A novel technique for determination of the fructose, glucose and sucrose distribution in nectar from orchids by HPLC-ELSD

• Published in: Journal of chromatography. B, Analytical technologies in the biomedical and life sciences Vol. 1081-1082; pp. 126 - 130
• Main Authors: Lindqvist, Dan Nybro, Pedersen, Henrik Ærenlund, Rasmussen, Lars Holm
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.04.2018
• Subjects: Chromatography, High Pressure Liquid - methods; Denmark; Fructose - analysis; Glucose - analysis; Limit of Detection; Linear Models; Orchidaceae - chemistry; Plant Nectar - chemistry; Platanthera bifolia (L.) Rich; Platanthera chlorantha (Custer) Rchb; Reproducibility of Results; Sucrose - analysis; Denmark; Platanthera chlorantha (Custer) Rchb; Platanthera bifolia (L.) Rich
• ISSN: 1570-0232; 1873-376X
• DOI: 10.1016/j.jchromb.2018.02.019

The dominant components in floral nectar is fructose, glucose and sucrose. The concentration and the ratio between the sugars are indicative for plant species and play an important part in the interplay between plants and pollinators. In this paper we present a novel HPLC-ELSD based analytical method for sugar characterization of nectar from orchids. Nectar was collected on Whatman No. 1 paper and preserved in the field by 70 v/v% ethanol. The analytical method had a linear range up to at least 3000 mg L−1 for all 3 sugars with a precision of 1.5–1.7%. Correlation coefficients were 0.9999 to 1.0000. The LOD of all sugars were 5–7 mg L−1 and the LOQ were 17–19 mg L−1. Field samples were stable for min. 7 weeks at −18 °C. The technique was applied to two species of Platanthera (Orchidaceae) in order to test whether species-related differences in sugar composition could be observed. No differences were found between the two species, which were sucrose-dominant (53.5–100%) though with high variation within species and between individual flowers. [Display omitted] •Sugar profiling of nectar is an important tool in botany and chemical ecology.•We present a novel HPLC-ELSD method for analysis of sucrose, fructose and glucose in nectar.•The method is robust with appropriate LOD/LOQ.•The technique was applied on two species of closely related orchids to unveil differences in nectar composition.•The orchids did not show any differences in nectar composition.