Figure 1
Figure 2
Mass concentrations of pesticide pollutants in river/stream water samples collected in the northwest part of Croatia across application season
| Pesticide compound | March 2015 (N=8) | June 2015 (N=8) | August 2015 (N=7) | ||||||
|---|---|---|---|---|---|---|---|---|---|
| γ (ng/L) | γ (ng/L) | γ (ng/L) | |||||||
| n | Rangea | Medianb | n | Rangea | Medianb | n | Rangea | Medianb | |
| Mesotrione | 0 | 3 | 36–107 | 0 | 0 | ||||
| Tembotrione | 0 | 7 | 51–216 | 77 | 0 | ||||
| AMBA | 0 | 6 | 54–444 | 74 | 1 | 61 | <LOD | ||
| Terbuthylazine | 3 | 9–13 | <LOD | 8 | 20–419 | 42 | 5 | 10–26 | 13 |
| DET | 1 | 9 | <LOD | 4 | 38–200 | 19 | 2 | 14–45 | <LOD |
| Atrazine | 5 | 10–16 | 11 | 5 | 12–34 | 13 | 5 | 9–24 | 14 |
| DIA | 5 | 5–32 | 6 | 6 | 17–123 | 28 | 2 | 19–24 | <LOD |
| DEA | 4 | 8–11 | 4 | 7 | 7–24 | 11 | 5 | 6–32 | 10 |
| Isoproturon | 1 | 146 | <LOD | 0 | 0 | ||||
| Diuron | 0 | 2 | 22–30 | <LOD | 0 | ||||
| Acetochlor | 0 | 1 | 28 | <LOD | 0 | ||||
| Metolachlor | 7 | 9–11 | 9 | 8 | 11–3015 | 147 | 6 | 10–63 | 11 |
| Chlorpyrifos-methyl | 0 | 1 | 26 | <LOD | 0 | ||||
| Chlorpyrifos-methyl-oxon | 1 | 21 | <LOD | 8 | 23–145 | 64 | 3 | 34–198 | <LOD |
| Imidacloprid | 1 | 73 | <LOD | 8 | 12 – 34 | 26 | 0 | ||
Methods for determination of pesticides and their degradation products in natural waters by SPE and HPLC-UV(DAD) or GC-MS(ITD) analysis
| Method of analysis | HPLC-UV(DAD) | GC-MS(ITD) | |||
|---|---|---|---|---|---|
| Method 1 – λ (nm) | Method 2 – λ (nm) | Method 3a – λ (nm) | Method 4a – m/z | Method 5 – m/z | |
| Pesticide | Mesotrione – 220 | Terbuthylazine – 222 | Atrazine – 222 | Trifluralin – 264 | Terbuthylazine – 214 |
| AMBA – 220 | DET – 214 | DEA – 214 | Atrazine – 200 | Chlorpyrifosmethyl – 286 | |
| Tembotrione – 205 | Malathion – 205 | DIA – 214 | Terbuthylazine – 214 | Chlorpyrifosethyl – 314 | |
| Chlorfenvinphos – 205 | Terbuthylazine – 222 | Acetochlor – 223 | Malathion – 173 | ||
| Chlorpyrifos-methyloxon – 205 | DET – 214 | Alachlor – 188 | Chlorfenvinphos – 267 | ||
| Imidacloprid – 270 | Diuron – 210, 245 | Metolachlor – 162 | α-Cypermethrin – 163 | ||
| Linuron – 210, 245 | |||||
| Chlortoluron – 210, 245 | |||||
| Isoproturon – 202, 245 | |||||
| SPE | OASIS HLB | C18 | SDB-1 | C18 | C18 Polar plus/ SDB-1 |
| Activation | MeOH+H2O | ACN+H2O | MeOH+H2O | MeOH+H2O | MeOH+H2O |
| Solvent volume (mL) | 2+2 | 5+5 | 2+5 | 2+5 | 2+5 |
| Sample volume (mL) | 500 | 500 | 500 | 1000 | 500 |
| Eluent | MeOH | ACN+Et.ac | Ac | Et.ac | Et.ac |
| Eluent volume (mL) | 10 | 10+5 | 2 | 2 | 10 |
Number (N) of individual pesticide compounds, their mass concentration range, and the sum of pesticides mass concentrations (Σ) by river/stream across application season
| River/Stream | March 2015 | June 2015 | August 2015 | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| N | γ (ng/L) | N | γ (ng/L) | N | γ (ng/L) | |||||||
| Min | Max | Σ | Min | Max | Σ | Min | Max | Σ | ||||
| Sutla | 3 | 8 | 22 | 41 | 9 | 9 | 2564 | 3455 | 3 | 10 | 63 | 99 |
| Krapina | 7 | 9 | 146 | 219 | 10 | 22 | 3015 | 3992 | 5 | 6 | 198 | 248 |
| Sava 1 | 2 | 9 | 73 | 81 | 11 | 10 | 242 | 947 | 4 | 9 | 45 | 77 |
