Determination of Imazethapyr Using Capillary Column Flow Injection Liposome Immunoanalysis

Abstract

A sensitive immunoanalysis system was developed for the quantitation of imazethapyr, the active ingredient in PURSUIT herbicide. Imazethapyr [5-ethyl-2-(4-isopropyl-4-methyl-5-oxo-2-imidazolin-2-yl)nicotinic acid] is one of the imidazolinone class of herbicides. The assay was based on sequential competitive binding of imazethapyr and liposomes for a limited number of antibody binding sites. A capillary tube (20 cm × 0.53 mm i.d.) with immobilized antibody was used as the immunoreactor column. Liposomes that entrap fluorescent molecules as the detectable label provide instantaneous, rather than time-dependent, enhancement, common with enzyme immunoassays. In this study, liposomes encapsulated carboxyfluorescein dye and were made antigenic by incorporating in the bilayer a phospholipid that had the analyte conjugated to its polar head group. The calibration curve for imazethapyr in Tris-buffered saline solution had a working range of 0.1−100 ng/mL. In the range between 1 and 100 ng/mL, recoveries from fortified tap and pond water samples ranged from 93 to 114%. Filtration was the only step needed for sample cleanup, and an assay could be performed in <10 min. Keywords: Imazethapyr; FILIA (flow injection liposome immunoanalysis); capillary immunocolumn; immunoassay; herbicide; liposomes

Design of Electrochemically Modified fMWCNT‐pencil Graphite Electrode Decorated with Cu and Ag Nanofilm and its Electrocatalytic Behavior Towards Imazethapyr

“…Imazethapyr are amphoteric, having both carboxylic acid and basic quinoline and pyridine functional groups and chemically described as 5-ethyl-2-(4-isopropyl-4-methyl-5oxo-4,5-dihydro-1H-imidazol-2-yl) nicotinic acid. It is used to control broad-leaved weeds and grasses in soybean, peas and other leguminous crops [28]. The behavior of herbicide is affected by pH and adsorption capability of soil [29].…”

“…The tolerance limit prescribed by FSSAI is 0.1 mg kg À1 in soybean and groundnut [30]. The determination of Imazethapyr by other analytical methods are fewer in literature, some of them are Capillary Column Flow Injection Immunoanalysis [28] and liquid chromatography [31][32]. These technique use large amount of organic solvents, are time consuming and require expensive instrumentation, hence electrochemical techniques are preferred which have cheap instrumentation, excellent reliability, high sensitivity and low detection limit with rapid and simultaneous analysis of several analytes [1,7,[11][12][13][14]33].…”

Immunoaffinity Chromatography: An Introduction to Applications and Recent Developments

“…This feature allows for improved reproducibility, a wider range of detection formats and lower background signals. Several applications of sequential injection immunoassay applications can be seen in TABLE 3 [134–144]. The sequential injection format tends to give lower LOD than the simultaneous format, because the analyte has a better chance of binding to the column in this format.…”

Ανάπτυξη Μεθόδου Ταυτόχρονου Ανοσοχημικού Προσδιορισμού Καρδιακών Δεικτών Με Τη Χρήση Τριχοειδούς Οπτικού Ανοσοαισθητήρα

“…[200,201,83]. Οι μικρές διαστάσεις του τριχοειδούς επίσης, συντελούν στη μείωση της κατανάλωσης των αντιδραστηρίων και κατά συνέπεια στη μείωση του κόστους της ανάλυσης ενώ διευκολύνουν την κατασκευή φορητών διατάξεων για αναλύσεις πεδίου [202]. Επιπλέον των πλεονεκτημάτων αυτών, το τριχοειδές παρέχει δυνατότητα ροής των αντιδραστηρίων και συνεπώς δύναται να αξιοποιηθεί στην αυτοματοποίηση του προσδιορισμού και συνεπώς σε σύγκριση με τις οπτικές ίνες εμφανίζει μεγαλύτερη εφαρμοσιμότητα στην κατασκευή ανοσοαισθητήρων συνεχούς ροής [203].…”

“…Στους τριχοειδείς ανοσοπροσδιορισμούς και ανοσοαισθητήρες, η σιλανοποίηση πραγματοποιείται στατικά [200,202,208,209,218,231,232,234,238,249], υπό ανάδευση [244,247] ή υπό ροή [215,224,235,240,260] με διαλύματα υγρής φάσης ή κολλοειδούς πηκτής [240,244] [202,208,215,231,235,238]. Συνεπώς αυξάνεται ο χρόνος…”