Spectrofluorimetric Analysis of the Fungicide Carbendazim and Its Metabolite 2-Aminobenzimidazole in Natural Water

A spectrofluorimetric method for the direct analysis of carbendazim [methyl 2-benzimidazole carbamate (MBC)] fungicide and its metabolite 2-aminobenzimidazole (2-AB) in natural waters is described. Very low limit of detection (LOD) and limit of quantification (LOQ) values of 0.002 - 0.06 ng/mL and 0.006 - 0.2 ng/mL, respectively, were determined by spectrofluorimetric method with small relative standard deviation (RSD) values < 1%. This spectrofluorimetric method was applied to the determination of MBC and 2-AB residues in natural waters, with satisfactory recovery values of (88.5% - 119.2%).

PM_(2.5) source apportionment in a French urban coastal site under steelworks emission influences using constrained non-negative matrix factorization receptor model

The constrained weighted-non-negative matrix factorization（CW-NMF） hybrid receptor model was applied to study the influence of steelmaking activities on PM_（2.5）（particulate matter with equivalent aerodynamic diameter less than 2.5 μm） composition in Dunkerque,Northern France. Semi-diurnal PM_（2.5）samples were collected using a high volume sampler in winter 2010 and spring 2011 and were analyzed for trace metals, water-soluble ions, and total carbon using inductively coupled plasma – atomic emission spectrometry（ICP-AES）,ICP- mass spectrometry（ICP-MS）, ionic chromatography and micro elemental carbon analyzer. The elemental composition shows that NO_3^-, SO_4^（2-）, NH_4~＋and total carbon are the main PM_（2.5）constituents. Trace metals data were interpreted using concentration roses and both influences of integrated steelworks and electric steel plant were evidenced. The distinction between the two sources is made possible by the use Zn/Fe and Zn/Mn diagnostic ratios. Moreover Rb/Cr, Pb/Cr and Cu/Cd combination ratio are proposed to distinguish the ISW-sintering stack from the ISW-fugitive emissions. The a priori knowledge on the influencing source was introduced in the CW-NMF to guide the calculation. Eleven source profiles with various contributions were identified： 8 are characteristics of coastal urban background site profiles and 3 are related to the steelmaking activities. Between them,secondary nitrates, secondary sulfates and combustion profiles give the highest contributions and account for 93% of the PM_（2.5）concentration. The steelwork facilities contribute in about 2%of the total PM_（2.5）concentration and appear to be the main source of Cr, Cu, Fe, Mn, Zn.