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PubMed2005

Determination of chloro-s-triazines including didealkylatrazine using solid-phase extraction coupled with gas chromatography-mass spectrometry.

Chloro-s-triazines are a class of compounds comprising atrazine, simazine, propazine, cyanazine and their chlorinated metabolites. The US Environmental Protection Agency (EPA) has determined that selected chloro-s-triazines--atrazine, simazine, propazine, deethylatrazine, deisopropylatrazine, and didealkylatrazine--have a common mode of toxicity related to endocrine disruption. In this paper, a dual-resin solid-phase extraction (SPE) gas chromatography-mass spectrometry (GC-MS) method is reported that provides for each of these chloro-s-triazines including the polar metabolite, didealkylatrazine. The method utilizes deuterated internal standards for quantitation and terbuthylazine as a recovery standard. The limit-of-detection was 0.01 microg/L for simazine, deethylatrazine, deisopropylatrazine and didealkylatrazine, and 0.02 microg/L for atrazine and propazine in surface water. Mean recoveries for 0.5 and 3.0 microg/L spikes for atrazine, simazine, propazine, deethylatrazine, deisopropylatrazine and didealkylatrazine were 94, 104, 103, 110, 108 and 102%, respectively, in surface water. The method was also validated by matrix spikes into fourteen different raw and treated natural surface waters. This method is useful for monitoring "total chloro-s-triazines" in both raw and treated drinking waters.

Gas Chromatography-Mass Spectrometry↗

PubMed2006

Determination of N-nitroso derivatives of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) in soils by pressurized liquid extraction and liquid chromatography-electrospray ionization mass spectrometry.

To aid in the evaluation of the potential toxicity of N-nitroso derivatives of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), we describe a pressurized liquid extraction (PLE) followed by liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS) method for determination of RDX and its N-nitroso derivatives: hexahydro-1-nitroso-3,5-dinitro-1,3,5-triazine (MNX), hexahydro-1,3-dinitroso-5-nitro-1,3,5-triazine (DNX), and hexahydro-1,3,5-trinitroso-1,3,5-triazine (TNX) in soils. Sandy loam soil was spiked with RDX and its N-nitroso derivatives (MNX, DNX, and TNX). Acetonitrile was used as the PLE extraction solvent at 100 degrees C and 1500 psi for 15 min. Florisil was used to cleanup extracts following PLE. Instrumental analysis employed LC-ESI-MS, in which 1mM acetic acid was added to the mobile phase to facilitate formation of acetate adduct ions [M+CH(3)COO](-). The method detection limits (MDLs) for RDX, MNX, DNX, and TNX were 1.46, 1.46, 1.69, and 1.93 ng/g, respectively. High recovery (91.1-108.3%), good precision (RSD: 3.2-12.4%), and reproducibility were achieved. This method proved effective and was applied to monitor the reductive biotransformation of MNX in soils with the presence of earthworms (Eisenia fetida).

Chromatography, High Pressure Liquid↗

PubMed2005

Synthesis, structure and anticancer activity of novel 2,4-diamino-1,3,5-triazine derivatives.

A series of 2-(4,6-diamino-1,3,5-triazin-2-yl)-2-{[4-(dimethylamino)-phenyl]imino}acetonitriles 19-27 have been synthesized by the reaction of 2-(4-amino-6-alkylamino-1,3,5-triazin-2-yl)acetonitriles 10-15 with p-nitrosodimethylaniline. Unexpectedly, a similar reaction of acetonitriles 10, 14, 15, 17 and 18 with nitrosobenzene led to the formation of 4,6-diamino-N-phenyl-1,3,5-triazine-2-carboxamides 28-32. The in vitro antitumor activity of the compounds obtained has been tested and 2-[4-Amino-6-(4-phenylpiperazin-1-yl)-1,3,5-triazin-2-yl]-2{[4-(dimethylamino)phenyl]imino}acetonitrile (19) having remarkable activity against melanoma MALME-3 M cell line (GI(50)=3.3 x 10(-8) M, TGI=1.1 x 10(-6) M) is a leading candidate for further development.

Antineoplastic Agents↗

PubMed2005

Use of pressurized liquid extraction (PLE)/gas chromatography-electron capture detection (GC-ECD) for the determination of biodegradation intermediates of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) in soils.

