Facile and sensitive spectrophotometric determination of carbosulfan in formulations and environmental samples

Facile, selective and sensitive spectrophotometric method has been developed for the determination of carbosulfan in insecticidal formulations, fortified water, food grains, agriculture wastewater and soil samples with newly synthesized reagents. The method was based on acid and alkaline hydrolysis of the carbosulfan pesticide, and the resultant hydrolysis product of carbosulfan was coupled with 2,6-dibromo-4-methylaniline to give a yellow color product with lambda(max) of 464 nm or interaction with 2,6-dibromo-4-nitroaniline to produce yellow colored product with lambda(max) of 408 nm or coupling with 2,4,6-tribromoaniline to form red colored product has a lambda(max) of 471 nm. Under optimal conditions, Beer's law range for 2,6-dibromo-4-methylaniline (DBMA) was found to be 0.2-12.0 microg ml(-1), 0.6-16.0 microg ml(-1) for 2,6-dibromo-4-nitroaniline (DBNA) and 0.4-15.0 microg ml(-1) for 2,4,6-tribromoaniline (TBA). The molar absorptivity of the color systems were found to be 3.112 x 10(4) l mol(-1) cm(-1) for DBMA, 3.214 x 10(4) l mol(-1) cm(-1) for DBNA and 3.881 x 10(4) l mol(-1) cm(-1) for TBA. Sandell's of the color reactions are 0.013 microg cm(-2) (DBMA), 0.012 microg cm(-2) (DBNA) and 0.011 microg cm(-2) (TBA) respectively. The effect of the non-target species on the determination of carbosulfan was studied to enhance the selectivity of the proposed methods. The formation of colored derivatives with the coupling agents is instantaneous and stable for 28, 30, and 26 h. Performance of the proposed methods were compared statistically in terms Student's F and t-tests with the reported methods.

Development of simple and sensitive spectrophotometric method for the determination of bendiocarb in its formulations and environmental samples

Facile, selective and sensitive spectrophotometric method has been developed for the determination of bendiocarb in its insecticidal formulations, fortified water, food grains, agriculture wastewater and agriculture soil samples with prepared reagents. The method was based on alkaline hydrolysis of the bendiocarb pesticide, and the resultant hydrolysis product of bendiocarb was coupled with 2,6-dibromo-4-methylaniline to give a yellow color product with lambda max of 457 nm or coupling with 2, 6-dibromo-4-nitroaniline to produce a red colored product with lambda max of 474 nm or coupling with 2, 4, 6-tribromoaniline to form orange red colored product has a lambda max of 465 nm. Under optimal conditions, Beer's law range for 2, 6-dibromo-4-methylaniline (DBMA) was found to be 0.6-14.0 microg mL (-1), 0.8-10.0 microg mL (-1) for 2, 6-dibromo-4-nitroaniline (DBNA) and 0.4-10.0 microg mL (-1) for 2, 4, 6-tribromoaniline (TBA). The molar absorptivity of the color systems were found to be 4.126 x 10(4) l mol (-1) cm (-1) for DBMA, 3.254 x 10(4) l mol (-1) cm (-1) for DBNA and 2.812 x 10(4) l mol (-1) cm (-1) for TBA. Sandell's of the color reactions are 0.018 microg cm (-2)(DBMA), 0.052 microg cm (-2)(DBNA) and 0.065 microg cm (-2) (TBA) respectively. The effect of the non-target species on the determination of bendiocarb was studied. The formation of colored derivatives with the coupling agents is instantaneous and stable for 18 h, 30 h, and 12 h. Performance of the proposed methods were compared statistically in terms Student's F and t-tests with the reported methods.

Multiresidue analysis of pesticides in fruits and vegetables by gas chromatography-mass spectrometry

A multiresidue method was assessed for the determination of several pesticides (organochlorine, organophosphorus, pyrethroids, triazole, amidine) using gas chromatography/mass spectrometry. The extraction of pesticides was carried out by liquid-liquid extraction (LLE) and solid-phase extraction (SPE) using two types of columns (CN and C18). The extracts were cleaned by the addition of florisil, the pesticides were separated by capillary column gas chromatography and detected by mass spectrometry in the electron impact mode. The extraction using C18 column provided the best results for most of the analyzed pesticides. The majority of pesticides recoveries from the four fruits and vegetables (apples, pears, tomatoes and pepper) were greater than 60%. Linearity and precision were satisfactory. The estimated limits of detection and limits of quantification ranged from 0.01 to 0.1 mg/kg and from 0.02 to 0.3 mg/kg, respectively. The proposed procedure was found to be useful for the multiresidue analyses of pesticides in agricultural products for routine monitoring programs.