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

62122

Sigma-Aldrich

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

PHR1070

Supelco

Dehydrated Alcohol, Pharmaceutical Secondary Standard; Certified Reference Material

183164

Sigma-Aldrich

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

PHR1320

Supelco

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

W263303

Sigma-Aldrich

(R)-(+)-Limonene, ≥93%

E2385

Supelco

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

E7148

Sigma-Aldrich

Ethyl alcohol, Pure 190 proof, for molecular biology

17236

Sigma-Aldrich

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

PHR1551

Supelco

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

2858

Sigma-Aldrich

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

00590590

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

62118

Supelco

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

48075

Supelco

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

40347

Sigma-Aldrich

Ethanol, absolute, sales not in Germany, ≥99.8% (vol.)

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

493511

Sigma-Aldrich

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

29221

Sigma-Aldrich

Ethanol, tested according to Ph. Eur.

459836

Sigma-Aldrich

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

51976

Sigma-Aldrich

Ethanol, BioUltra, Molecular Biology, ≥99.8%, (absolute alcohol, without additive, A15 o¹)

02857

Sigma-Aldrich

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

02483

Supelco

Ethanol, standard for GC

360457

Sigma-Aldrich

Acetonitrile, ACS reagent, ≥99.5%

439134

Sigma-Aldrich

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

34851

Sigma-Aldrich

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

733466

Sigma-Aldrich

Acetonitrile, electronic grade, 99.999% trace metals basis

60004

Sigma-Aldrich

Acetonitrile, ≥99.5% (GC)

110086

Sigma-Aldrich

Acetonitrile, ReagentPlus^®, 99%

271004

Sigma-Aldrich

Acetonitrile, anhydrous, 99.8%

1601340

USP

Residual Solvent Class 2 - Acetonitrile, United States Pharmacopeia (USP) Reference Standard