Search results for "Captan"
showing 8 items of 8 documents
More about sampling and estimation of mercaptans in air samples
2013
[EN] Several strategies have been developed for sampling and determination of volatile thiols. The selectivity and sensitivity of the proposed methodologies are achieved by using a specific derivatizing reagent. The different procedures assayed are based on air sampling followed by derivatization of the analytes with OPA and isoleucine in alkaline solution. The derivatization products are separated and determined by liquid chromatography and fluorescence detection. To start, the derivatization conditions and stability of the derivates have been studied in order to establish the storage conditions. In general, the strategies studied consisted on trapping and detivatization the thiol compound…
Contribution à l'étude des « goûts de lumière » dans le vin de champagne *. 1. Aspects analytiques - Dosage des mercaptans et des thiols dans les vins
1977
<p style="text-align: justify;">Plusieurs accidents appelés « goûts de lumière » ou « goûts de réduit » ont été observés dans les vins de champagne au cours de ces dernières années. Dans ce travail, nous avons mis au point une méthode d'appréciation de ces goûts par dosage des groupements thiols ou mercaptans dans les vins. L'analyse comparative montre une bonne concordance entre la concentration en groupements thiols et l'appréciation gustative.</p><p style="text-align: justify;">+++</p><p style="text-align: justify;">For some years, accidents called « light tastes » or « reduced tastes » have been occured in Champagne wines; a method for thiols and mercaptans…
Genotoxicity of the fungicide dichlofluanid in seven assays
1991
Seven different endpoints for detection of genotoxicity have been used to demonstrate the DNA-altering properties of Dichlofluanid, a fungicide commonly used in viticulture pest control. Each endpoint (DNA synthesis inhibition test, alkaline viscosimetry, umu-test, alkaline filter elution, FADU-test, 32P-postlabeling, and electron microscopy) shows clear evidence of genotoxicity. These data indicate that application of the fungicide dichlofluanid may be mutagenic and/or carcinogenic for exposed humans.
Supramolecular functionalization and concomitant enhancement in properties of Au25 clusters
2014
We present a versatile approach for tuning the surface functionality of an atomically precise 25 atom gold cluster using specific host-guest interactions between ?-cyclodextrin (CD) and the ligand anchored on the cluster. The supramolecular interaction between the Au25 cluster protected by 4-(t-butyl)benzyl mercaptan, labeled Au25SBB18, and CD yielding Au25SBB18�?�CDn (n = 1, 2, 3, and 4) has been probed experimentally using various spectroscopic techniques and was further analyzed by density functional theory calculations and molecular modeling. The viability of our method in modifying the properties of differently functionalized Au25 clusters is demonstrated. Besides modifying their optoe…
Hepatic metabolism of diallyl disulfide in rat and man
2003
International audience; 1. The metabolism of diallyl disulphide was investigated in vitro with rat and human liver cell subfractions and ex vivo with an isolated perfused rat liver. 2. Diallyl disulphide was oxidized to diallylthiosulphinate by rat liver microsomes with an apparent K-m = 0.86 +/- 0.1 mM and an apparent V-max = 0.47 +/- 0.12 nmol min(-1) mg(-1) protein (mean +/- SE). Both cytochrome P450 (CYP) and flavin-containing monooxygenases were involved, with CYP2B1/2 and CYP2E1 being the most active CYP enzymes. 3. In rat and man, microsomal oxidation of allylmethyl sulphide to allylmethyl sulphoxide and allylmethyl sulphone also occurred, although at a low rate. Diallyl disulphide w…
In vivo antigenotoxic effects of dietary allyl sulfides in the rat
1997
The effects of dietary administration of diallyl sulfide (DAS), diallyl disulfide (DADS) and allyl mercaptan (AM) on the genotoxicity of different chemicals were studied in two experimental systems: (i) measurement of hepatic DNA single-strand breaks induced in rats by aflatoxin B1 (AFB1), N-nitrosodimethylamine (NDMA) or methylnitrosourea (MNU); (ii) mutagenicity of AFB1 or NDMA on Salmonella typhimurium TA100 using hepatic S9 from rats fed allyl sulfides as the activation system. All compounds strongly reduced hepatic DNA breaks induced by AFB1 and NDMA but did not modify the genotoxicity of MNU. In the Ames test, the mutagenicity of NDMA was strongly inhibited by hepatic S9 from rats fed…
Genotoxicity of six pesticides by Salmonella mutagenicity test and SOS chromotest.
1997
Abstract Two in vitro tests (Ames test and SOS chromotest), one for bacterial mutagenicity and one for primary DNA damage, were assayed to determine the genotoxic activity of 6 pesticides (atrazine, captafol, captan, chlorpyrifosmethyl, molinate and tetrachlorvinphos). Assays were carried out both in the absence and presence of S9 fractions of liver homogenate from rat (Sprague–Dawley) pretreated with Aroclor 1254. Captan and captafol were genotoxic on both the Ames test and the SOS chromotest. Comparisons with mutagenesis data in Salmonella indicated that the SOS assay detected as genotoxic the pesticides that were mutagenic on the Salmonella test. Non-genotoxic effects were not detected i…
Application of matrix solid-phase dispersion to the determination of a new generation of fungicides in fruits and vegetables.
2002
A method based on matrix solid-phase dispersion (MSPD) and gas chromatography to determine eight fungicides in fruits and vegetables is described. Fungicide residues were identified and quantified using nitrogen-phosphorus detection and electron-capture detection connected in parallel and confirmed by mass spectrometric detection. The method required 0.5 g of sample, C18 bonded silica as dispersant sorbent, silica as clean-up sorbent and ethyl acetate as eluting solvent. Recoveries from spiked orange, apple, tomato, artichoke, carrot and courgette samples ranged from 62 to 102% and relative standard deviations were less than 15% in the concentration range 0.05-10 mg kg(-1). Detection and qu…