Table 1.
Selected HPLC methods for the determination of phenolic compounds in rice.
| Chromatographic Technique | Stationary Phase | Mobile Phase | Quantitative Analysis | Validation | Samples Origin | Target Analytes | Reference |
|---|---|---|---|---|---|---|---|
| HPLC-DAD | Kinetex C-18 (150 × 4.6 mm, 5 µm) |
A: 0.1% Formic acid in water B: 0.1% Formic acid in acetonitrile C: 0.1% Formic acid in methanol |
y | y | Rice from Brazil | Gallic acid; Protocatechuic acid; 4-Hydroxybenzoic acid; Catechin; Vanillic acid; Caffeic acid; Chlorogenic acid; Syringic acid; Epicatechin; p-Coumaric acid; trans-Ferulic acid; Sinapic acid; Kaempferol-3DGlp; Myricetin; Resveratrol, trans-Cinnamic acid; Quercetin; Kaempferol. | [35] |
| HPLC-DAD | Zorbax SB-CN (150 × 3 mm, 3.5 µm) |
A: 0.2% Phosphoric acid B: Water C: Acetonitrile |
y | n | Kamlaing black rice from Thailand | Caffeic acid; p-Coumaric acid; Ferulic acid; Gallic acid; Protocatechuic acid; Hydroxybenzoic acid; Sinapic acid; Vanillic acid; Syringic acid; Cyanidin-3-glucoside; Cyanidin (aglycone) | [41] |
| 1. HPLC-ESI(+)-MS/MS (qualitative) 2. HPLC-APCI(+)-MS (quantitative) |
Zorbax Eclipse (100 × 3 mm, 3.5 µm) |
A: 0.5% Formic acid B: Methanol |
y | n | Four varieties of black rice from Thailand | Cyanidin 3-glucoside; Peonidin 3-glucoside | [26] |
| 1. HPLC-ESI(−)-MS/MS (qualitative) 2. HPLC-DAD (quantitative) |
Phenolic acids Zorbax Eclipse XDB C18 (150 × 4.6 mm, 5 µm) |
Free phenolic acids A: 2.5% Methanol + 0.5% Formic acid in water B: Methanol Bound phenolic acids A: 50 mM Phosphoric acid at pH 2.5 B: Acetonitrile |
y | n | Non-glutinous purple rice from Thailand | Protocatechuic acid; Vanillic acid; p-Coumaric acid; Ferulic acid; Gallic acid; p-Hydroxybenzoic acid | [23] |
| 1. HPLC-ESI(+)-MS/MS (qualitative) 2. HPLC-DAD (quantitative) |
Anthocyanins Symmetry C18 column (75 × 4.6 mm, 3.5 µm) |
Anthocyanins A: 5% Formic acid in water B: 5% Formic acid in acetonitrile |
y | n | Cyanidin-3-glucoside; Peonidin-3-glucoside | ||
| HPLC-DAD-APCI(+/−)-MS |
Phenolic acids Zorbax SB-Aq (250 × 4.6 mm, 5 µm) |
Phenolic acids A: 2.5% Formic acids in water B: Methanol |
n | n | Eight red-grain and three light brown-grained rice varieties from Sri Lanka | Ferulic acid; p-Coumaric acid; Sinapic acid; Caffeic acid | [10] |
|
Proanthocyanidins Ascentis C18 (250 × 4.6 mm, 5 µm) |
Proanthocyanidins A: 0.3% Formic acid in water B: 0.1% Formic acid in methanol |
n | n | Dimers and trimers | |||
| 1. HPLC-DAD (Phenolic acids) 2. HPLC-DAD-ESI(−)-MS/MS (Identification of unknown peaks) |
1. Phenolic acids Atlantis dC18 (250 × 4.6 mm, 5 µm) 2. Unknown peaks Hydrosphere C18 HS-3C2 (150 × 2.0 mm, 5 µm) |
1. Phenolic acids A: 0.1% Formic acid in water B: Methanol 2. Unknown peaks A: 0.1% Formic acid in water B: 0.1% Formic acid in Methanol |
