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)

17236

Sigma-Aldrich

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

183164

Sigma-Aldrich

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

W263303

Sigma-Aldrich

(R)-(+)-Limonene, ≥93%

443611

Sigma-Aldrich

Ethanol, anhydrous, denatured

48075

Supelco

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

62118

Supelco

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

1012772

USP

Dehydrated Alcohol, United States Pharmacopeia (USP) Reference Standard

00590590

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

PHR1320

Supelco

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

24194

Sigma-Aldrich

Ethanol, absolute, denaturated with 0.5-1.5 Vol.% 2-butanone and approx. 0.001% Bitrex (GC), ≥98% (GC)

L010300

Sigma-Aldrich

Ultrapure Acetonitrile

110086

Sigma-Aldrich

Acetonitrile, ReagentPlus^®, 99%

02882

Sigma-Aldrich

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

E7148

Sigma-Aldrich

Ethyl alcohol, Pure, 190 proof, for molecular biology

02856

Sigma-Aldrich

Ethanol, purum, absolute ethanol, denaturated with 4.8% isopropanol, A15 IPA¹, ≥99.8% (based on denaturant-free substance)

02857

Sigma-Aldrich

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

02858

Sigma-Aldrich

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

02890

Sigma-Aldrich

Ethanol, purum, fine spirit, denaturated with 2% 2-butanone, F25 MEK¹, ~96% (based on denaturant-free substance)

02870

Sigma-Aldrich

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

E7023

Sigma-Aldrich

Ethyl alcohol, Pure, 200 proof, for molecular biology

34442

Sigma-Aldrich

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

360457

Sigma-Aldrich

Acetonitrile, ACS reagent, ≥99.5%

459844

Sigma-Aldrich

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

494445

Sigma-Aldrich

Acetonitrile, biotech. grade, ≥99.93%

60004

Sigma-Aldrich

Acetonitrile, ≥99.5% (GC)

PHR1551

Supelco

Acetonitrile, Pharmaceutical Secondary Standard; Certified Reference Material

1601340

USP

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

733466

Sigma-Aldrich

Acetonitrile, electronic grade, 99.999% trace metals basis

45983

Supelco

Acetonitrile, analytical standard