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

679186

Sigma-Aldrich

Acetonitrile solution, contains 0.05 % (w/v) ammonium formate, 5 % (v/v) water, 0.1 % (v/v) formic acid, suitable for HPLC

62122

Sigma-Aldrich

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

62118

Supelco

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

183164

Sigma-Aldrich

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

17236

Sigma-Aldrich

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

574732

Sigma-Aldrich

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

574724

Sigma-Aldrich

Acetonitrile solution, contains 0.05 % (v/v) trifluoroacetic acid

576956

Sigma-Aldrich

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

48075

Supelco

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

W263303

Sigma-Aldrich

(R)-(+)-Limonene, ≥93%

00590590

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

1012772

USP

Dehydrated Alcohol, United States Pharmacopeia (USP) Reference Standard

685461

Sigma-Aldrich

Acetonitrile solution, contains 10.0% acetone, 0.05% formic acid, 40.0% 2-propanol

PHR1320

Supelco

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

675415

Sigma-Aldrich

Acetonitrile, HPLC Plus, ≥99.9%, poly-coated bottles

733466

Sigma-Aldrich

Acetonitrile, electronic grade, 99.999% trace metals basis

45983

Supelco

Acetonitrile, analytical standard

50387

Supelco

Acetonitrile, suitable for HPLC, gradient grade, ≥99.9% (GC)

02851

Sigma-Aldrich

Ethanol, for residue analysis

271004

Sigma-Aldrich

Acetonitrile, anhydrous, 99.8%

459836

Sigma-Aldrich

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

437557

Sigma-Aldrich

Acetonitrile, ≥99.5%, ACS reagent

493511

Sigma-Aldrich

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

360457

Sigma-Aldrich

Acetonitrile, ACS reagent, ≥99.5%

1601340

USP

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

02882

Sigma-Aldrich

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

02870

Sigma-Aldrich

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

110086

Sigma-Aldrich

Acetonitrile, ReagentPlus^®, 99%

02857

Sigma-Aldrich

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

PHR1551

Supelco

Acetonitrile, Pharmaceutical Secondary Standard; Certified Reference Material