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

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)

PHR1070

Supelco

Dehydrated Alcohol, Pharmaceutical Secondary Standard; Certified Reference Material

183164

Sigma-Aldrich

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

00590590

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

24106

Sigma-Aldrich

Ethanol, puriss., meets analytical specification of Ph. Eur., BP, 96 % (v/v)

E7148

Sigma-Aldrich

Ethyl alcohol, Pure 190 proof, for molecular biology

PHR1551

Supelco

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

PHR1320

Supelco

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

733466

Sigma-Aldrich

Acetonitrile, electronic grade, 99.999% trace metals basis

51976

Sigma-Aldrich

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

792799

Sigma-Aldrich

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

494445

Sigma-Aldrich

Acetonitrile, biotech. grade, ≥99.93%

60004

Sigma-Aldrich

Acetonitrile, ≥99.5% (GC)

360457

Sigma-Aldrich

Acetonitrile, ACS reagent, ≥99.5%

E7023

Sigma-Aldrich

Ethyl alcohol, Pure 200 proof, for molecular biology

34442

Sigma-Aldrich

Acetonitrile, suitable for DNA synthesis, ≥99.9% (GC)

459828

Sigma-Aldrich

Ethyl alcohol, Pure, 200 proof

32205

Sigma-Aldrich

Ethanol, absolute, reag. ISO, reag. Ph. Eur., ≥99.8% (GC), liquid (clear, colorless)

32221

Sigma-Aldrich

Ethanol, puriss. p.a., absolute, ≥99.8% (GC)

459844

Sigma-Aldrich

Ethyl alcohol, Pure, 200 proof, ACS reagent, ≥99.5%

493546

Sigma-Aldrich

Ethyl alcohol, Pure, 200 proof, meets USP testing specifications

33019

Sigma-Aldrich

Acetonitrile, puriss. p.a., ACS reagent, reag. Ph. Eur., ≥99.5% (GC)

34888

Sigma-Aldrich

Acetonitrile, ≥99.9% (GC)

34851

Sigma-Aldrich

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

34998

Sigma-Aldrich

Acetonitrile, HPLC Plus, ≥99.9%

439134

Sigma-Aldrich

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

02858

Sigma-Aldrich

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