A rapid, sensitive, and reproducible method was developed for quantitative determination of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) and its biodegradation intermediates, hexahydro-1-nitroso-3,5-dinitro-1,3,5-triazine (MNX), hexahydro-1,3-dinitroso-5-nitro-1,3,5-triazine (DNX), and hexahydro-1,3,5-trinitroso-1,3,5-triazine (TNX) in soils. RDX, MNX, DNX, or TNX was extracted from soil by pressurized liquid extraction (PLE), followed by cleanup using florisil. Instrumental analysis was performed using gas chromatography with electron capture detection (GC-ECD), which was highly sensitive to the parent explosive and its metabolites. The method detection limits (MDLs) were 0.243, 0.095, 0.138, and 0.057 ng/g for RDX, MNX, DNX, and TNX, respectively. The method gave high recovery (98-102%), good precision (0.22-5.14%), and reproducibility, and proved to be suitable for real world sample analysis.

Acetonitriles↗

PubMed2000

Capillary zone electrophoretic separation of neutral species of chloro-s-triazines in the presence of cationic surfactant monomers.

Chloro-s-triazines are difficult to separate by capillary zone electrophoresis (CZE), due to their low pKa values. However, these analytes can be effectively separated by CZE in the presence of cationic surfactant monomers, such as tetradecylammonium bromide (TTAB) and dodecyltrimethylammonium bromide (DTAB). The separation mechanism based on a 1:1 binding of analytes to cationic surfactant monomers is proposed. The binding constants of chloro-s-triazines to cationic surfactant monomers are estimated. The results show that the strength of the interactions of these analytes with TTAB monomers is considerably strong, whereas that of the corresponding analyte with DTAB monomers is about 12- to 14-fold weaker. A linear correlation of binding constants with log P(ow) (the logarithm of the partition coefficient of analytes between 1-octanol and aqueous phases) indicates that the migration order of these chloro-s-triazines depends primarily on their hydrophobicity. Moreover, the skewed peaks of chloro-s-triazines observed may reveal the occurrence of adsolubilization of these analytes in the adsorbed cationic surfactant layer on the capillary surface.

Cations↗

PubMed1979

Protein purification using immobilised triazine dyes.

This review attempts to identify proteins which selectively interact with immobilised triazine dyes such as Cibacron blue F3GA and Procion red HE 3B. Different support matrices are compared by examining the capacities of these dyes for proteins. Various approaches to the immobilisation of triazine dyes are considered together with the use of spacers. Some theories of the mechanism of protein retardation by immobilised dyes are discussed. A number of methods are suggested for the measurement of dye concentrations and for the modification of the binding of proteins to dye columns. The variety of elution methods is compared with a view to optimizing purifications. The scope of applications is reviewed as well as the choice of dye. Some advantages of triazine dyes over other affinity ligands are given. It is concluded that although no satisfactory mechanism for the binding of triazine dyes to proteins has yet been proposed, these dyes possess considerable potential for protein purification, particularly when applied on the large scale.

Animals↗

PubMed1978

Gas-liquid chromatography of triazine herbicides as heptafluorobutyryl derivatives and some applications to analysis in foods.

The heptafluorobutyryl (HFB) derivatives of ten triazine herbicides were prepared by reacting the pesticides with heptafluorobutyric anhydride in benzene, in the presence of trimethylamine or pyridine as catalyst. The reactions produced mainly the mono-HFB products while some of the herbicides had small quantities of the di-HFB derivatives present. The derivatives were 300 fold to several thousand fold more sensitive to electron-capture detection than the underivatized triazines. They also were 5-10 fold more sensitive than the parents by electrolytic conductivity detection in the halogen mode while they were of similar sensitivity with the same detector in the nitrogen mode. The derivatives eluted in the same general order as the parent triazines on stationary phases of OV-1, OV-101, OV-101/QF-1, and OV-210. This method was successfully applied to the analysis of potatoes, peas and tomatoes spiked with various triazines at levels of 0.13-0.86 ppm.

Chromatography, Gas↗

PubMed1977

Capillary gas chromatography of s-triazines.

In order to achieve better resolution and lower detection limits for s-triazines, glass capillary columns made of soft soda-lime glass and etched with gaseous hydrogen chloride have been introduced. Columns with non-polar (OV-101, SE-30) mixed (Carbowax 20M + SE-30) and polar stationary liquids (Carbowax 20M) were used. The thickness of the ultra-thin film columns was determined by weighing the capillaries before and after coating of the capillary with stationary phase and conditioning, and varied from 0.05 to 0.5 mum. From the capacity ratios of s-triazines and n-alkanes measured in sections of an originally long dynamically coated column after it had been cut into several equal parts, the constancy of the film thickness along the whole column was judged. The film thickness was not uniform and increased along the whole column. It was found that glass capillary columns with non-polar stationary phase are not very suitable for the analysis of s-triazine herbicides, as tailing occurs with some of them. Symmetrical peaks and the separation of 17 from 18 analysed s-triazines were achieved on glass capillary columns coated with Carbowax 20M.

