C. Mouvet et al., VALIDATION OF COMMERCIALLY AVAILABLE ELISA MICROTITER PLATES FOR TRIAZINES IN WATER SAMPLES, Analytica chimica acta, 311(3), 1995, pp. 331-339
Comparative trials were carried out on triazine microtiter plate tests
distributed by Millipore, Riedel-de Haen, Transia and CIFEC. Sensitiv
ity and reproducibility were tested with standard solutions of atrazin
e. Cross-reactivity was studied for hydroxyatrazine, deisopropylatrazi
ne, deethylatrazine, simazine, hydroxysimazine, terbutylazine, hydroxy
terbutylazine and deetylterbutylazine. A set of 19 surface-, 16 ground
- and 6 lysimetric plate water samples were also analysed. Liquid chro
matography with diode array detection or gas chromatography with nitro
gen-phosphorus detection were used as validated central techniques for
those natural samples. Laboratory assays developed by GEC-Marconi as
part of a collaborative European Union research project (BIOPTICAS) ha
ve also been assessed. The lowest detectable dose were those of Riedel
and Transia tests, 0.003 and 0.014 mu g/l, respectively. The other te
sts also enable the detection of atrazine below 0.1 mu g/l. All tests
showed inter-assay coefficients of variation (C.V.) below 20%, the Tra
nsia, GEC-Marconi and Riedel tests producing the lowest inter-assay C.
V.s. The mean intra-assay C.V.s were below 7% for all tests, the most
homogeneous results being those of Transia and CIFEC. Except for the G
EC-Marconi test which appeared very specific for atrazine, the most in
terfering triazines were terbutylazine, simazine and deethylatrazine.
For the complete set of 41 water samples, the triazine concentrations
measured by all the immunoassays and the sum of the triazines determin
ed by gas chromatography-liquid chromatography were correlated at the
0.001 level, while for the water samples collected from lysimetric pla
tes, the correlation coefficients were less significant, except for th
e Riedel test whose correlation coefficient remained significant at th
e 0.001 level. The laboratory-based assay from GEC-Marconi, still unde
r development, showed promising characteristics with respect to sensit
ivity and specificity. The Riedel-de Haen test gave the best overall r
esults.