y | n | Colored rice bran from six rice samples collected from the local markets | Protocatechuic acid; p-Hydroxybenzoic acid; Vanillic acid; p-Coumaric acid; Ferulic acid; Sinapic acid; Protocatechualdehyde. | [42] |
| 3. HPLC-DAD-ESI-MS/MS (Anthocyanins) | YMC-pack ODS-AQ (250 × 4.6 mm, 5 µm) |
A: 0.1% Formic acid in water B: Methanol |
y | n | Cyanidin 3-glucoside; Peonidin 3-glucoside; Cyanidin 3-rutinoside | ||
| HPLC-DAD | Kinetex C18 (150 × 4.6 mm, 2.6 µm) |
A: 1% Acetic acid in water B: 1% Acetic Acid + 32% Acetonitrile in water |
y | n | Four samples of Zizania aquatica L. purchased in local markets in Czech Republic | Chlorogenic acid; Gallic acid; Protocatechuic acid; p-Hydroxybenzoic acid; Vanillic acid; Caffeic acid; Syringic acid; p-Coumaric acid; Ferulic acid; Sinapic acid; Ellagic acid; o-Coumaric acid; Protocatechuic ethyl acid; Cinnamic acid; Epigallocatechin; Catechin; Epicatechin; Rutin; Quercetin; Kaempferol. | [14] |
| HPLC-VWD | Zorbax SB-C18 (250 × 4.6 mm, 5 µm) |
A: 0.4% Acetic acid B: Acetonitrile |
y | n | Fresh brown rice from China | Protocatechuic acid; Chlorogenic acid; Caffeic acid; Syringic acid; Coumaric acid; Ferulic acid. | [39] |
| HPLC-VWD | Zorbax SB-C18 (250 × 4.6 mm, 5 µm) |
A: 0.4% Acetic acid B: Acetonitrile |
y | n | Indica cultivar Yinfengxue and Japonica cultivar Wujingyun 27 from China | Protocatechuic acid; Chlorogenic acid; Caffeic acid; Syringic acid; Coumaric acid; Ferulic acid. | [15] |
| HPLC-DAD | C18 (150 × 4.6 mm, 5 µm) |
A: 0.1% Trifluoracetic acid in water B: 0.1% Trifluoroacetic acid in acetonitrile |
y | n | Rice from Portugal | Gallic acid; Protocatechuic acid; p-Hydroxybenzoic acid; Vanillic acid; Syringic acid; Chlorogenic acid; Caffeic acid; p-Coumaric acid; Sinapic acid; Ferulic acid. Luteolin-7-O-glucoside; Apigenin-7-O-glucoside; Apigenin; Tricin. | [16] |
| HPLC-DAD | LUNA C-18 (250 × 4.6 mm, 5 µm) |
A: 3% Acetic acid in water B: 3% Acetic acid and 25% Acetonitrile in water |
y | n | Paddy-rice samples from Thailand | 4-Hydroxybenzoic acid: Gallic acid; Protocatechuic acid; p-Hydroxybenzoic acid; Vanillic acid; 6-Hydrocinnamic acid: Chlorogenic acid; Caffeic acid; Syringic acid; p-Coumaric acid; Ferulic acid; Sinapic acid. Rutin; Myricetin; Quercetin; Apigenin; Kaempferol | [21] |
| 1. HPLC-DAD (Phenolic acids and anthocyanins) | Zorbax SB-C18 (150 × 4.6 mm, 3.5 µm) |
Phenolic acids A: 0.1% Formic acid in water B: 0.1% Formic acid in Acetonitrile Anthocyanins A: 6% Formic acid in water B: Methanol |
y | n | Six rice cultivars from Texas | Protocatechuic acid; Vanillic acid; p-Coumaric acid; Ferulic acid; Sinapic acid. Cyanidin 3-galactoside; Cyanidin 3-glucoside; Cyanidin 3-rutinoside; Peonidin 3-glucoside. | [36] |
| 2. HPLC-FD (Proanthocyanidins) | Develosil Diol (250 × 4.6 mm, 5 μm) |
