Environmental Analysis of Cypermethrin and its Degradation Products After Forestry Applications

Abstract

Cypermethrin and alphamethrin ([1R, cis, αS]- and [1S, cis, αR]-cypermethrin) are pyrethroid insecticides used in agriculture, forestry, and public health hygiene. After forestry applications of cypermethrin against bark beetles diastereo- and enantioselective analyses of pyrethroid residues are performed by gas chromatography (GC) with electron capture (ECD) and mass spectrometric (MS) detection, or by achiral and chiral high performance liquid chromatography (HPLC). The major soil metabolites of cypermethrin, i.e. 2,2-dimethyl-3-(1,1-dichlorovinyl)-cyclopropylic acid and 3-phenoxybenzoic acid, are analyzed as methyl esters by GC-MS with electron-impact (EI) ionization. On spruce bark cypermethrin persists several months as surface films of 1 μg/cm^2. In soil it is detected as long as seven months after treatment at levels of 0.15–0.7 μg/g. Sunlight-induced cis, trans isomerization on bark and leaves results in an excess of trans-cypermethrin isomers. In soil cis-cypermethrin isomers are more persistent than their corresponding trans-isomers. Enantioselective HPLC demonstrates chiral discrimination of a pair of trans-cypermethrin enantiomers. Analysis of soil metabolites is less meaningful since traces of the investigated products are formed from pyrethroid residues during the extraction and derivatization procedures.     

Dispersive liquid–liquid microextraction combined with high performance liquid chromatography-DAD detection for the determination of sulfonylurea herbicides in water samples

A new method for the determination of four sulfonylurea herbicides (metsulfuron-methyl, chlorsulfuron, bensulfuron-methyl and chlorimuron-ethyl) in water samples was developed by dispersive liquid–liquid microextraction coupled with high performance liquid chromatography-diode array detector. Parameters that affect the extraction efficiency, such as the kind and volume of the extraction and disperser solvent, extraction time and salt addition, were investigated and optimised. Under the optimum conditions, the enrichment factors were in the range between 102 and 216. The linearity of the method was obtained in the range of 1.0–100 ng mL^?1 with the correlation coefficients (r) ranging from 0.9982 to 0.9995. The method detection limits were 0.2–0.3 ng mL^?1. The proposed method has been successfully applied to the analysis of target sulfonylurea herbicides in river, stream and well water samples with satisfactory results.     

Dispersive solid-phase extraction followed by dispersive liquid–liquid microextraction for the determination of some sulfonylurea herbicides in soil by high-performance liquid chromatography

Dispersive solid-phase extraction (DSPE) combined with dispersive liquid–liquid microextraction (DLLME) has been developed as a new approach for the extraction of four sulfonylurea herbicides (metsulfuron-methyl, chlorsulfuron, bensulfuron-methyl and chlorimuron-ethyl) in soil prior to high-performance liquid chromatography with diode array detection (HPLC-DAD). In the DSPE-DLLME, sulfonylurea herbicides were first extracted from soil sample into acetone–0.15 mol L⁻¹ NaHCO₃ (2:8, v/v). The clean-up of the extract by DSPE was carried out by directly adding C₁₈ sorbent into the extract solution, followed by shaking and filtration. After the pH of the filtrate was adjusted to 2.0 with 2 mol L⁻¹ HCl, 60.0 μL chlorobenzene (as extraction solvent) was added into 5.0 mL of it for DLLME procedure (the acetone contained in the solution also acted as dispersive solvent). Under the optimum conditions, the enrichment factors for the compounds were in the range between 102 and 216. The linearity of the method was in the range from 5.0 to 200 ng g⁻¹ with the correlation coefficients (r) ranging from 0.9967 to 0.9987. The method detection limits were 0.5–1.2 ng g⁻¹. The relative standard deviations varied from 5.2% to 7.2% (n = 5). The relative recoveries of the four sulfonylurea herbicides from soil samples at spiking levels of 6.0, 20.0 and 60.0 ng g⁻¹ were in the range between 76.3% and 92.5%. The proposed method has been successfully applied to the analysis of the four target sulfonylurea herbicides in soil samples, and a satisfactory result was obtained.     

