Photo-induced chemiluminescence-based determination of diphenamid by using a multicommuted flow system.
Talanta
; 73(4): 718-25, 2007 Oct 15.
Article
in En
| MEDLINE
| ID: mdl-19073093
ABSTRACT
This manuscript deals with the application of molecular connectivity calculations to predict the photo-induced chemiluminescent behaviour of the family of herbicides grouped as amides. Several compounds of this group were theoretically studied by means of a general discriminant equation formerly obtained, being 18 of them (plus eight from the chloroacetanilide sub-group) predicted with a high probability as photo-induced chemiluminescent. Empirical confirmation of the chemiluminometric behaviour was performed with some few commercially available amide herbicides. On the basis of these results, a new multicommutation-photo-chemiluminescent method is proposed for the determination of the diphenamid. The method is based on the photodegradation of the pesticide and then the resulting photo-fragment solutions are oxidized by K(3)[Fe(CN)(6)] in sodium hydroxide medium, at room temperature and 80 degrees C, for the photodegradation and chemiluminometric oxidation, respectively. The studied calibration up to 5.0mgl(-1), revealed a linear dynamic graph up to 20mgl(-1). The reproducibility between days resulted in a R.S.D. (in slope %) of 2.8 (n=5) and the repeatability with a %R.S.D. (n=20) of 4.3. LOD (s/n=3) of 1mugl(-1) and sample throughput of 20h(-1). The influence of foreign compounds is also tested and the optimized flow assembly is applied to different kind of samples.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Language:
En
Journal:
Talanta
Year:
2007
Document type:
Article
Affiliation country:
Spain