Journal of Tea Science Research. 2015, Vol. 5, No. 9, 1-7
1
Research Report Open Access
Persistence of bifenthrin in tea and its transfer from black tea to tea brew
Seenivasan S. , Muraleedharan N.
1. The Institute of Environmental and Human Health, Texas Tech University, Lubbock–79415, Texas, USA
2. Tea Research Association, Tocklai Tea Research Institute, Jorhat-785008, Assam, India
Corresponding author email
Journal of Tea Science Research, 2015, Vol.5, No.9 doi: 10.5376/jtsr.2015.05.0009
Received: 11 Sep., 2015
Accepted: 23 Oct., 2015
Published: 16 Nov., 2015
© 2015
Seenivasan
, This is an open access article published under the terms of the Creative Commons Attribution License, which permits unrestricted use,
distribution, and reproduction in any medium, provided the original work is properly cited.
Preferred citation for this article:
Seenivasan S., Muraleedharan N.
, 2015, Persistence of bifenthrin in tea and its transfer from black tea to tea brew,
Journal of Tea Science Research, 5(9),
1-7
(
doi
Abstract
Field experiments were conducted at two places in Tamil Nadu (India) to determine the residues of bifenthrin in black tea.
Residues were quantified at different harvest intervals of ‘0’ (3 hr), 1
st
, 3
rd
, 5
th
, 7
th
, 10
th
and 14
th
day after acaricide application.
Persistence, dissipation pattern, half-life value and safe harvest interval of the acaricide in tea were calculated. Residues of bifenthrin
dissipated exponentially after application at both the locations and reached below the European Union maximum residue limit
(MRL) of 5 mg kg
-1
on the 10
th
day. Bifenthrin showed that like other acaricides it followed the first order dissipation kinetics.
Half-life values varied from 2.4 to 3.2 days for bifenthrin and a safe harvest interval of 10 days is suggested for tea at the
recommended dosage.
Keywords
Bifenthrin; Brew;Residues; Persistence; Dissipation; MRL
1 Background
Tea is a beverage endowed with numerous beneficial
health effects and it is imperative that this drink is
kept free of toxic contaminants like pesticide
residues and heavy metals. It is necessary to apply
pesticides, synthetic fertilizers and micro nutrients to
augment the productivity of tea gardens and to
protect the plants from pests and diseases. Synthetic
pyrethroids display a broad spectrum of
insecticidal/acaricidal activity coupled with low
mammalian toxicity and they have comparatively
low application rates for pest control, making them
environmentally more acceptable than the older,
more persistent and toxic organo-chlorine and
organo-phosphorous insecticides. They are often
used in rotation with other pesticides to delay
development of resistance to insecticides (Ripley et
al., 2001).
Bifenthrin[IUPACname2-methylbiphenyl-3-ylm-eth
yl(Z)-(1RS)-cis-3-(2-chloro-3,3,3-trifluoroprop-1-en
yl)-2,2-dimethyl cyclopropanecarboxylate] is an
off-white to pale tan waxy solid faint, slightly sweet
smell, belonging to pyrethroids chemical class, for
which the Acceptable Daily Intake was established
at the level of 0.015 mg kg-1 of body weight (Royal
Society of Chemistry, 1994). It is non-systemic
insecticide and acaricide which kills pests on contact
or on its ingestion along with plant substrate. There
are a number of highly desirable phys ical
characteristics for bifenthrin such as low water
solubility (0.1 mg l
-1
), high octanol-water coefficient
(Koc 2,30,000) and stability over a range 5-9.5
pH.
As tea is subjected to infusion prior to consumption,
residues of pesticides in tea and its transfer in
brew must be monitored prior to permitting the
consumption by human beings. A few reports are
available on the degradation of certain commonly
used pesticides and their residues in tea (Rajukkannu
et al., 1981; Singh & Agnihotri, 1984; Manikandan
et al., 2001, 2005 & 2006; Kumar et al., 2004; Sood
et al., 2004; Tewary et al., 2005; Seenivasan and
Muraleedharan, 2009). However, there is no
published information on the residues of bifenthrin
in black tea, under the climatic conditions of south
India. Hence, a study was undertaken to generate
data on the residues, persistence and dissipation of
bifenthrin in black tea when the tea crop was treated