Einige bestrahlungsexperimente mit 2, 1-Benzisothiazolen

Some Irradiation Experiments with 2, 1-Benzisothiazoles 2, 1-Benzisothiazole ( 1 ) on irradiation with a mercury high-pressure lamp in benzene/diethylamine yields, after acetylation, 2-acetylamino-benzaldehyde ( 3 ; Scheme 1). Similarly, irradiation of 3-chloro-2, 1-benzisothiazole ( 2 ) in benzene/diethylamine leads to a mixture of 3-dimethylamino-2, 1-benzisothiazole ( 6a ) and N, N-diethyl-thioanthranilamide ( 7a ; Scheme 2). Benzisothiazole 6a , on irradiation, is not transformed into 7a . On the other hand, when 2 is irradiated in methanol a mixture of 3-methoxy-2, 1-benzisothiazole ( 4a ) and methyl anthranilate ( 5a ; Scheme 2) is obtained. In this case, 4a on irradiation in methanol or ethanol also yields 5a . No exchange of the methoxy group in 4a is observed when the irradiation is performed in ethanolic solution. Thus, 2, 1-benzisothiazoles 1 , 2 and 4a react photochemically by N,S-bond cleavage and hydrogen-atom abstraction from the solvent (Scheme 3). 3-Chloro-2, 1-benzisothiazole ( 2 ) shows a second photoreaction, i.e. nucleophilic exchange of the chloro substituent by methanol or diethyl amine. The latter reaction can also be observed thermally, e.g. in boiling methanol in the presence of methoxide ions.     

Traceable platinum(II) complexes with alkylene diamine-derived ligands: synthesis,characterization and in vitro studies

Diiodido- (6a/6b) and dichloridoplatinum(II) complexes (7a/7b) with fluorescent ligands 2-[(2-aminoethyl)amino]ethyl-2-(methylamino)benzoate (5a) and 2-amino-1-(aminoethyl)ethyl-2-(methylamino)benzoate (5b) were prepared and characterized by elemental analysis, ESI-MS analysis, fluorescence spectrometry, as well as ¹H, ¹³C, and ¹⁹⁵Pt NMR spectroscopy. All compounds have been tested against A2780 ovarian cancer, A549 lung carcinoma, and HT-29 colon cancer cell lines using sulforhodamine-B assay. The activity increased from ligand precursors, diiodido- to dichloridoplatinum(II) complexes, except against HT-29 cell line where diiodido and dichlorido expressed similar activity. These compounds enter the tumor cells and emit a bright fluorescence at ca. 470 nm, mainly targeting nuclei.     

Syntheses and structures of Cd(II) and Co(II) compounds of 4-[(3-pyridyl)methylamino]benzoate anion

Three coordination polymers containing Cd(II) and Co(II), connected via 4-[(3-pyridyl)methylamino]benzoate (L^?), have been synthesized in hydrothermal conditions. In [Cd(L)Cl] _n (1), adjacent Cd(II) cations are linked by carboxylates to give a dinuclear cluster. Pairs of L^? bridge the dinuclear cluster to form double helical chains, and these chains are further linked by Cl^? to produce a 4-connected net with (4²?·?6³?·?8) topology. [CdL₂] _n (2) contains 1-D ladder-like chains. The packing structure displays a 3-D supramolecular structure, with π?···?π interactions stabilizing the framework. [CoL₂] _n (3) has a 2-D extended supramolecular structure via π?···?π interactions of 1-D coordination polymers of 3. The crystal structures of 1–3 have been determined by single-crystal X-ray diffraction. Luminescent properties for 1 and 2 are discussed.     

