, 271-280 (1999)
High-performance liquid chromatography coupled with mass
spectrometry applied to analyses of pesticides in water. Results
obtained in HPLC/MS/APCI in positive modeR. Jeannot and E. Sauvard
BRGM, Service Minier National, Département Analyse et
Caractérisation Minérale, BP. 6009, 45060 Orléans Cedex 02, France
Determinations of pesticides and their degradation products in natural
waters, given the great heterogeneity of the substances involved,
conventionally demands the use of the following analytical
gas chromatography with different specific detectors such as the
electron capture detector, NPD thermo-ionic detector, and mass spectrometry,
high-performance liquid chromatography combined with a diode array
ultraviolet detector or a spectrofluorimeter after derivatization,
thin-layer chromatography (TLC) with detection of the isolated
substances by UV.
With liquid chromatography, the most widely used detector is the diode-array
UV detector. This method, recommended in French standard AFNOR T 90 123
(EN ISO 11369) , represents a significant advance in the approach to the
identification of polar substances detected in unknown samples, compared
with the results obtained by UV detection with a single wavelength.
However, this method of detection does not guarantee the identification
of the detected substances in absolute terms. Confirmation on a second
column or by gas chromatography is therefore
The atmospheric interfaces equipped with APCI (Atmospheric Pressure Chemical
Ionization) or ESI (Electrospray Ionization) ion sources help to broaden the
field of application of the couplings of liquid chromatography with mass
spectrometry, and have seen substantial developments in recent years [2-4].
They offer performance in agreement with environmental requirements in terms
of quantification limits, sensitivity, simplicity of use and reliability .
They are accordingly suitable for the identification and quantification of
pesticides and their conversion products in waters [6,7].
This article presents a summary of the results obtained on surface waters
with the APCI interface in positive ionization mode, after extraction of
the pesticides at neutral pH. The analyses were performed as part of a
multi-residue approach applied to a priority list of 40 pesticides to be
determined in the surface waters of the Centre region of France.
In addition to high-performance liquid chromatography combined with the
diode array UV detector and coupled with mass spectrometry, gas
chromatography coupled with mass spectrometry was used as a technical
complement, because of its suitability for apolar substances such as
lindane, organochlorinated pesticides, certain organophosphorus pesticides,
For the other substances investigated, such as triazines and some of their
degradation products, phenylureas, triazoles, amides and carbamates,
high-performance liquid chromatography coupled in series with a UV detector
and a mass spectrometer was employed. The results obtained with the diode
array UV detector were compared with those obtained with the mass
spectrometer in order to validate the results obtained with the latter
Acquisition and quantification methods optimized for HPLC/MS with APCI
interface in positive ionization mode are presented in the article.
Results on samples of surface waters with preconcentration following the
liquid/liquid or liquid/solid methods are described. The analytical
approach is set for: preconcentration methods, HPLC/MS acquisition
parameters, quantification methods, practical limits of quantification,
HPLC / mass spectrometry / atmospheric interface / APCI /
pesticides / waters.
© EDP Sciences, Wiley-VCH 1999