Anyone who has ever sprayed a pesticide will immediately recognize the tight feeling you get in your throat, the burning in your nose, and the watery eyes. These symptoms should be the second clue that what you spraying is not good for you. The first, of course, is that you’re spraying it to KILL things.

In this study, a new design for electrospray ionization ion mobility spectrometry (ESI-IMS) was developed. This design has two important differences in comparison to the present ESI-IMS systems. First, a few centimeters of the cell comprising the electrospray needle was located outside of the oven used for heating the IMS cell. This modification prevents prespray solvent evaporation problems such as needle clogging and disturbance of the electrospray process. Second, in addition to the drift gas, a counterflow of a heated gas (desolvation gas) was used between the counter electrode and the ion gate to speed up the desolvation process (Hill, H. H., Jr. Anal. Chem. 1998, 70, 4929-4938). This modification increased the solvent evaporation and resulted in decreasing the drift time, increasing the peak intensity and increasing the resolving power (RP) or enhancing the resolution for separation of two adjacent ion peaks. In this work, the ion mobility spectra of different compounds including ethion, malathion, metalaxyl, fenamifos, methylamine, triethylamine, tributhylamine, codeine, and morphine were obtained to confirm enhancing of the resolving power of the ion peaks by using the desolvation gas. Furthermore, the method has also been applied to obtain the figures of merit for ethion as a test compound. The linear dynamic range for ethion was in the range 50-1000 g/L with a limit of quantification of the 50 g/L.

Positive ion mobility spectra of different pesticides, such as sevin or carbaryl (1‐napthyl methylcarbamate), amitraz (N,N′‐[(methylimino) dimethylidyne]di‐2,4‐xylidine), and metalaxyl (methyl‐N‐(2,6‐dimethylphenyl)‐N‐(2‐xylyl)‐DL‐alaninate) as carbamate, amidine, and alkaline groups, respectively, have been studied in air at ambient pressure using ion mobility spectrometry method with 63 Ni ionization source. The limits of detection (LODs) were 5.3×10 −10 , 5.8×10 −10 , and 4.5×10 −10 g for sevin, amitraz, and metalaxyl, respectively. The working range of these compounds was about three orders of magnitude and the relative standard deviation (RSD) of repeatability at the 5 µg mL −1 level were all below 14%. Furthermore, in this study, the influences of IMS cell temperature on the ion mobility spectra of these compounds were investigated.

Abstract Positive ion mobility spectra of different organophosphorus pesticides such as malathion (s-(1,2-dicarb-ethoxyethyl) o,o-dimethyl dithiophosphate), ethion (o,o,o′,o′-tetraethyl s,s′-methylene bis(phosphorodithioate)) and dichlorovos (2,2-dichlorovinyl dimethyl phosphate) have been studied in air at ambient pressure using ion mobility spectrometry method with 63Ni ionization source. The limits of quantification (LOQs) were 1.0 × 10−9, 1.0 × 10−9 and 5.0 × 10−9 g for malathion, ethion and dichlorovos, respectively. The working range of these compounds was about three orders of magnitude and the relative standard deviation (R.S.D.) of repeatability at the 5 μg ml−1 level were all below 15%. Furthermore, in this study, the influences of IMS cell temperature on the ion mobility spectra of these compounds were investigated. Keywords: Malathion; Ethion; Dichlorovos; Ion mobility spectrometry

There have been a lot of apocalyptic buzzwords floating around the web-o-sphere these days. Terms like global warming, bird flu, and weapons of mass destruction are enough to make any one cringe.But there is a very common cause, of environmental problems, that is destroying our planet...