The purpose of this research is to develop a direct spectrometric approach to monitor soils and waters, at a lower cost than the widely used chromatographic techniques; a spectrometric approach that ...is effective, reliable, fast, easy to implement, and without any use of organic solvents whose utilization is subject to law limitation. It could be suitable at least as an alert method in case of massive contamination. Here, we present for the first time a catalog of excitation–emission and total synchronous fluorescence maps that may be considered as fingerprints of a series of homologated pesticides, in large use in Morocco, aiming at a direct detection of their remains in agricultural soils and neighboring waters. After a large survey among farmers, agricultural workers and product distributors in two important agricultural regions of Morocco (Doukkala-Abda and Sebou basin), 48 commercial pesticides, which are fluorescent, were chosen. A multi-component spectral database of these targeted commercial pesticides was elaborated. For each pesticide, dissolved in water at the lowest concentration giving a no-noise fluorescence spectrum, the total excitation-emission matrix (TEEM), the total synchronous fluorescence matrix (TSFM) in addition to synchronous fluorescence spectra (SFS) at those offsets giving the highest fluorescence intensity were recorded. To test this preliminary multi-component database, two real soil samples, collected at a wheat field and at a vine field in the region of Doukkala, were analyzed. Remains of the commercial Pirimor (Carbamate) and Atlantis (Sulfonylurea) were identified by comparison of the recorded TEEM, TSFM, and SFS to those of the preliminary catalog at one hand, and on the basis of the results of a field pre-survey. The developed approach seems satisfactory, and the fluorimetric fingerprint database is under extension to a higher number of fluorescent pesticides in common use among the Moroccan agricultural regions.
The k0-method of neutron activation analysis (k0-NAA) was used in order to determine the concentration of major and trace elements in sediment samples collected from different sites in the Gharb ...plain along the Sebou River (Morocco). Samples have been analyzed using neutrons of the Moroccan Triga Mark II research reactor. Two types of irradiation (short and long) have been carried out using the Pneumatic Tube System (PTS) and the Rotary Specimen Rack (RSR). Acquisition and Fitting of spectra have been carried out by Maestro software and k0-IAEA program respectively. Pollution indicators (enrichment factor (EF), geoaccumulation index (Igeo), contamination factor (CF) and pollution load index (PLI)) were calculated to assess the pollution status of the sediments. Results of pollution indices showed no contamination all around the catchment area except for the stations (MS1 and MS2) located downstream the Sebou river. Principal component analysis (PCA) was carried out with the Pearson coefficient in order to determine possible relationships between major and trace elements. The comparison with other subsequent studies on Sebou river gives an idea about the temporal evolution of heavy metal contamination at national scale.
The present study, combining UV–Visible absorption and 3D fluorescence supported by PARAFAC chemometric analysis, focused on the characterization of soil water extractable organic matter (WEOM) in ...the zone of Doukkala located near the Atlantic coast of Morocco. The extracts, in water, of a set of 30 samples covering the four main types of agricultural soils in the region (commonly labeled Tirs, Faid, Hamri and R’mel) were investigated.
E
2
/
E
3
and
E
4
/
E
6
absorbance ratios
,
S
275
-
295
and
S
350
-
400
spectral slopes, along with their ratios
S
R
, as well as the fluorescence
FI
and humification
HIX
indices were calculated and interpreted. In the four soil types, these parameters revealed, on the one hand, organic materials of terrigenous origin with some biological component, and showed, on the other hand, that these materials are in similar stages of humification with an important humic character. In all the soils investigated, 3D fluorescence crossed with PARAFAC chemometrics highlighted the absence of any protein component and revealed the prevalence of the fulvic acids fraction in the organic matter humic material.
The present work relates to the creation/extension of a database of Total Excitation-Emission and Total Synchronous Fluorescence Matrices (TEEMs and TSFMs) along with optimal Synchronous Fluorescence ...Spectra (SFS) to fingerprint pesticides widely used in Morocco. This spectrometric multi-component fingerprinting may permit the direct detection of pesticides persisting in soil or water. The objective of the current investigation is to detect four pesticide remains in agricultural soils by applying the spectrometric fingerprinting results. They are the commercial: i) insecticide Axlera 5G (carbamate), ii) fungicide Orsalis 5% SC (triazole), iii) insecticide Force 0,5 G (pyrethrinoid) and iv) insecticide Proclaim 05 SG (non-assigned). The agricultural plantations monitored are located in the great agricultural Doukkala region at the western Atlantic side of Morocco, where these chemicals are in large sale and use.
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