Chromatography, Gas↗

PubMed2003

Experimental comparison of three monoclonal antibodies for the class-selective immunoextraction of triazines. Correlation with molecular modeling and principal component analysis studies.

The specificity of three immunosorbents (ISs) based on different monoclonal anti-triazine antibodies has been characterized by extraction recoveries studies and with step elution experiments. Both indicated that the anti-dichloroatrazine IS is specific of terbutylazine and cyanazine. The anti-atrazine IS is specific of the chlorotriazines, whereas the anti-ametryn IS can trap all the triazines. This confirms the great influence of the hapten design on the specificity of the resulting antibodies, even if the target molecules are small. Moreover, the anti-ametryn IS is suitable for class-selective extraction of triazines contained in complex matrices. An approach designed to learn more about the specificity for a group of structurally related compounds of antibodies produced with a given compound is proposed and evaluated. Molecular modeling followed by principal component analysis has been used to obtain distribution maps with the relative position of each immunoconjugate and all the triazines. In all three cases, conclusions on specificity made with the analysis of the maps fit well with the experimental results. Consequently, molecular modeling coupled with principal component analysis seems to be a unique, inexpensive, and rapid tool to select the appropriate hapten providing highly specific or class-specific antibodies according to the given problem.

Antibodies, Monoclonal↗

PubMed2000

Remediation of s-triazines contaminated water in a laboratory scale apparatus using zero-valent iron powder.

Atrazine, propazine and simazine were tested separately and in mixture by batch procedure in a laboratory-constructed apparatus. 3.75 l of a buffered s-triazines pesticide solution was treated at room temperature by 325-mesh zero-valent iron powder (ZVIP) (20 g/l). High performance liquid chromatography was used to separate by-products and study the decline in the pesticide's concentrations. Results obtained show that the order of degradation was simazine, atrazine and then propazine. The half-lives (t1/2) of the s-triazines pesticides are, respectively, 7.4, 9.0 and 10.6 min when they are treated separately, and 9.8, 11.2 and 13.7 min when they are treated together under the same conditions. The final by-product obtained after 50 min of contact of simazine with ZVIP shows a shift to longer wavelength in its UV spectrum. A similar phenomenon is shown for atrazine and propazine. Identical primary by-products are produced and subsequently degraded to 4,6-(diamino)-s-triazine, which seems to be the major by-product of the reductive treatment process. Pathways for the degradation of the studied s-triazines by ZVIP are proposed.

Atrazine↗

PubMed2002

Triazines in the aquatic systems of the Eastern Chinese Rivers Liao-He and Yangtse.

The results of a one-year monitoring program on the two Eastern Chinese River systems, i.e. the Liao-He and the Yangtse, with special emphasis on the presence of triazine herbicides are presented. Sediment, suspended solids and water samples from both rivers were analyzed. Additionally, recovery experiments on the SPE-in-field-enrichment procedure and the extraction methods were performed. The samples were measured by gas chromatography coupled with mass spectrometry, electron capture detection and a newly developed mu-plasma atomic emission detector. A typical result of a one-year monitoring was obtained in case of the Liao-He: During winter, at low water period, low triazine values were found. A similar situation was found in early spring. Highest concentrations of atrazine up to 1600 ng/l were found in late spring in the water samples. Maximum concentrations of atrazine, simazine, propazine, simetryn and prometryn were observed in this season as a result of the actual use of triazines. Finally, after the high water period in autumn the triazine concentrations decreased. Additionally, atrazine adsorbed on sediment (up to 2.8 ng/g) and suspended solids was determined (up to 8 ng/l) during late spring sampling. Therefore, the logarithm of the organic carbon based sorption coefficient of atrazine could be calculated. Low levels of atrazine were measured in the water of Yangtse (up to 18.3 ng/l). The concentrations from all sampling points and sampling stations of a particular sampling date were similar, which indicates a homogeneous distribution of this herbicide. Due to the high discharge rate of up to 79,000 m3/s in case of the Yangtse a considerable mass transport of up to 57.5 kg per day atrazine may take place, even at concentrations below the European drinking water limit of 100 ng/l.

Adsorption↗

PubMed2002

Infrared and Raman spectra of 3,5-diamino-6-(o-C6H4X)-1,2,4-triazines [X = F, Cl, Br, CH3].

