http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15212264
Environ Sci Technol. 2004 May
15;38(10):2885-93.
Pesticide volatilization from plants:
improvement of the PEC model PELMO based on a boundary-layer
concept.
Wolters A, Leistra M, Linnemann V, Klein
M, Schaffer A, Vereecken H.
Forschungszentrum Julich GmbH, Institute of Chemistry and Dynamics
of the Geosphere IV: Agrosphere, 52425 Julich, Germany. a.wolters@fz-juelich.de
Calculation of pesticide volatilization
from plants as an integral component of pesticide fate models
is of utmost importance, especially as part of PEC (predicted
environmental concentrations) models used in the registration
procedures for pesticides. A mechanistic approach using
a laminar air-boundary layer concept to predict volatilization
from plant surfaces was compared to data obtained in a wind-tunnel
study after simultaneous application of parathion-methyl, fenpropimorph,
and quinoxyfen to winter wheat. Parathion-methyl
was shown to have the highest volatilization during the wind-tunnel
study of 10 days (29.2%). Volatilization
of quinoxyfen was about 15.0%, revealing a higher volatilization
tendency than fenpropimorph (6.0%), which is attributed
to enhanced penetration of fenpropimorph counteracting volatilization.
Predictions of the boundary-layer approach were markedly influenced
by the selected values for the equivalent thickness of the boundary
layer and rate coefficients, thus indicating that future improvements
of the approach will require a deeper understanding of the kinetics
of the underlying processes, e.g. phototransformation
and penetration. The boundary-layer
volatilization module was included in the European registration
model PELMO, enabling simultaneous calculation of volatilization
from plants and soil. Application of PELMO to experimental
findings were the first comprehensive PEC model calculations
to imply the relevant processes affecting the postapplication
fate of pesticides.
PMID: 15212264 [PubMed - indexed for MEDLINE]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12568578&dopt=Abstract
J Agric Food Chem
2003 Feb 12;51(4):1090-4
Influence
of Different Mineral and Organic Pesticide Treatments on Cd(II),
Cu(II), Pb(II), and Zn(II) Contents Determined by Derivative
Potentiometric Stripping Analysis in Italian White and Red Wines.
Salvo F, La Pera L, Di Bella G, Nicotina
M, Dugo G.
Dipartimento di Chimica Organica e Biologica, University of
Messina, Salita Sperone 31, 98166 Messina, Italy, and Dipartimento
di Entomologia e Zoologia Agraria, University of Napoli, Via
Universita 100, 80055 Napoli, Italy.
This paper deals with the use of derivative potentiometric stripping
analysis (dPSA) as a rapid and precise method to determine Cd(II),
Cu(II), Pb(II), and Zn(II) levels in red and white wine samples
from Sicily, Campania, and Tuscany and to investigate the possible
connection between the content of these metals and the pesticide
treatments used in vine-growing to control plant diseases and
pests. dPSA allowed direct quantitation of heavy metals in acidified
wines without any sample pretreatment. Mean recoveries of Cd(II),
Cu(II), Pb(II), and Zn(II) ranged from 95.5 to 99.2% for white
wine samples and from 96.1 to 100.0% for red wine samples. The
obtained results showed that Cd(II) was not found in any sample
and that Cu(II), Pb(II), and Zn(II) levels were always lower
than the toxicity limits in both fungicide- and water-treated
wines. Nevertheless, the contents of metals were increased in
samples from organic and inorganic pesticides treatment with
respect to the water-treated samples. In
particular, quinoxyfen,
dinocap-penconazole, and dinocap applications considerably
increased Cu(II) and Zn(II) contents in white and red wines.
The levels of lead were significantly raised by azoxystrobin
and sulfur treatments.
PMID: 12568578 [PubMed - in process]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11553131&dopt=Abstract
Contact Dermatitis
2001 Aug;45(2):119-20
No
abstract available
Occupational
allergic contact dermatitis caused by 5,7-dichloro-4-(4-fluorophenoxy)quinoline
(quinoxyfen).