A: 2% Acetic acid in acetonitrile B: 2% Acetic acid + 3% water in acetonitrile |
y | n | Monomers to decamers | ||
| 1. HPLC-DAD-ESI(−)-MS/MS (Phenolic acids) 2. HPLC-DAD-ESI (+)-MS/MS (Anthocyanins) | 1. RP 18 (250 × 4.6 mm, 5 µm) 2. Gemini C18 110A (150 × 4.6 mm, 5 µm) |
1. Phenolic acids A: 0.1% Acetic acid in water B: 0.1% Acetic acid in methanol 2. Anthocyanins A: 0.5% Formic acid in water B: 0.5% Formic acid in methanol |
y | n | White, red and black rice from China | Protocatechuic acid; Vanillic acid; p-Hydroxybenzoic acid; Syringic acid; trans-p-Coumaric acid; trans-Sinapic acid; Ferulic acid. Cyanidin 3-glucoside; Peonidin 3-glucoside; Cyanidin 3-rutinoside | [19] |
| HPLC-DAD | Intersil ODS-3 (150 × 4.6 mm, 5 μm) |
A: Trifluoroacetic acid in water (pH 2.5) B: Acetonitrile |
y | n | Various rice varieties from Iran | Gallic acid; Salicylic acid; Caffeic acid; Pyrogallol; Quercetin; Rutin; Myricetin; Kaempferol; Naringin; Apigenin; Genistein; Daidzein | [18] |
| HPLC-DAD | RP 18 LiChroCART (250 × 4 mm, 5 µm) |
A: 2% Acetic acid and 5% Methanol in water B: 2% Acetic acid and 88% Methanol in water |
y | y | Commercial rice samples from Spain | Protocatechuic acid; Vanillin; Protocatechuic aldehyde; p-Hydroxybenzoic acid; p-Hydroxybenzaldehyde; Ferulic acid; Sinapic acid; Guaiacol; p-Coumaric Acid; Caffeic acid; 5-Hydroxymethyl-2-furaldehyde; Furfural; 5-Methylfurfural; Syringic Acid; Ellagic acid | [34] |
| 1. HPLC-DAD-ESI(+/−)-MS/MS (Hydroxycinnamic acids and flavonols) |
Zorbax Eclipse XDB-C18 (150 × 2.1 mm, 3.5 μm) |
A: 3% Acetonitrile and 8.5% Formic acid in water B: 50% Acetonitrile and 8.5% Formic acid in water C: 90% methanol and 8.5% formic acid in water |
y | n | White, red and black cultivars from Italy | 3-p-Coumaroylquinic acid; 3-Feruloylquinic acid; 4-p-Coumaroylquinic acid; 4-Feruloylquinic acid; Quercetin 3-glucoside; Quercetin 3-rutinoside; Isorhamnetin 3-glucoside; Isorhamnetin 3-rutinoside; Quercetin; Isorhamnetin; Diidroquercetin 3-glucoside; Diidroisorhamnetin-3-glucoside. | [27] |
| 2. HPLC-DAD-ESI -MS/MS (Anthocyanins) | A: 3% Acetonitrile and 10% Formic acid in water B: 50% Acetonitrile and 10% Formic acid in water |
Cyanidin 3-glucoside; Peonidin 3-glucoside; Cyanidin 3-gentioside; Cyanidin 3-rutinoside; Malvidin 3-glucoside; Peonidin 3-rutinoside. | |||||
| 3. HPLC-DAD-ESI -MS/MS (Flavan-3-ols) |
A: 1% Formic acid and 2% Methanol in water B: Methanol |
Catechin; Epicatechin; Gallocatechin; Epigallocatechin (monomers and dimers) | |||||
| HPLC-DAD-ESI(+/−)-MS | Zorbax Eclipse plus (150 × 4.6 mm, 5 µm) |
A: Acetonitrile B: 2% Acetic acid in water |
n | n | Black rice from China | Cyanidin 3-sophoroside; Cyanidin 3-glucoside; Peonidin 3-glucoside; Procyanidin glucoside; Caffeic acid hexose; Procyanidin B2-3-O-gallate hexose;Epiafzelchin-epicatechin-O-dimethylgallate. | [49] |