| Sava 2 | 4 | 6 | 11 | 35 | 11 | 7 | 149 | 498 | – not analysed – | |||
| Drava | 2 | 5 | 10 | 15 | 6 | 22 | 86 | 323 | 2 | 11 | 14 | 25 |
| Plitvica | 2 | 10 | 16 | 25 | 7 | 16 | 115 | 331 | 4 | 10 | 32 | 76 |
| Bistrica | 3 | 9 | 32 | 52 | 10 | 11 | 216 | 582 | 5 | 13 | 61 | 147 |
| Bednja | 5 | 7 | 16 | 56 | 10 | 12 | 444 | 867 | 6 | 11 | 66 | 161 |
Pesticides and pesticide degradation products analysed in this study
| Class/Pesticide | Chemical name | Sa (mg/L) | log Kowa | pKaa |
|---|---|---|---|---|
| Dinitroaniline herbicide | ||||
| Trifluralin | 2,6-dinitro-N,N-dipropyl-4-(trifluoromethyl)aniline | 0.221 | 5.27 | ND |
| s-Triazines and metabolites | ||||
| Atrazine | 6-chloro-N2-ethyl-N4-(1-isopropyl)-1,3,5-triazine-2,4-diamine | 35 | 2.7 | 1.7 |
| Deethylatrazine (DEA) | 6-chloro-N4-isopropyl-1,3,5-triazine-2,4-diamine | 2700 | 1.51 | 1.3b |
| Deisopropylatrazine (DIA) | 6-chloro-N2-ethyl-1,3,5-triazine-2,4-diamine | 980 | 1.15 | 1.2b |
| Terbuthylazine | 6-chloro-N2-tert-buthyl-N4-ethyl-1,3,5-triazine-2,4-diamine | 6.6 | 3.4 | 1.9 |
| Deethylterbuthylazine (DET) | 6-chloro-N2- tert-buthyl -1,3,5-triazine-2,4-diamine | 327.1 | 2.3 | 1.35c |
| Phenylurea herbicides | ||||
| Diuron | 3-(3,4-dichlorophenyl)-1,1-dimethylurea | 35.6 | 2.87 | ND |
| Linuron | 3-(3,4-dichlorophenyl)-1-methoxy-1-methylurea | 63.8 | 3.0 | ND |
| Chlortoluron | 3-(3-chloro-4-methylphenyl)-1,1-dimethylurea | 76 | 2.5 | ND |
| Isoproturon | 3-(4-isopropylphenyl)-1,1-dimethylurea | 70.2 | 2.5 | ND |
| Chloroacetanilide herbicides | ||||
| Acetochlor | 2-chloro-N-(ethoxymethyl)-N-(2-ethyl-6-methylphenyl) acetamide | 282 | 4.14 | ND |
| Alachlor | 2-chloro-N-(2,6-diethylphenyl)-N-(methoxymethyl) acetamide | 240 | 3.09 | 0.62 |
| Metolachlor | (RS)-2-chloro-N-(2-ethyl-6-methyl-phenyl)-N-(1-methoxypropan-2-yl)acetamide | 530 | 3.4 | ND |
| Triketone herbicides and metabolite AMBA | ||||
| Mesotrione | 2-[4-(methylsulfonyl)-2-nitrobenzoyl]cyclohexane-1,3-dione | 1500 | 0.11 | 3.12 |
| 2-Amino-4-(methylsulfonyl) benzoic acid (AMBA) | 2-amino-4-(methylsulfonyl)benzoic acid | NA | 0.38d | 4.24d |
| Tembotrione | 2-[2-chloro-4-methylsulfonyl-3-(2,2,2-trifluoroethoxymethyl) benzoyl]cyclohexane-1,3-dione | 71000 | -1.09 | 3.18 |
| Organophosphorous insecticides and oxo- metabolite | ||||
| Chlorpyrifos-methyl | O,O-dimethyl O-3,5,6-trichloro-2-pyridyl phosphorothioate | 2.74 | 4.00 | ND |
| Chlorpyrifos-ethyl | O,O-diethyl O-3,5,6-trichloropyridin-2-yl phosphorothioate | 1.05 | 4.7 | ND |
| Chlorpyrifos-methyl-oxon | Dimethyl (3,5,6-trichloropyridin-2-yl) phosphate | NA | 1.91e | NA |
| Malathion | Diethyl 2-[(dimethoxyphosphorothioyl)sulfanyl]butanedioate | 148 | 2.75 | ND |
| Chlorfenvinphos | [(EZ)-2-chloro-1-(2,4-dichlorophenyl)ethenyl] diethyl phosphate | 145 | 3.8 | ND |
| Pyrethroid insecticide | ||||
| α-Cypermethrin | Racemate comprising (R) and (S) α-cyano-3-phenoxybenzyl- (1R,3R)-3-(2,2-dichlorovinyl)- 2,2-dimethylcyclopropane- carboxylate | 0.004 | 5.8 | ND |
| Neonicotinoid insecticide | ||||
| Imidacloprid | N-{1-[(6-chloro-3-pyridyl)methyl]-4,5-dihydroimidazol-2-yl}nitramide | 610 | 0.57 | ND |