Biomaterial Database

Determination of acidic herbicides using liquid chromatography with pneumatically assisted electrospray ionization mass spectrometric and tandem mass spectrometric detection. 1998

B Køppen, and N H Spliid

National Environmental Research Institute, Department of Environmental Chemistry, Roskilde, Denmark.

Liquid chromatography-pneumatically assisted electrospray mass spectrometry with negative ionization has been used for the determination of acidic herbicides in ground water. Eighteen pesticides or pesticide degradation products belonging to several different groups of acidic herbicides (phenoxy acids, sulfonylureas, phenols, etc.) were covered in the study. Optimization of electrospray inlet conditions is described as well as results from investigations of the linearity of the detector response. Conditions for tandem mass spectrometry (MS-MS) detection of characteristic daughter ions formed by collision-induced dissociation (CID) of the parent ion are described and a comparison of obtainable instrument detection limits by single MS and MS-MS was made. Detection limits using MS in the selected ion monitoring (SIM) mode were generally in the order of 1 microgram/l or below, whereas detection limits were three-four times higher using MS-MS detection. A principle of analysis is proposed based on single quadrupole MS as a method for quantitative determination followed by verification of positive findings by CID MS-MS. Application of the method for detecting acidic herbicides residues in a "real-world" ground water sample is demonstrated.

UI	MeSH Term	Description	Entries
D010573	Pesticide Residues	Pesticides or their breakdown products remaining in the environment following their normal use or accidental contamination.	Pesticide Residue,Residue, Pesticide,Residues, Pesticide
D002138	Calibration	Determination, by measurement or comparison with a standard, of the correct value of each scale reading on a meter or other measuring instrument; or determination of the settings of a control device that correspond to particular values of voltage, current, frequency or other output.	Calibrations
D002853	Chromatography, Liquid	Chromatographic techniques in which the mobile phase is a liquid.	Liquid Chromatography
D005618	Fresh Water	Water containing no significant amounts of salts, such as water from RIVERS and LAKES.	Freshwater,Fresh Waters,Freshwaters,Water, Fresh,Waters, Fresh
D006540	Herbicides	Pesticides used to destroy unwanted vegetation, especially various types of weeds, grasses (POACEAE), and woody plants. Some plants develop HERBICIDE RESISTANCE.	Algaecide,Algicide,Herbicide,Algaecides,Algicides
D006863	Hydrogen-Ion Concentration	The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH	pH,Concentration, Hydrogen-Ion,Concentrations, Hydrogen-Ion,Hydrogen Ion Concentration,Hydrogen-Ion Concentrations
D012680	Sensitivity and Specificity	Binary classification measures to assess test results. Sensitivity or recall rate is the proportion of true positives. Specificity is the probability of correctly determining the absence of a condition. (From Last, Dictionary of Epidemiology, 2d ed)	Specificity,Sensitivity,Specificity and Sensitivity
D013058	Mass Spectrometry	An analytical method used in determining the identity of a chemical based on its mass using mass analyzers/mass spectrometers.	Mass Spectroscopy,Spectrometry, Mass,Spectroscopy, Mass,Spectrum Analysis, Mass,Analysis, Mass Spectrum,Mass Spectrum Analysis,Analyses, Mass Spectrum,Mass Spectrum Analyses,Spectrum Analyses, Mass
D013696	Temperature	The property of objects that determines the direction of heat flow when they are placed in direct thermal contact. The temperature is the energy of microscopic motions (vibrational and translational) of the particles of atoms.	Temperatures
D014873	Water Pollutants	Substances or organisms which pollute the water or bodies of water. Use for water pollutants in general or those for which there is no specific heading.	Water Pollutant,Pollutant, Water,Pollutants, Water