Novel Solid-Phase Extraction for Epimer-Specific Quantitation of Ergot Alkaloids in Rye Flour and Wheat Germ Oil

Abstract

Ergot alkaloids and their epimer-specific determination have gained increasing importance for food safety. A solid-phase extraction and cleanup method based on sodium-neutralized strong cation exchange (Na(+)-SCX) was developed to quantitate 12 priority ergot alkaloids in rye flour and wheat germ oil by HPLC fluorescence analysis. Sample preparation is achieved by omitting acidic and alkaline conditions enabling minimized epimerization, which is necessary to determine ergot alkaloids according to their natural distribution in foods. Ergot alkaloids are eluted from SCX-column by forming ion pairs using a sodium hexanesulfonate containing solution which prevents epimerization for at least 96 h. Method validation yielded recoveries of 80-120% (rye flour) and 71-96% (wheat germ oil) with a maximum limit of quantitation (LOQ) of 2.0 μg kg(-1) per ergot alkaloid for both matrices. The applicability of the developed method was demonstrated by analyzing 16 samples from German retail markets: 9 rye flours (max 178 ± 5 μg kg(-1)) and, reported for the first time, 7 wheat germ oils (max 56.8 ± 2.7 μg kg(-1)) expressed as the sum of 12 ergot alkaloids.

A critical analysis of extraction techniques used for botanicals: Trends, priorities, industrial uses and optimization strategies

“…Various techniques are used for clean-up of the alkaloids such as liquid-liquid extraction [117] and solid phase extraction (SPE) or dispersive SPE (dSPE) using various materials and solvents. Mueller et al [118,119] used SPE employing alkaline alumina cartridges, while Mohamed et al [122] used octadecyl (C18) endcapped silica, and Koeppen et al [123] and Malysheva et al [121] employed strong cation exchange (SCX). Recently, Oellig and Schwack [124] developed a fast screening method for the quantification of the total ergot alkaloids in rye using planar SPE.…”

Phytochemicals in whole grain wheat and their health‐promoting effects

“…Ergot alkaloids : Ergot alkaloids are types of indole alkaloids, generated from parasitic fungus infested within cereal grains . Concentration of total ergot alkaloids present in wheat in shipments from 2010 to 2012 averaged 0.23 mg/kg .…”

“…Main alkaloids found in wheat include simple lysergamides ( 178 ) and ergopeptines ( 179–183 ) (Fig. ) . Ergot alkaloids were found to exert toxicities such as hallucinations, convulsions, and vasoconstrictions associated with consumption of ergot‐contaminated grains .…”

Direct preparation of a graphene oxide modified monolith in a glass syringe as a solid-phase extraction cartridge for the extraction of quaternary ammonium alkaloids from Chinese patent medicine

“…Pethidine, atropine, homatropine, cocaine 6.8 × 10 −8 -6.5 × 10 −7 mol/L [6] Poly-(acrylic acid) homopolymerfunctionalized porous zinc sulfide nanospheres HPLC-DAD Berberine, matrine, quercetin, melim - [7] Macroporous Na + -SCX a resin HPLC-DAD Ergot alkaloids 0.2-0.8 μg/kg [8] Silica-based SCX a HPLC-DAD Hyoscyamine, scopolamine 0.25-4 μg/mL [9] Strata SCX a HPLC--MS Pyrrolizidine alkaloids - [10] Alltech "Extract-Clean" SCX a resin HPLC-MS Pyrrolizidine Alkaloids - [11] Bond Elut CBA b HPLC-DAD-FL Opium alkaloids and Opioids 2.5-9.7 ng/mL [12] LiChrolut SCX a HPLC-DAD Pyrrolizidine alkaloids 0.06-0.1 ng/μL [13] Oasis MCX c LC-MS/MS Nicotine, eight nicotine metabolites and two minor tobacco alkaloids 0.25-25 ng/mL (plasma)1.0-25 ng/mL (urine) [14] Oasis MCX c HPLC-DAD Tropane alkaloids 0.13-0.58 ng/μL [15] Oasis MCX c HPLC-DAD Opium alkaloids - [16] a Strong cation exchange. b Weak cation exchange.…”

“…As we know, the sorbent material is the core of SPE, which determines the enrichment, recovery, selectivity, and sensitivity . Recently, silica C18 , cation exchanged absorbents , and mixed‐mode absorbent have been used for extraction of alkaloids in complex samples. Analytical parameters of these sorbents are included in Table .…”