Chowdhury MM, Chakrabarti A, Prais L,
Foulds IS.
Birmingham
Skin Centre, Dudley Road, Birmingham B18 7QH, UK.
PMID: 11553131 [PubMed - in process]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12233191&dopt=Abstract
Pest Manag Sci 2002
Sep;58(9):972-4
Quinoxyfen--resistance
management and sensitivity monitoring in wheat: 1995-2000.
Bernhard U, Leader A, Longhurst C, Felsenstein
FG.
Dow AgroSciences GmbH, Truderinger
Str. 15, 81677 Munich, Germany.
Wheat powdery
mildew, Blumeria (= Erysiphe) graminis DC f sp tritici Marschal
is one of the most important foliar diseases of cereals in Europe,
and has shown a high potential for adaptability in sensitivity
towards modern fungicides during the last 20 years.
Quinoxyfen is a surface-mobile fungicide from a new chemical
class that has been commercially used for the control of B graminis
in Europe since 1997. When the compound was launched,
a Resistance Management Strategy was implemented which included:
no seed treatments, no autumn use, a specified window of application
and recommendations for appropriate tank-mixing. To assess the
success of this Management Strategy, a European-wide resistance
monitoring programme was carried out between 1995 and 2000 using
spore trap sampling, and a whole plant assay. The mean EC50
values found by year were 0.060 mg litre-1 in 1995, 0.052 mg
litre-1 in 1996, 0.071 ml litre-1 in 1997, 0.039 mg litre-1
in 1998, 0.039 mg litre-1 in 1999 and 0.063 mg litre-1 in 2000.
No new sensitivity classes were found. The slight shift to lower
sensitivity in 1998 and 1999 was correlated with similar shifts
in three wildtype isolates, and was ascribed to experimental
variation. The monitoring programme will continue to assess
the long-term impact of the management recommendations on the
resistance status of quinoxyfen.
PMID: 12233191 [PubMed - in process]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12033804&dopt=Abstract
J Agric Food Chem
2002 Jun 5;50(12):3412-8
Erratum
in: J Agric
Food Chem 2002 Jul 17;50(15):4430
Method
development and fate determination of pesticide-treated hops
and their subsequent usage in the production of beer.
Hengel MJ, Shibamoto T.
University
of California, Davis, One Shields Avenue, Davis, California
95616, USA. mjhengel@ucdavis.edu
The fate of residues of seven agrochemicals (chlorfenapyr, quinoxyfen,
tebuconazole, fenarimol, pyridaben, and E- and Z-dimethomorph)
from the treatment on hops to the brewing of beer was studied.
First, a multi-residue analytical method was developed for the
determination of pesticide residues in spent hops, trub, wort,
and beer. Each matrix was validated over at least two levels
of fortification, for all seven compounds, in the ranges 0.05-5.0,
0.001-1.0, 0.001-0.05, and 0.0005-1.0 ppm for spent hops, trub,
wort, and beer, respectively. Recoveries ranged from 73 to 136%.
Second, the matrixes prepared from hops, which were treated
under commercial practices with each compound, were analyzed
using the method developed. The use of treated hops resulted
in the carryover of 0.001 ppm of tebuconazole, 0.008 Z-dimethomorph,
and 0.005 ppm of E-dimethomorph into the wort. The
bulk of the remaining residues of all seven compounds was found
on the spent hops. Following fermentation, all compounds
were found in levels less than 0.0005 ppm in beer, except Z-
(0.006 ppm) and E-dimethomorph (0.004 ppm). Third, when all
seven pesticides were spiked prior to the pitching of yeast
into clean wort, most of the nonpolar
compounds (chlorfenapyr, quinoxyfen, and pyridaben) partitioned
into the organic material (trub) which settled to the bottom,
while the more polar compounds (fenarimol, tebuconazole, and
E- and Z-dimethomorph) were generally distributed evenly between
the beer and the trub.
