. . "Supercritical Fluid Extraction of Amino Acids from Birch (Betula pendula Roth) Leaves and their Liquid Chromatographic Determination with Fluorimetric Detection" . "P(GA526/05/0187), Z(MSM6215648902)" . "398353" . . "1615-9306" . "Hrdli\u010Dka, Petr" . . "RIV/62156489:43410/08:00116481!RIV12-GA0-43410___" . "The method for supercritical fluid extraction (SFE) of amino acids was adapted and optimized for a dry leaves matrix. The matrix-dependent SFE method uses a mixture of MeOH:H2O:acetonitrile (10:10:1 v/v) as a modifier (0.5 ml in situ) at 70 \u00B0C and 40 MPa and no HCl is needed as an entrainer. The amino acids were quantified using high-performance liquid chromatography with fluorimetric detection (HPLC/FLD) after gradient elution on Zorbax Eclipse columns (4.6 x 75 mm) with aqueous Na2HPO4 buffer of pH 7.8 and ACN:MeOH:water as a mobile phase. In comparison with Soxhlet extraction, SFE gained higher recovery and selectivity, but it required longer extraction time (90 min) and it was more labor-intensive (clean-up step after the pre-concentration). Both methods should be used separately or as a combo according to the matrix, number of samples and levels of ballast compounds." . "RIV/62156489:43410/08:00116481" . "[26A2360C5C1E]" . . . "Lojkov\u00E1, Lea" . . "Supercritical Fluid Extraction of Amino Acids from Birch (Betula pendula Roth) Leaves and their Liquid Chromatographic Determination with Fluorimetric Detection"@en . "43410" . . . . . "31" . "8" . . . "DE - Spolkov\u00E1 republika N\u011Bmecko" . "Journal of Separation Science" . . . "Buchta, Ivan" . . "6"^^ . "Supercritical Fluid Extraction of Amino Acids from Birch (Betula pendula Roth) Leaves and their Liquid Chromatographic Determination with Fluorimetric Detection"@en . "Supercritical Fluid Extraction of Amino Acids from Birch (Betula pendula Roth) Leaves and their Liquid Chromatographic Determination with Fluorimetric Detection" . "birch leaves; chromatography; amino acids"@en . "The method for supercritical fluid extraction (SFE) of amino acids was adapted and optimized for a dry leaves matrix. The matrix-dependent SFE method uses a mixture of MeOH:H2O:acetonitrile (10:10:1 v/v) as a modifier (0.5 ml in situ) at 70 \u00B0C and 40 MPa and no HCl is needed as an entrainer. The amino acids were quantified using high-performance liquid chromatography with fluorimetric detection (HPLC/FLD) after gradient elution on Zorbax Eclipse columns (4.6 x 75 mm) with aqueous Na2HPO4 buffer of pH 7.8 and ACN:MeOH:water as a mobile phase. In comparison with Soxhlet extraction, SFE gained higher recovery and selectivity, but it required longer extraction time (90 min) and it was more labor-intensive (clean-up step after the pre-concentration). Both methods should be used separately or as a combo according to the matrix, number of samples and levels of ballast compounds."@en . "11"^^ . . . . "6"^^ . . . . "Kub\u00E1\u0148, Vlastimil" . "Kula, Emanuel" . "Klejdus, Bo\u0159ivoj" .