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

09-0790

Sigma-Aldrich

Ethanol, JIS special grade, 94.8-95.8%

PHR1070

Supelco

Dehydrated Alcohol, Pharmaceutical Secondary Standard; Certified Reference Material

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

09-0800

Sigma-Aldrich

Ethanol, JIS first grade, 94.8-95.8%

62122

Sigma-Aldrich

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

62118

Supelco

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

183164

Sigma-Aldrich

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

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%

2858

Sigma-Aldrich

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

00590590

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

17236

Sigma-Aldrich

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

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

01-0623

Sigma-Aldrich

Acetonitrile, for residue analysis, JIS 5000

01-0645

Sigma-Aldrich

Acetonitrile, for chromatography

01-0590

Sigma-Aldrich

Acetonitrile, JIS special grade, ≥99.5%

09-0852

Sigma-Aldrich

Ethanol, ≥99.5%

01-0620

Sigma-Aldrich

Acetonitrile, ≥99.8%, for residue analysis, JIS 300

01-0600

Sigma-Aldrich

Acetonitrile, SAJ first grade, ≥99.0%

01-0622

Sigma-Aldrich

Acetonitrile, ≥99.8%, for residue analysis, JIS 1000

09-0760

Sigma-Aldrich

Ethanol, ≥99.5%, SAJ super special grade

01-0650

Sigma-Aldrich

Acetonitrile, ≥99.8%, suitable for HPLC

09-0851

Sigma-Aldrich

Ethanol, ≥99.5%, suitable for HPLC

09-0830

Sigma-Aldrich

Ethanol, JIS 300, ≥99.5%, for residue analysis