Syntheses and crystal structures of mononuclear,tetranuclear and hexanuclear organotin compounds with derivatives of p -aminobenzoic acid

Four organotin(IV) compounds, [Bu₆Sn₆O₆(L¹)₆] (1), [Bu₆Sn₆O₆(L²)₄(L³)₂] (2), [Bu₈Sn₄O₂(L²)₄] (3) and [Ph₃Sn(L²)] (4), were obtained by reactions of BuSnOH, Bu₂SnO and Ph₃SnOH with 4-((6-chloropyridin-3-yl)methylamino)benzonic acid (HL¹), 4-((pyridin-2-yl)methylamino)benzonic acid (HL²) and p-aminobenzoic acid (HL³). 1 is a hexameric cluster, existing in a drum-like structure with prismatic Sn₆O₆ core. Compound 2 is a mixed drum, containing two kinds of carboxylic acid anions. Compound 3 possesses a Sn₄O₄ ladder structure. In 2 and 3, two-dimensional supramolecular structures are formed by the intermolecular hydrogen-bonding interactions. Compound 4 is a monomer with a dimer formed through π–π stacking between adjacent L² anions. Compounds 1–4 were characterized by elemental analyses and IR spectra.     

SUBSTITUTED 4,5-DIOXO-1,3-DIAZA-2λ3,4λ4-DIPHOSPHOLANE AND RELATED COMPOUNDS

Abstract

Cyclization of 1 with 2 yielded the title compound 3, which was transformed into the corresponding 1,3,2,4-diazadiphospholanes 4 and 5 by using DMSO or sulfur respectively. The addition reaction of 3 with butanedione gave 3,4-di-oxo-1-phenyl-2,5-diaza-6,9-dioxa-1λ⁵,3λ⁴-diphosphaspiro[4,4]nonane 6. The structures of 3, 4 and 5 were confirmed by elemental analysis, IR, NMR and GC-MS. Although 6 could not be isolated in pure form because of its rapid decomposition, the ₃₁P NMR data indicated its existence. It was found that there were cis- and trans-isomers in 3, 4, 5 and 6.     

Development of an Enzyme Immunoassay for the Determination of the Herbicide Metsulfuron-Methyl Based on Chicken Egg Yolk Antibodies

Abstract

The development of an indirect competitive enzyme immunoassay for the sulfonylurea herbicide metsulfuron-methyl (MSM) is described. In contrast to traditional antibody generation in mammals, this extremely sensitive method is based on chicken egg yolk antibodies (IgY). They were raised in laying hens using an MSM-derivative-BSA hapten as immunogen. With a 1:10000 dilution of the antibody solution and a coating antigen (MSM-derivative-KLH) concentration of 10 μg L^?1 the IC₅₀ value achieved for the target analyte was 0.4 μg L^?1. The least detectable dose was established at 13 ng L^?1. Cross-reactivity was tested with 5 structurally related compounds, where only sulfometuron showed a significant binding. The ELISA was tested with spiked tap and surface water samples. This paper, for the first time, demonstrates the production of high-affinity IgY antibodies for a herbicide compound.     

GC-MS Derivatization Studies: The Formation of Dexamethasone MO-TMS

Abstract

The 16α-methyl group in dexamethasone increases drastically the steric hindrance to reaction of both the 20-ketone and 17α-hydroxyl groups, as shown by kinetic studies with GC-MS techniques. A procedure is described for the preparation of the MO derivative (reaction et 60[ddot]C for 3 hr) and complete conversion of all hydroxyl groups to TMS ether groups (reaction at 100[ddot]C for 6 hr). The resulting MO-TMS derivative is thermostable and suitable for use in GC-MS methods. The procedures usually employed in urinary steroid studies are satisfactory for prednisone and prednisolone.     

ACTION DES CYANOARYLIDENES ACTIVES SUR LES β -CETO- δ -CARBETHOXYPHOSPHONATES ET PHOSPHINEOXYDES: SYNTHESE DE 2-AMINO-6-(PHOSPHONOMETHYL)-4H-PYRANES

The reaction of β-keto-δ-carbethoxyphosphonates and phosphineoxides 1 with active cyanoarylidenes 2 in basic conditions provides a convenient access to the new 2-amino-6-(phosphonomethyl)-4H-pyranes 3. The reaction is found to be highly regioselective. The structure of all obtained products is confirmed by NMR ( ¹ H, ³¹ P, ¹³ C), IR spectroscopy, and in some cases by mass spectrometry.     

