Simazine solid phase extraction

Figure 13.15 Chromatograms obtained by on-line ti ace enrichment of 50 ml of Ebro river water with and without the addition of different volumes of 10% Na2S03 solution for every 100 ml of sample (a) blank with the addition of 1000 p.1 of sulfite (b) spiked with 4 p.g 1 of the analytes and 1000 p.1 of sulfite (c) spiked with 4 p.g 1 of the analytes and 500 p.1 of sulfite (d) spiked with 4 p.g 1 of the analytes without sulfite. Peak identification is as follows 1, oxamyl 2, methomyl 3, phenol 4, 4-niti ophenol 5, 2,4-dinitrophenol 6, 2-chlorophenol 7, bentazone 8, simazine 9, MCPA 10, atrazine. Reprinted from Journal of Chromatography, A 803, N. Masque et ai, New chemically modified polymeric resin for solid-phase extraction of pesticides and phenolic compounds from water , pp. 147-155, copyright 1998, with permission from Elsevier Science.

Figure 13.19 Chromatograms obtained by on-line SPE-GC-MS(SIM) of (a) 10 ml of tap water spiked with pesticides at levels of 0.1 ng 1 1 (b) 10 ml of a sample of unspiked tap water. Peak identification for (a) is as follows 1, molinate 2, a-HCH 3, dimethoate 4, simazine 5, atrazine 6, y-HCH 7, 8-HCH 8, heptachlor 9, ametryn 10. prometryn 11, fen-itrothion 12, aldrin 13, malathion 14, endo-heptachlor 15, a-endosulfan 16, tetrachlor-vinphos 17, dieldrin. Reprinted from Journal of Chromatography, A 818, E. Pocurull et al., On-line coupling of solid-phase extraction to gas chromatography with mass spectrometric detection to determine pesticides in water , pp. 85-93, copyright 1998, with permission from Elsevier Science.

Nash, R.G (1990). Solid-phase extraction of carbofuran, atrazine, simazine, alachlor, and cyanazine from shallow well water. J. Assoc. Off. Anal. Chem., 13 438 142. 

Zahradnickova, H., P. Simek, P. Horicova, and J. Triska (1994). Determination of atrazine and simazine in drinking and surface waters by solid-phase extraction and high performance thin layer chromatography../. Chromatogr. A, 688 383-389. 

Capillary electrophoresis can also be used in a nonaqueous mode, where it is referred to as nonaqueous capillary electrophoresis (NACE). An example from the literature is shown below where the techniques of NACE and HPLC have been compared for the determination of herbicides and metabolites in water samples. The target compounds were simazine (Sz), atrazine (Az), propazine (Pz), ametryn (Am), prometryn (Pm) and three metabolites deisopropylhydroxyatrazine (DIHA), deethylhydroxyatrazine (DEHA) and deethylatrazine (DEA). In both cases, an off-line solid phase extraction (SPE)... 

Trace concentrations of triazines in drinking water may be determined by U.S. EPA Method 525.2, which involves a solid-phase extraction followed by GC/MS analysis. Alternatively, such substances may be detected by GC/NPD following liquid-liquid extraction (U.S. EPA Method 507). Pinto and Jardim (2000) have described a method to measure triazine residues in water. Their method involves concentrating the samples with C-18 solid-phase extraction cartridges followed by HPLC analysis using a C-18 column with UV detection at 230 nm. The method was applied to measure atrazine, simazine, cyanazine, and ametryne in water at a detection level of O.l/irg/L. Zhou et al. (2006) used multiwalled carbon nanotubes as the adsorbents for preconcentration of triazines in water followed by their measurement by HPLC with a diode-array detector. The method was used to analyze atrazine and simazine in environmental waters. The authors have reported detection limits of 33 and 9 ng/L, respectively, for these two compounds under their optimal conditions. 

Atrazine, simazine, terbuthylazine, molinate Solid-phase microwave-assisted extraction using methanol Gas chromatography-mass spectrometry. Limit of detection 1-10 ng/g [382]... 

Some triazines, including atrazine and simazine, were extracted from water by SEE after preconcentration on sohd-phase extraction disks.The freeze-dried residue or SPE disk was then introduced into the extraction cell and eluted with either pure CO2 or methanol or acetone-modified CO2. SEE has been applied in combination with online sohd-phase extraction for pesticides, including triazines. However, this technique is still used mainly on solid matrixes. The main limitation with aqueous matrixes remains the miscibility of water with supercritical carbon dioxide. Recoveries of nonpolar pesticides, extracted by SEE technique using octacedyl-bonded silica, are generally effective with CO2 elution alone. This is not the case for semipolar and polar compounds, such as triazines and their degradation products. For example, the addition of... 

EIA and GC results were compared for the analysis of simazine in soil, using ethyl acetate for extraction of dried samples of sandy loam from a site contaminated by an experimental simazine spill. For 24 samples that had simazine content between 0 and 350 ppb by GC analysis, the results by EIA correlated with r = 0.93 and a slope of 1.26 (Figure 6). For an extended data set of 48 samples containing simazine from 0 to 3 ppm, the correlation between EIA and GC determinations was 0.97, with a slope of 0.81 (A. Lucas, unpublished data). To ensure solubilization of the simazine recovered from the most heavily contaminated samples, methanol was added to the PBS>Tween to 5% (v/v) as coeolvent. Atrazine residues were recovered by extraction with 90% acetonitrile and concentration on SCX solid phase columns. For samples spiked with 10, 25, 50, and 100 ppb (ng atrazine per gram of soil) recoveries of 80%, 82%, 79%, and 93%, respectively, were obtained. 

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