Ultra-High Performance Liquid Chromatography (UHPLC) Method for the Determination of Limonene in Sweet Orange (Citrus sinensis) Oil: Implications for Limonene Stability.

Ultra-High Performance Liquid Chromatography (UHPLC) Method for the Determination of Limonene in Sweet Orange (Citrus sinensis) Oil: Implications for Limonene Stability.

Journal of AOAC International (2015-04-11)

Matthew W Bernart

ABSTRACT

The citrus-derived bioactive monoterpene limonene is an important industrial commodity and fragrance constituent. An RP isocratic elution C18 ultra-HPLC (UHPLC) method using a superficially porous stationary phase and photodiode array (PDA) detector has been developed for determining the limonene content of sweet orange (Citrus sinensis) oil. The method is fast with a cycle time of 1.2 min, linear, precise, accurate, specific, and stability indicating, and it satisfies U.S. Pharmacopeia suitability parameters. The method may be useful in its present form for limonene processing, or modified for research on more polar compounds of the terpenome. A forced-degradation experiment showed that limonene is degraded by heat in hydro-ethanolic solution. PDA detection facilitates classification of minor components of the essential oil, including β-myrcene.

MATERIALS

Product Number

Brand

Product Description

183164

Sigma-Aldrich

(R)-(+)-Limonene, 97%

W263303

Sigma-Aldrich

(R)-(+)-Limonene, ≥93%

62118

Supelco

(R)-(+)-Limonene, analytical standard

62122

Sigma-Aldrich

(R)-(+)-Limonene, technical, ~90% (sum of enantiomers, GC)

17236

Sigma-Aldrich

3-(Benzyldimethylammonio)propanesulfonate, BioXtra, ≥99.0% (HPCE)

2858

Sigma-Aldrich

Ethanol Fixative 80% v/v, suitable for fixing solution (blood films)

PHR1320

Supelco

Residual Solvent - Acetonitrile, Pharmaceutical Secondary Standard; Certified Reference Material

48075

Supelco

Ethanol solution, certified reference material, 2000 μg/mL in methanol

PHR1070

Supelco

Dehydrated Alcohol, Pharmaceutical Secondary Standard; Certified Reference Material

00590590

(R)-(+)-Limonene, primary reference standard

574732

Sigma-Aldrich

Acetonitrile solution, contains 0.1 % (v/v) trifluoroacetic acid, suitable for HPLC

1012772

USP

Dehydrated Alcohol, United States Pharmacopeia (USP) Reference Standard

02870

Sigma-Aldrich

Ethanol, ACS reagent, prima fine spirit, without additive, F15 o¹

02858

Sigma-Aldrich

Ethanol, purum, absolute ethanol, denaturated with 1% cyclohexane, A15 CYCLO¹, ≥99.8% (based on denaturant-free substance)

02890

Sigma-Aldrich

Ethanol, purum, fine spirit, denaturated with 2% 2-butanone, F25 MEK¹, ~96% (based on denaturant-free substance)

02857

Sigma-Aldrich

Ethanol, purum, fine spirit, denaturated with 4.8% methanol, F25 METHYL¹, ~96% (based on denaturant-free substance)

02882

Sigma-Aldrich

Ethanol, purum, absolute ethanol, denaturated with 2% 2-butanone, A15 MEK¹, ≥99.8% (based on denaturant-free substance)

02856

Sigma-Aldrich

Ethanol, purum, absolute ethanol, denaturated with 4.8% isopropanol, A15 IPA¹, ≥99.8% (based on denaturant-free substance)

792780

Sigma-Aldrich

Ethyl alcohol, Pure, 200 proof, ACS reagent, meets USP testing specifications, Excise Tax-free, Permit for use required

792799

Sigma-Aldrich

Ethyl alcohol, Pure, 190 proof, ACS reagent, meets USP testing specifications, Excise Tax-free, Permit for use required

792802

Sigma-Aldrich

Ethyl alcohol, Pure, 160 proof, Excise Tax-free, Permit for use required

360457

Sigma-Aldrich

Acetonitrile, ACS reagent, ≥99.5%

60004

Sigma-Aldrich

Acetonitrile, ≥99.5% (GC)

494445

Sigma-Aldrich

Acetonitrile, biotech. grade, ≥99.93%

E7023

Sigma-Aldrich

Ethyl alcohol, Pure, 200 proof, for molecular biology

E7148

Sigma-Aldrich

Ethyl alcohol, Pure, 190 proof, for molecular biology

34851

Sigma-Aldrich

Acetonitrile, suitable for HPLC, gradient grade, ≥99.9%

34881

Sigma-Aldrich

Acetonitrile, suitable for HPLC-GC, ≥99.8% (GC)

34888

Sigma-Aldrich

Acetonitrile, for HPLC, for UV, ≥99.9% (GC)

34998

Sigma-Aldrich

Acetonitrile, HPLC Plus, ≥99.9%