PMID: 12033804 [PubMed - indexed for MEDLINE]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11312786&dopt=Abstract
J Agric Food Chem
2000 Dec;48(12):6128-31
Fate
of quinoxyfen residues in grapes, wine, and their processing
products.
Cabras P, Angioni A, Garau VL, Pirisi
FM, Cabitza F, Pala M, Farris GA.
Dipartimento
di Tossicologia, Universita di Cagliari, via Ospedale 72, 09124
Cagliari, Italy. pcabras@unica.it
Quinoxyfen is a new fungicide that belongs to the family of
the quinolines, recently introduced to control powdery mildew
(Uncinula necator). In this paper the fate of quinoxyfen residues
from vine to wine and in their processing products was studied.
After the last of four applications at
the recommended rate, 0.38 mg/kg of residue was found on the
grapes, which is under the legal limit fixed in Italy (0.5 mg/kg).
The degradation rate was according to a pseudo-first-order kinetics
(r = 0.964) and the half-life was 7.24 days. Vinification was
carried out with and without maceration. During the vinifications
without maceration <50% of the residues passed from the grapes
to the musts. Separation of the lees (8%) from the must by centrifugation
caused no detectable residues in centrifuged must. At the end
of fermentation with and without maceration no quinoxyfen residues
were determinable in the wine. No effect on the alcoholic or
malolactic fermentation was observed even in the presence of
higher quinoxyfen concentrations than those found in the grapes
at harvest time. During fermentation, the yeasts partially degraded
the pesticides and completly adsorbed them. Bacteria, on the
other hand, do not have any degradative effect on the pesticides.
The raisins obtained by sun-drying did
not contain any residues, whereas those obtained by oven-drying
show the same amount of residues as in the fresh grapes.
During the sun-drying process the fruit weight decreased by
a factor of 4; the decrease in the oven-drying was equivalent.
Samples of dregs and liquid lees, fortified with high levels
of quinoxyfen. were double-distilled. The first dregs distillate,
with an alcohol content of 32.1%, did not show any residues,
whereas the first lees distillate, with
an alcohol content of 34.5%, showed 7% of the initial residues.
After the second lees distillation, the obtained product showed
an alcoholic content of 81.2% and no residues of quinoxyfen
(<0.01 mg/kg).
PMID: 11312786 [PubMed - indexed for MEDLINE]
From Toxline at Toxnet
PESTICIDE SCIENCE; 51 (3). 1997. 347-351.
Defining the resistance risk of the
new powdery mildew fungicide quinoxyfen.
HOLLOMON DW, WHEELER I, DIXON K, LONGHURST
C, SKYLAKAKIS G
IACR-Long Ashton Res. Stn., Dep. Agric. Sci., Univ. Bristol,
Long Ashton, Bristol BS18 9AF, UK.
BIOSIS COPYRIGHT: BIOL ABS. The new powdery mildew fungicide
quinoxyfen belongs to the novel quinoline class of chemistry.
Although its biochemical mode of action is unknown, quinoxyfen
does not act in the same way as other cereal fungicides. It
is a systemic protectant which inhibits the early stages of
mildew infection on a wide range of crops, and provides season-long
protection from a single early-season spray applied around GS
31. The base-line sensitivity profile of quinoxyfen was defined
for barley powdery mildew (Erysiphe graminis f. sp. hordei)
from over 340 field isolates collected from different parts
of the UK from 1991 onwards. Sensitivities ranged from <0.001
- 0.16 mg litre-1 with a mean of 0.003 mg litre-1. Current work
is extending the base-line sensitivity studies to wheat powdery
mildew (E. graminis f.sp. tritici), and includes isolates from
European trials, but so far this new data set has shown no differences
from barley powdery mildew. Quinoxyfen-resistant mutants were
ge [abstract truncated]
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