Photochemische Synthesen potentiell hypoglykämisch wirkender 3-Oxazoline

Photochemical Syntheses of 3-Oxazolines which Possibly Exhibit Hypoglycemic Activity Reactions of photochemically generated benzonitrile methylides 2 with carbonyl compounds 3 yielded 3-oxazolines of the types 5 and 6 (Scheme 1). Photooxidation of 5-[p-(dimethylamino)phenyl]-2,2-dimethyl-4-phenyl-3-oxazoline ( 5a ) gave 4′-(2,2-dimethyl-4-phenyl-3-oxazolin-5-yl)-N-methylformanilide ( 6r ) which could be transformed to 2,2-dimethyl-5-[p-(methylamino)phenyl]-4-phenyl-3-oxazoline ( 6s ) by photodecarbonylation. Thirty 3-oxazolines of types 5 and 6 have been synthesized and tested by oral and/or intraperitoneal administration to starved rats and obese-hyperglycemic mice.     

A New Method for the Measurement of Airborne Formaldehyde Using Derivatization with 3,5-Bis(Trifluoromethyl) Phenylhydrazine and Analysis by GC-ECD and GC-MS/SIM

Abstract

A new method was developed and described for the measurement of airborne formaldehyde using derivatization with 3,5-bis(trifluoromethyl)phenylhydrazine (TFMPH) coated onto silica solid phase extraction cartridges. Analysis by GC-ECD provides a detection limit of 74 ng formaldehyde per sample. A field study was conducted to compare the use of TFMPH to 2,4-dinitrophenylhydrazine (DNPH) and NIOSH method 3500 (chromotropic acid, CTA). Samples were collected from indoor and outdoor environments known or suspected to contain formaldehyde. Use of TFMPH with GC-ECD analysis correlates well with both methods (R²=0.93, slope=1.07 vs. DNPH; R²=0.99, slope=1.06 vs. CTA). Spiked samples were shown to be stable at least 7 days when stored at –20 °C. Analysis of samples by GC-MS with selected ion monitoring (GC-MS/SIM) also proved feasible. Laboratory and field results show the use of TFMPH to be viable for quantifying airborne formaldehyde in occupational and environmental samples.     

A new method for the synthesis of 4H-1,3,4-thiadiazino[5,6-b]quinoxalines

The reaction of 6-chloro-2-[1-methyl-2-(Mmemylthiocarbamoyl)hydrazino]quinoxaline 4-oxide 5 with acetic anhydride or trifluoroacetic anhydride resulted in dehydrative cyclization to give 2-(N-acetyl)-memylamino-8-chloro-4-methyl-4H-1,3,4-thiadiazino[5,6-b]quinoxaline 6 or 8-chloro-2-(N-trifluoroacetyl)methylamino-4-methyl-4H-1,3,4-thiadiazino[5,6-b]quinoxaline 9 , respectively. The oxidation of compound 6 or 9 with 2-fold molar amount of m-chloroperbenzoic acid afforded the 4H-1,3,4-thiadiazino-[5,6-b]quinoxaline 1,1-dioxide 8 or 13 , respectively. The acetyl group of compound 6 was hardly hydrolyzed, but the trifluoroacetyl group of compound 9 was easily hydrolyzed to change into 8-chloro-4-methyl-2-memylamino-4H-1,3,4-thiadiazino[5,6-b]quinoxaline 10 . The acylation of compound 10 with acetic anhydride, trifluoroacetic anhydride, phenyl isocyanate, and chloroacetyl chloride furnished the 2-(N-acetyl)methylamino 6 , 2-(N-trifluoroacetyl)methylamino 9 , 2-(1-methyl-3-phenylureido) 11 , and 2-(N-chloroacetyl)methylamino 12 derivatives, respectively.     

Nuclear hydroxylated metabolite of fluradoline (2-fluoro-11-[(β-methylamino)ethylthio]dibenz[b,f]oxepin hydrochloride). Identification and synthesis

Fluradoline (2-fluoro-11-[β-(methylamino)ethylthio]dibenz[b,f]oxepin), a novel analgesic with an unique profile, was found to be extensively metabolized in man as well as in other species. One of the major metabolites of this drug appeared to be a nuclear hydroxylated derivative of the parent compound, and the site of enzymatic hydroxylation was established to be C(7) by using high-field proton nuclear magnetic spectroscopy. This structural assignment was subsequently confirmed by the synthesis of an authentic sample of 2-fluoro-7-hydroxy-11-[β-(methylamino)ethylthio]dibenz[b,f]oxepin ( 2a ).     

