Simazine water analysis

Supercritical fluid extraction (SFE) is generally used for the extraction of selected analytes from solid sample matrices, but applications have been reported for aqueous samples. In one study, recoveries of 87-100% were obtained for simazine, propazine, and trietazine at the 0.05 ug mL concentration level using methanol-modified CO2 (10%, v/v) to extract the analytes, previously preconcentrated on a C-18 Empore extraction disk. The analysis was performed using LC/UV detection. Freeze-dried water samples were subjected to SFE for atrazine and simazine, and the optimum recoveries were obtained using the mildest conditions studied (50 °C, 20 MPa, and 30 mL of CO2). In some cases when using LEE and LC analysis, co-extracted humic substances created interference for the more polar metabolites when compared with SFE for the preparation of the same water sample. ... 

The first work in this field was probably that of Piletsky et al. [84] that described a competitive FILA for the analysis of triazine using the fluorescent derivative 5-[(4,6-dichlorotriazin-2-yl)amino]fluorescein. The fluorescence of the supernatant after incubation was proportional to the triazine concentration and the assay was selective to triazine over atrazine and simazine. The same fluorescent triazine derivative was applied to competitive assays using atrazine-imprinted films [70]. To this end an oxidative polymerization was performed in the presence of the template, the monomer(s) 3-thiopheneboronic acid (TBA) or mixtures of 3-amino-phenylboronic acid (APBA) and TBA (10 1) in ethanol-water (1 1 v/v) where the template is more soluble. The polymers were grafted onto the surface of polystyrene microplates. The poly-TBA polymers yielded a detection limit of 8 pM atrazine whereas for the poly-TBA-APBA plates it was lowered to 0.7 pM after 5 h of incubation. However, a 10-20% decrease in the polymer affinity was observed after 2 months. 

Huang, S-B., T.J. Mayer, R.A. Yokley, and Rolando Perez (2006). Direct aqueous Injection LC-ESI/MS/MS analysis of water for atrazine, simazine, and their chlorotriazine metabolites. J. Agric. Food Chem., 54(3) 713-719. 

The majority (78%) of the CWS in the 32 states use groundwater as the raw water source (Table 29.2). Thus, the two herbicides databases contain more groundwater (four to five times) than surface water samples (Tables 29.3 and 29.4). The most frequently used limits of quantification (LOQ) for the analysis of atrazine were equal to or less than 0.5ppb (1/6 of MCL) in 28 states, 0.6ppb in one state, and l.Oppb and 2.5ppb in the other two states, respectively. Prior to 1997, two states had an LOQ at the MCL of 3 ppb. The LOQs were lowered in 1997 and subsequent years to less than 1 ppb. The LOQs for simazine were equal to or less than 0.8ppb (—1/5 of MCL) in 27 of the 31 states. LOQs of l.Oppb (1/4 of MCL) and 2.0ppb (1/2 of MCL) were used in the other four states. By 2005, almost all CWS in the United States used LOQs of 0.1 ppb or lower. 

The application of MIPs prepared using triazines as templates to the SPE of water samples requires drying of the cartridge after the sample application in order to remove water traces, which would disrupt the interactions between the analytes and the sorbent. In the protocol described by Matsui et al. [19] the aqueous sample was applied to the MIP cartridge, which was then carefully dried prior to a selective dichloromethane wash (entry D in Tables 15.1 and 15.2). HPLC-UV analysis of wastes and extracts showed that all the impurities were washed off without significant elution of simazine (4) and that the analyte was quantitatively recovered in the eluate. 

Triazines such as atrazine, propazine or simazine, are widely used herbicides. Currently, the determination of atrazine in water and soil samples is mainly done by GLC (1,2) or HPLC (3-5). However, these procedures require cumbersome cleanup steps which could be avoided by using immunoassays as an alternative approach to residue analysis. Such immunochemical determination based on competitive binding of herbicides or pesticides to an antibody (6,7), has been described recently for s-... 

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. 

One of the online inununosensor systems developed in recent years and that has attracted much attention is the prototype FIA River ANALyser (RIANA system), which was developed under the European Commission funding. The RIANA system incorporates a multiple analytes immunoanalysis based on total internal reflection fluorescence with 15 minutes for each analysis [109,110]. The transducer consists of a quartz slide with spatially resolved surface modification for antigen immobilization, along which a coupled laser beam propagates by total internal reflection. The antibodies are labeled with Cy5.5 fluorescent dye, which competes with the free analyte. The system has been applied for the detection of chlorotriazines, atrazine, simazine, and isoproturon. Detection limit for isoproturon in river water was 0.14... 

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