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

48075

Supelco

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

W263303

Sigma-Aldrich

(R)-(+)-Limonene, ≥93%

183164

Sigma-Aldrich

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

17236

Sigma-Aldrich

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

62122

Sigma-Aldrich

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

62118

Supelco

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

2858

Sigma-Aldrich

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

PHR1070

Supelco

Dehydrated Alcohol, Pharmaceutical Secondary Standard; Certified Reference Material

E7148

Sigma-Aldrich

Ethyl alcohol, Pure 190 proof, for molecular biology

PHR1551

Supelco

Acetonitrile(Neat), Pharmaceutical Secondary Standard; Certified Reference Material

00590590

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

PHR1320

Supelco

Residual Solvent - Acetonitrile(solution in DMSO), Pharmaceutical Secondary Standard; Certified Reference Material

40347

Sigma-Aldrich

Ethanol, absolute, semiconductor grade PURANAL^™ (Honeywell 17833), sales not in Germany, ≥99.8% (vol.)

733466

Sigma-Aldrich

Acetonitrile, electronic grade, 99.999% trace metals basis

CN34891

Sigma-Aldrich

Acetonitrile, Preparateur, ≥99.9% (GC), One-time steel-plastic (SP) drum

493538

Sigma-Aldrich

Ethyl alcohol, Pure, 190 proof, meets USP testing specifications

271004

Sigma-Aldrich

Acetonitrile, anhydrous, 99.8%

29221

Sigma-Aldrich

Ethanol, tested according to Ph. Eur.

459836

Sigma-Aldrich

Ethyl alcohol, Pure, 200 proof, anhydrous, ≥99.5%

02483

Supelco

Ethanol, standard for GC

45983

Supelco

Acetonitrile, analytical standard

E2385

Supelco

Ethanol standards 10% (v/v), 10 % (v/v) in H₂O, analytical standard

51976

Sigma-Aldrich

Ethanol, BioUltra, for molecular biology, ≥99.8%, (absolute alcohol, without additive, A15 o¹)

493511

Sigma-Aldrich

Ethyl alcohol, Pure, 190 proof, ACS spectrophotometric grade, 95.0%

34851

Sigma-Aldrich

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

34888

Sigma-Aldrich

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

34881

Sigma-Aldrich

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

439134

Sigma-Aldrich

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

459828

Sigma-Aldrich

Ethyl alcohol, Pure, 200 proof, HPLC/spectrophotometric grade

792780

Sigma-Aldrich

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