Persistence of Cypermethrin and Decamethrin Residues in/on Brinjal Fruits

Full text

Persistence of Cypermethrin and Decamethrin Residues
in/on Brinjal Fruits
Prabhjot Kaur •G. S. Yadav •Reena Chauhan •
Beena Kumari
Received: 20 April 2011 / Accepted: 25 August 2011 / Published online: 25 September 2011
ÓSpringer Science+Business Media, LLC 2011
Abstract Residues of cypermethrin and decamethrin were
estimated in brinjal fruits by gas liquid chromatography
following single application of Cymbush 25 EC @ 43.75 and
87.50 g a.i./ha and of Decis 2.8 EC @ 11.20 and 22.40 g a.i./
ha at fruiting stage. The average initial deposits of cyper-
methrin 0.600 and 1.095 mg kg
-1
and of decamethrin
0.430 and 0.900 mg kg
-1
were observed for single and
double dose, respectively. Residues reached below maxi-
mum residue limit (MRL) value of 0.2 and 0.05 mg kg
-1
on
third and seventh day for cypermethrin and decamethrin,
respectively. The half-life values (t
1/2
) were worked out to be
1.16, 1.18 days for cypermethrin and 1.33, 1.42 days for
decamethrin at single and double dose, respectively fol-
lowing first order kinetics. Washing and washing followed
by boiling/cooking processes were found to be effective in
reducing the residues of both the insecticides in brinjal fruits.
Maximum reduction (31–42%) and (26–37%) was observed
by washing followed by boiling/cooking for cypermethrin
and decamethrin, respectively.
Keywords Cypermethrin Decamethrin Brinjal 
Residues Half-life period Processing
Vegetables are the fresh and edible portion of the herba-
ceous plants and essential components of human diet.
These are highly beneficial for the maintenance of human
health and prevention of diseases (Hanif et al. 2004). But
for better yield and quality, insecticides are repeatedly
applied during the entire period of growth and sometimes
even at the fruiting stage. About 10–12% of the total
pesticides are used on fruit and vegetable crops. Their
persistent use leads to build up of toxic residues on crop
produce, which may exert adverse effects on human health
in addition to disturbing ecosystem (Kumari et al. 2003).
This problem is more prevalent in vegetables as they
absorb insecticides and often create health hazards to
human beings while consuming fresh or without much
processing. Among vegetables, brinjal or egg plant (Sola-
num melongena L., aubergine) is one of the important
vegetable grown and consumed in India and other tropical
countries. After potato, it ranks as the second highest
consumed vegetable in India along with tomato (Mam-
moun et al. 2004). In 2008–2009, total area under brinjal
cultivation was 0.6 million ha with production of
10.37 million tonnes. This crop is vulnerable to attack from
several insect pests like jassids, white flies, caterpillars,
etc., Leucinodes orbonalis G. (shoot and fruit borer) is
considered to be the key pest. Management of this insect
pest of brinjal plant is difficult since it harbors inside the
shoot and fruit portions of eggplant (Nair 1986; Regupathy
et al. 1989; Sardana et al. 2004). Several insecticides
belonging to organochlorine, organophosphorus, cyclodi-
enes, and synthetic pyrethroids have been evaluated to
manage this pest (Mukherjee and Gopal 1992). Now a
days, mostly pyrethroids are used for insect-pest control
because they degrade quickly in soil, get rapidly metabo-
lized, virtually have zero mobility in soil and excreted by
animals. Among the various insecticides, cypermethrin and
decamethrin are low dose insecticides used extensively for
the control of various insect pests on vegetables in India.
Since farmers indiscriminately apply a cocktail of insecti-
cides on vegetable crops, thus the increasing amount of
pesticide residues in vegetables has been a major concern
P. Kaur G. S. Yadav R. Chauhan B. Kumari (&)
Department of Entomology, CCS Haryana Agricultural
University, Hisar, Haryana 125004, India
e-mail: beena@hau.ernet.in; beenakumari.958@rediffmail.com
123
Bull Environ Contam Toxicol (2011) 87:693–698
DOI 10.1007/s00128-011-0395-8