Raman and infrared spectra of four substituted 3,5-diamino-6-(ortho-substituted phenyl)-1,2,4-triazines, having ortho-fluoro, -chloro, -bromo and -methyl groups on the phenyl ring, are reported and discussed. Bands due to substituent sensitive phenyl vibrations are observed in both the Raman and infrared spectra. The Raman spectra of all four compounds have strong bands near 770 and 1330 cm(-1) which are assigned to the ring breathing vibration of the 1,2,4-triazine ring and an asymmetric triazine C-NH2 stretching vibration, respectively. A medium/strong band near 800 cm(-1) in the infrared spectra is attributed to an out-of-plane bending vibration of the substituted 1,2,4-triazine ring.

Amines↗

PubMed2003

Triazinic herbicide determination by gas chromatography-mass spectrometry in breast milk.

A solid-phase extraction procedure using a graphitized carbon black cartridge for extraction and cleaning of a series of five triazines (atrazine, deethylatrazine, deisopropylatrazine, ametryne and prometryne) from breast milk samples was developed. Using a chemometric methodology, the optimisation of both the analysis time and the triazinic herbicide separation by gas chromatography-mass spectrometry (GC-MS) was then carried out with only 18 experiments. Detection and quantification limits for 1ml breast milk sample were, respectively, 0.3 and 1 ppb for each studied compound. The variation coefficients were less than 5% over the concentration range from 1 to 100 ppb. The accuracy was between 98.63 and 104.62% for each triazinic herbicide. The recovery was between 58.64 and 63.22% for the concentration range from 1 to 100 ppb for each triazinic herbicide. The assay was successfully applied to the analysis of several breast milk samples.

Gas Chromatography-Mass Spectrometry↗

PubMed1989

Extraction and isolation of triazine herbicides from water and vegetables by a double trap tandem system.

The ability of a two-trap tandem system, one containing a nonspecific adsorbing material, such as graphitized carbon black (Carbopack B), and the other one filled with a sulfonic acid type silica-based cation exchanger (SCX), in extracting and isolating basic compounds from real matrices was evaluated by applying this device to the determination of triazine residues in water and vegetables. After percolation through the Carbopack column (extraction cartridge) of water samples or suitably prepared vegetable extracts, the two traps were connected in series, a methylene chloride-methanol mixture was allowed to flow along them, and triazines displaced from the extraction cartridge were selectively reabsorbed via salt formation on the strong acid exchanger column (isolation cartridge). After the column was washed, the analytes were removed from the isolation cartridge by 0.7 mL of aqueous methanol containing 70 mmol/L KCl. After the internal standard was added, the final solution was directly injected into the "high-performance" liquid chromatographic apparatus, which was operated isocratically in the reverse-phase mode with UV detection at 220 nm. The analytical recoveries of eight triazines from the two matrices considered ranged between 95% and 100%. The limits of sensitivity of this method for triazines were set at 10 ng/g of vegetable material and 10 ng/L of water by sampling 100 mL of it.

Chromatography, High Pressure Liquid↗

PubMed1990

Enzyme-linked immunosorbent assay compared with gas chromatography/mass spectrometry for the determination of triazine herbicides in water.

An enzyme-linked immunosorbent assay (ELISA) was compared to a gas chromatography/mass spectrometry (GC/MS) procedure for the analysis of triazine herbicides and their metabolites in surface water and groundwater. Apparent recoveries from natural water and spiked water by both methods were comparable at 0.2-2 micrograms/L. Solid-phase extraction (SPE) was examined also, and recoveries were determined for a suite of triazine herbicides. A significant correlation was obtained between the ELISA and GC/MS method for natural water samples that were extracted by SPE. Because ELISA was developed with an atrazine-like compound as the hapten with conjugation at the 2-position, it was selective for triazines that contained both ethyl and isopropyl side chains. Concentrations for 50% inhibition (IC50) were as follows: atrazine, 0.4 microgram/L; ametryne, 0.45 microgram/L; prometryn and propazine, 0.5 microgram/L; prometon, 0.7 microgram/L; simazine and terbutryn, 2.5 micrograms/L; hydroxyatrazine, 28 micrograms/L; deethylatrazine and deisopropylatrazine, 30 micrograms/L; cyanazine, 40 micrograms/L; didealkylatrazine had no response. The combination of screening analysis by ELISA, which requires no sample preparation and works on 160 microL of sample, and confirmation by GC/MS was designed for rapid, inexpensive analysis of triazine herbicides in water.

Enzyme-Linked Immunosorbent Assay↗

PubMed2001

Photocatalytic degradation of selected s-triazine herbicides and organophosphorus insecticides over aqueous TiO2 suspensions.

