 8.0 mm, 7 µm 50 °C, UV λ 210 | [348] |
| Ion Exclusion-Based Analysis | ||||
| Drinks | Filtration, heat-aided degassing | Precondition: 10 mmol L−1 SDS 3 h 0.3 mL min−1 Elution: 1.84 mmol L−1 H2SO4 pH 2.43 |
Kinetex XB-C18 150 × 4.6 mm, 2.6 µm, UPLC-UV λ 210 nm | [349] |