Fast Analysis of Free Amino Acids in Tobacco by HPLC with Fluorescence Detection and Automated Derivatization

Abstract

A fast, simple, and sensitive HPLC method for the determination of free amino acids in tobacco was described. A fully automated sample processor performed precolumn derivatization of both primary and secondary amino acids with o-phthalaldehyde/3-mercaptopropionic acid and 9-fluorenylmethyl chloroformate (FMOC-Cl), respectively. All reactions were fully automated by means of an injector programme and accomplished in 10 min. Sample preparation consisted of a single step of extraction with 0.1 mol/L HCl at ambient temperature (assisted by sonication) in 30 min, followed by filtration of an aliquot and derivatization. By optimization of sample preparation and HPLC conditions, separation of 20 amino acids in 30 min was achieved. Detection limits ranged from 0.50 to 1.40 mg/g; coefficients of variation ranged from 1.8% to 3.9%; recoveries ranged from 84.6% to 108.5%. The method was applied to the analysis of amino acids contents of tobacco leaves in different varieties and flue-curing period.

Analysis and comparison of staminate flowers components in five Chinese walnut varieties

“…Lvling, Zhonglin 1, Liaoning 1, Shangsong 6 and Ma walnut (Jingyi 1) walnut staminate flowers in the blooming period [14] (Table 1), all were collected from the production base of Hebei Green Ridge Co., Ltd. (114°4′ E longitude, 37°3′ N latitude).…”

Free amino acids, biogenic amines, and ammonium profiling in tobacco from different geographical origins using microwave‐assisted extraction followed by ultra high performance liquid chromatography

“…Ninhydrin has been widely used for post‐column derivatization after separation by ion exchange and further UV detection, but throughput and specificity are inadequate and sensitivity is low . Afterwards, the pre‐column derivatization reagents using a separation by RP chromatography were proposed among them, o ‐phthaldialdehyde which does not react with secondary amino groups (e. g. proline, hydroxyproline, and pipecolic acid) ; 9‐fluorenylmethyl‐chloroformate (FMOC‐Cl) with the problem of interferences from the excess FMOC‐Cl and its hydrolysis product (FMOC‐OH) ; phenyl isothiocyanate with the drawback of unstable derivatives, notably aspartic acid and glutamic acid ; 6‐aminoquinolyl‐ N ‐hydroxysuccinimidyl carbamate, whose hydrolysis product interferes in the determination and derivatives decompose easily at room temperature . Diethyl ethoxymethylenemalonate (DEEMM) is a simple, accurate, and sensitive pre‐column derivatization agent, which can allow complete degradation of excess DEEMM with heating.…”

“…Sample preparation is one of the most critical processes for determination of plant metabolites. Several conventional methods, such as vortex, shaking, and ultrasound extraction have been applied to the extraction of amino acids, biogenic amines, and ammonium in plant . However, these conventional extraction techniques are often associated with lower extraction efficiency, poor reproducibility, longer extraction time, and high solvent consumption .…”

Ανάπτυξη Και Αξιολόγηση Νέων Αντιδραστηρίων Παραγωγοποίησης Αμινοξέων Και Αυτοματοποιημένων Διαδικασιών Κατεργασίας Σε Μεθόδους LC-MS / MS

“…Με την ποσοτική ανάλυση των αμινοξέων σε διάφορα βιολογικά υλικά, όπως αίμα και ούρα, καθίσταται δυνατή η κλινική διάγνωση, η πρόληψη και η θεραπεία μεταβολικών ασθενειών κατά τη νεογνική περίοδο, όπως η φαινυλκετονουρία (phenylketonuria, PKU) και η τυροσιναιμία. Παράλληλα, ο ποσοτικός προσδιορισμός τους είναι ιδιαίτερα χρήσιμος στη βιοїατρική έρευνα [1][2][3] , την επιστήμη των τροφίμων [4][5][6] , όπου δύναται να καθοριστεί η ποιότητα των τελικών προїόντων, και σε ιστούς φυτών [7][8][9] .…”