The photocatalytic degradation of selected s-triazine herbicides and organophosphorus insecticides was carried out in aqueous TiO2 suspensions under simulated solar light. The tested herbicides from the s-triazines group were atrazine, propazine, cyanazine, prometryne, and irgarol. The tested insecticides from the organophosphorus group were ethyl parathion, methyl parathion, ethyl bromophos, methyl bromophos, and diclofenthion. Degradation kinetics followed first-order reaction and has been monitored through gas chromatography. The degradation was fast with half-lives varying from 10.2 to 38.3 min depending on the nature and the structure of compounds. The generated transformation products (TPs) were formed via oxidation, dealkylation, and dechlorination for s-triazines and via oxidation and photohydrolysis for organophosphates. The TPs of irgarol, bromophos, and dichlofenthion were identified using solid-phase extraction (SDB-disks) and GC-MS techniques, and possible degradation routes were proposed showing similar degradation pathways as for other triazines and organophosporus pesticides. This work points out to the necessity of extended knowledge of the successive steps in a solar-assisted detoxification process.

Catalysis↗

PubMed2006

Chemistry of HIV-1 virucidal Pt complexes having neglected bidentate sp2 N-donor carrier ligands with linked triazine and pyridine rings. synthesis, NMR spectral features, structure, and reaction with guanosine.

Complexes of the types LPtCl2 and [L2Pt]X2 [L = substituted 3-(pyridin-2'-yl)-1,2,4-triazine] were synthesized and characterized by NMR spectroscopy and, for the first time, by X-ray crystallography in an effort to determine the coordination properties of this novel class of inorganic medicinal agents possessing HIV-1 virucidal activity. The agents containing either one or two sp2 N-donor bidentate ligands are referred to as ptt (platinum triazine) agents. The X-ray structures of three LPtCl2 compounds revealed the expected pseudo-square-planar geometry. The X-ray structure of [(pyPh2t)2Pt](BF4)2 [pyPh2t = 3-(pyridin-2'-yl)-5,6-diphenyl-1,2,4-triazine] has the expected trans relationship of the unsymmetrical L and is essentially planar, an unusual property for a Pt(II) complex with two bidentate sp2 N donors. HIV-1 is an RNA virus; the guanosine ribonucleoside (Guo) binds (MepyMe2t)PtCl2 at both (inequivalent) available coordination sites to form [(MepyMe2t)Pt(Guo)2]2+ [MepyMe2t = 3-(4'-methylpyridin-2'-yl)-5,6-dimethyl-1,2,4-triazine]. This adduct has four nearly equally intense Guo H8 signals attributed to two pairs of head-to-tail (HT) and head-to-head (HH) conformers, which interchange rapidly within each pair. However, equilibration between pairs requires rotation of the Guo cis to the MepyMe2t pyridyl ring, and the H6' proton on this ring projects toward the Guo and hinders Guo rotation about the Pt-N7 bond. Thus, the HT/HH pairs do not interchange; such behavior is rare. Guo did not add to [(MepyMe2t)2Pt]2+, a result suggesting the possibility that the virucidal activity of LPtCl2 and [L2Pt]2+ ptt agents arises respectively from covalent and noncovalent (possibly intercalative interactions favored by [L2Pt]2+ planarity) binding to biomolecular targets.

Anti-HIV Agents↗

PubMed2004

Nucleophilic radical substitution reaction of triazine herbicides with polysulfides.

Triazine herbicides are among the most widely used herbicides in the United States. Many triazine compounds are relatively stable under natural conditions and have become prominent contaminants in hydrologic systems. It was previously reported that chloro-s-triazine compounds were rapidly dechlorinated in water by polysulfides, and the reaction was assumed to be aromatic nucleophilic substitution (SNAr). In this study, we evaluated the effect of free radical inhibitors on the reaction rate of polysulfides with herbicides atrazine, simazine, and cyanazine. The reaction was significantly inhibited by radical scavengers oxygen and 1,4-benzoquinone, suggesting involvement of free radicals in the reaction. Spectral analysis of the reaction mixture using electron spin resonance showed that after the reaction, the free radical concentration in polysulfide solution substantially decreased. These evidences indicate that radical sulfur anions may also be involved in the reaction, likely via a free radical substitution reaction (SRN1) mechanism. Amendment of sodium tetrasulfide significantly reduced the leaching of atrazine or simazine from packed sand columns. Therefore, polysulfide salts may be potentially used to remove residues of triazine herbicides in environmental media.

Atrazine↗