Determination of N-methylcarbamate pesticides in well water by liquid chromatography with post-column fluorescence derivatization

Peak dispersion and hydrolysis kinetics ofN‐methylcarbamates in packed‐bed and coiled capillary reactors

“…If c\ and a 2 are the peak variances just after and just before the T-piece, respectively, it holds a\ = ff f(l + FJFJ 2 (6) Therefore, relatively small reagent flows are preferable. At a sufficiently large linear flow rate the peak variance due to dispersion in a straight open tubular reactor is given by 17…”

“…6 where T is the absolute temperature [K], M e is the molecular weight of the solvent, x e is a parameter equal to 1, 2.6 and 1.9 for non-associated solvents, water and methanol, respectively, n is the solvent viscosity [cP] and V¡ is the molar volume [ml/mol] of the solute at its boiling point. The D m value for aldicarb in methanol + water (45:55 v/v%) at T= 303.2 K is calculated by using the following estimates: M e & 24.3 g/mol, x e ^ 2.28, and f?^0.67cP.…”

HPLC method for the analysis of the urease inhibitor N-(n-butyl)thiophosphoric triamide and its metabolites

“…As such, efforts were initiated to develop a postcolumn system employing hydrolysis coupled with derivatization of the resultant amines. Initial efforts using NaOH to hydrolyze the compounds as described by Hill et al (1984) were unsuccessful. This was attributed to the presence of significant levels of ammonium or other impurities in the NaOH that gave unacceptable background fluorescence.…”

“…As such sensitivity is not adequate to characterize these compounds at typical biological concentrations, efforts were initiated to develop a more sensitive method. This paper describes a postcolumn detection method that was adapted from one described by Hill et al (1984) for analysis of TV-methylcarbamate pesticides. The method reported here is sufficiently sensitive to enable detection of BNPO in soil extracts at concentrations approaching those at which no inhibitory activity is observed.…”

Determination of pesticides in honey using excitation–emission matrix fluorescence coupled with second-order calibration and second-order standard addition methods

“…The fluorescent properties of these pesticides have been widely exploited for analytical purposes [13][14][15]. The method has been exploited in recent years because of its inherent sensitivity.…”