Comparison of the Leaching Behaviour of Alachlor and its Metabolites Under Field and Laboratory Conditions

Abstract

The aim of the investigation was to evaluate whether the results of field studies and those obtained from soil column experiments are comparable in order to describe leaching behaviour of pesticides. The fate of Alachlor and its metabolites 2,6-diethylaniline and 2-chloro-2′,6′-diethylacetanilide are described in this paper. Field leaching study and laboratory soil column experiments carried out with the formulated herbicide LASSO gave similar results. Applied Alachlor remained mostly in the top 10cm soil layer representing a limited mobility. Very small amounts of Alachlor in ground and percolated water indicated only a slight leaching potential. The calculated half-life of 15 days and 90% loss after 335 days demonstrate a remarkable persistence of alachlor. Only 2-chloro-2′,6′-diethylacetanilide but not 2,6-diethylaniline was detected in soil and percolated water. It is still uncertain if these residues originate from the formulated product or result partially from “metabolism”.

Column experiments with the same soil carried out under undisturbed conditions are a simple alternative to field studies and allow quantitative estimations. The column experiments support the assumption that most of the alachlor that cannot be found after application is not lost by wind drifting or volatilization but due to formation of bound residues.     

A Convenient Synthesis of 1-Amino-4-methyl-4H-3-thia-4,5a,10-triazacyclopenta[a]fluoren-5-ones and Some New 2,3-Dihydro-1,3,4-thiadiazoles

1-amino-4-methyl-4H-3-thia-4,5a,10-triazacyclopenta-[a]fluoren-5-one and 6-methyl-6H-,9H-thia-4b,6,9,11,12-pentaazaindeno[1,2-a]-fluorene-5,8-dione derivatives were prepared from 2-methyl-1-oxo-3-thioxo-2,4,9b-trihydropyrimidino[1,6-a] benzimidazole-4-carbonitrile. Also, 2,3-dihydro-1,3,4-thidazoles were synthesized via a reaction of hydrazonoyl chlorides with 3-(methylamino)-2-substituted 3-thioxopropanenitrile. Structures of newly synthesized compounds were elucidated on the basis of elemental analyses, spectral data, and alternative methods synthesis whenever possible.     

Synthesis of Some Novel N-Substituted Phthalazinone and Pyridopyridazinone Derivatives

Phthalazinone and pyridopyridazinone derivatives 3, 5, and 9 were prepared via reaction ofappropriate lactams 2 and 8 with 2-bromoethylphthalimide, N-tosylaziridine, and N,O-ditosyl derivatives of N-methylethanolamine in a two-step process in the presence of MeONa/MeOH or NaH/dimethylformamide (DMF). Starting compounds 2 and 8 were obtained by reaction of hydrazine hydrate with isoindolinones 1 or azaisoindolinones 6. Selected N-(2-phthalimidoethyl)-phthalazinones were converted into corresponding 2-[2-(methylamino) ethyl]- derivatives in satisfactory yields by treatment with hydrazine.     

Sulfur-34 as an Internal Standard for the Quantitation of Environmental Sulrur by Combined Gas Chromatography -Mass Spectrometry

Abstract

The quantitative analysis of sulfur by combined gas chromatography-mass spectrometry (GC-MS) can be effected using ³⁴S-enriched sulfur as an internal standard.     

Identification of 5-(3,4-Dihydroxyphenyl)-5-Phenylhydantoin: A Metabolite of 5,5-Diphenylhydantdin (Dilantin1) in Rat Urine

Abstract

Using radioisotope tracer technics and GC-mass spectrometry, a new metabolite of 5,5^?diphenylhydantoin present in rat urine has been dentified as 5-(3,k-dihydroxyphenyI)-5-phenylhydantoin. This catechol represented about 2% of the total metabolites excreted in rat urine folowing administration of diphenylhydantoin in the diet for over two weeks