Determination of organic acids in Vaccinium berry standard reference materials

Analytical Chemistry Division, Chemical Science and Technology Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA.
Analytical and Bioanalytical Chemistry (Impact Factor: 3.44). 09/2010; 398(1):425-34. DOI: 10.1007/s00216-010-3916-0
Source: PubMed


Nine organic acids (citric acid, galacturonic acid, glycolic acid, isocitric acid, malic acid, oxalic acid, quinic acid, shikimic acid, and tartaric acid) and two anions (phosphate and sulfate) were determined in a suite of Vaccinium berry-containing dietary supplement standard reference materials (SRMs). Following solvent extraction, three independent methods were utilized in the quantification of these compounds. The first method involved reversed-phase liquid chromatography with ultraviolet absorbance detection at 210 nm and isotope dilution mass spectrometry. The second method utilized ion chromatography with conductivity detection. Finally, gas chromatography with isotope dilution mass spectrometry detection was used following derivatization with N-methyl-N-trifluoroacetamide (MSTFA). The combined data from these methods was used for the assignment of organic acid levels in the seven candidate SRMs.

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    • "Juices were centrifuged for 20 min at 4600Âg (IEC CL) and filtered through 0.45 lm polyvinlydiflouride (PVDF) syringe filters (Restek). Filtrate was placed in 10 mL autosampler vials, sealed with Teflon lined silicon septa (Thermo Fisher Scientific, Waltham, MA) and analyzed on a Dionex HPLC (Sunnyvale, CA) with an AS50 autosampler, a GP50 gradient pump, a LC30 chromatography oven at 30 °C and a PDA100 photo diode array detector collecting absorbance data at 215 nm, controlled by Chromeleon software (Thermo Fisher Scientific, Waltham, MA), using a modified method (Phillips et al., 2010). Twenty microliter juice was injected into an Allure Organic Acids 300 mm HPLC column , also protected by a guard column (Restek). "
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