Anilide analytical methods

Analytical methods for representative anilides are reported in this article. In addition, they are also applicable as multi-residue methods. 

The basic principle of the analytical method for anilides is as follows. Homogenized samples such as fruits and vegetables are extracted with acetone or acetonitrile. In the case of brown rice, samples are added to water and allowed to stand for 2h prior... 

The limit of detection (LOD) is an important criterion of the efficiency of an analytical method. It is characterized by the smallest value of the concentration of a compound in the analytical sample. The detectable amount of anilide compounds is in the range 0.01-0.5 ng by GC and 0.1 ng by HPLC. The limit of quantitation (LOQ) ranges from 0.005 to 0.01 mg kg for vegetables, fruits and crops. The recoveries from untreated plant matrices with fortification levels between 10 and 50 times the LOD and the LOQ are 70-120%. The relative standard deviation (RSD) at 10-50 times the level of the LOD and LOQ are <10 % and <20%, respectively. 

Using multi-analytical methods, most of the anilides, including naproanilide, propanil and mefenacet, show recoveries of >70% from 0.5mgkg fortified tomato. According to the official analytical method of the Ministry of Environment, Japan, the recovery of clomeprop fortified at 0.4mgkg in brown rice is >90% (personal data). 

Immunoassays have been used for the anilide herbicide alachlor, although initial assays were marred by false positives from the sulfonate metabolite in view of its greater water solubility and apparent persistence, a specific ELISA method was developed and used to carry out a widespread screening for both alachlor and the sulfonate metabolite (Thurman et al. 1996). Although sample preparation is considerably less complex than that used for conventional chemical analysis, confirmation of the identity of the analytes is obligatory. 

A chromatographic method for the calculation of the association constants CS-enantiomers, Kur/s, assuming 1 1 complexes, was described by the same authors [60]. Some modifications on the anilide ring of the CS had been introduced to further elucidate the mechanism of enantiorecognition. The studies corroborate the key role of the 7T-7T-interaction between the n-donor group of the CS and the K-acceptor group of the analyte in enantiorecognition. 

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