to the consumers. To ensure safe consumption of food
commodities, there is a need to develop methodologies to
dislodge pesticide residues from them. The present study
was undertaken to study the persistence behaviour of these
two pyrethroids following spray application and effect of
kitchen processes like washing and washing followed by
boiling/cooking on reduction of residues of cypermethrin
and decamethrin from brinjals fruit.
Materials and Methods
Brinjal (Variety BR 112) crop was raised and transplanted in
a plot size of 2.4 m 92.1 m according to the recommended
agronomical practices in the Research Field of Entomology,
CCS Haryana Agricultural University, Hisar during Kharif
season (summer season, from April to November) 2009–
2010. Cypermethrin (Cymbush 25 EC) at the rate of 43.75
(T
1
) and 87.50 (T
2
) and decamethrin (Decis 2.8 EC) at the
rate of 11.20 (T
1
) and 22.40 (T
2
) g active ingredient (a.i.)
ha
-1
were applied in triplicate along with control in ran-
domised block design (RBD) at fruiting stage of brinjal crop.
In control plots, only water was sprayed.
Brinjal fruit (1 kg) samples were collected randomly on
0 day (1 h after spray), 3, 7, and 10 days after treatment in
three replicates from both the trials. Samples collected from
field were analyzed at three stages i.e. raw, after washing
and washing followed by boiling/cooking to determine
residues of cypermethrin and decamethrin. The composite
brinjal samples were divided into three potions, one portion
was processed as such second after washing and third one
after washing followed by boiling/cooking. Washing was
performed by placing brinjal fruits in a container and rinsed
under tap water for 30 s, with gentle rotation by hand as
described by Walter et al. (2000) and blotted dry with a
paper towel and divided into two parts. One part was used
for washing and second for boiling. For boiling/cooking, in
25 g washed sample of brinjal 10 mL water was added and
boiled till softness of fruit pieces. Effect of processing was
studied in 0 and 3 days samples only.
All the solvents (hexane, acetone, n-hexane) were pro-
cured from Merck and glass distilled before use. Activated
charcoal and neutral alumina were of Analytical Grade.
Technical standard of cypermethrin and decamethrin were
procured form Sigma-Aldrich.
Extraction and clean-up was performed as per method of
Dikshit et al. (2001). Representative 25 g of the finely
chopped sample was extracted with 100 mL acetone by
shaking on mechanical shaker for 1.5 h. Filtered the extract
and partitioned thrice with hexane in separatory funnel
Table 1 Residues (mg kg
-1
) of cypermethrin in brinjal
Days after
treatment
Single dose (43.75 g a.i./ha) Double dose (87.50 g a.i./ha) Mean
Average residues
a
(mg kg
-1
)±SD
Dissipation (%) Average residues
(mg kg
-1
)±SD
Dissipation (%)
0 0.600 ±0.015 – 1.095 ±0.081 – 0.848
3 0.100 ±0.002 83.33 0.189 ±0.0008 82.73 0.145
7 0.043 ±0.004 92.83 0.084 ±0.006 92.32 0.064
10 0.030 ±0.003 95.00 0.065 ±0.005 94.06 0.048
Mean 0.193 0.358
Correlation coefficient
r=-0.9456; t
l/2
=1.16 day
Correlation coefficient
r=-0.9357; t
l/2
=1.18 day
CD (pC0.05) for days =0.009, for dose =0.006, for days 9for dose =0.012
a
Average of three replicates; MRL: 0.2 mg kg
-1
Fig. 1 Linear plot for first order kinetics of cypermethrin dissipation
in brinjal
694 Bull Environ Contam Toxicol (2011) 87:693–698
123

after diluting with 10% solution of sodium chloride. The
organic layers were pooled and concentrated on rotary
vacuum evaporator to reduce the volume approximately to
10 mL. Glass column (60 cm 922 mm i.d.) was packed
compactly with activated charcoal and neutral alumina (5:1
w/w). Prewetted the column with 40 mL of hexane, loaded
the concentrated extract in the column and eluted with
100 mL solution of hexane: acetone (1:1 v/v) at flow rate
of 4 mL/min. Concentrated the eluate on vacuum evapo-
rator followed by gas manifold evaporator. Final volume
was made to 2 mL in n-hexane for GC analysis.
A Shimadzu Gas Chromatograph GC-2010 equipped
with electron capture detector (ECD)
63
Ni and a capillary
column HP-1 (30 m 90.32 mm i.d. 90.25 lm film
thickness of 95% dimethyl and 5% diphenyl polysiloxane)
was used for residue analysis of cypermethrin and deca-
methrin. The operating parameters of the instrument were:
Oven temperatures (°C) 150 (5 min) ?8°C min
-1
?190
(2 min) ?15°C min
-1
?280 (10 min), injection port
280°C and detector 300°C. Flow rate of nitrogen (carrier
gas) was 60 mL min
-1
, 2 mL min
-1
through column and
split ratio 1:10. Under these operating conditions, the
retention times of cypermethrin were observed as 20.834,
20.955, 21.082 min and for decamethrin 23.597 min.
Results and Discussion
The percent recoveries at the fortification levels of 0.25 and
0.50 mg kg
-1
of cypermethrin and decamethrin were in the
range of 87.11–89.63 and 95.10–91.57, respectively. The
residue data of cypermethrin on brinjal are presented in
Table 1. The experimental data reveled that the initial
deposit for cypermethrin at single and double dose were
0.600 and 1.095 mg kg
-1
, respectively. The residues dis-
sipated with time by 83.33% and 82.73% in 3 days at
respective doses. After 3 days, there was slow dissipation
of cypermethrin residues till 10 days.
Although the dissipation rate was slightly slow but kept on
increasing day by day and about 95% of residues dissipated
after 10 days with half-life period of 1.16 and 1.18 days for
single and double doses, respectively. The dissipation pat-
tern followed the biphasic first order kinetics (Fig. 1). Res-
idues of cypermethrin from both the doses reached below
maximum residue limit (MRL) of 0.2 mg kg
-1
in 3 days.
Hence forth from consumer’s health point of view, a safe
waiting period of 3 days is suggested. Statistically analysed
data using ANOVA showed that irrespective of the duration,
at single dose, significantly less residues (0.193 mg kg
-1
)
were recorded than the double dose (0.358 mg kg
-1
)
(CD =0.006; p=0.05). With increase in duration, level of
residues decreased significantly (CD =0.009; p=0.05).
Interaction between duration and doses were also significant
(CD =0.012; p=0.05). This suggested that single dose has
Table 2 Residues (mg kg
-1
) of decamethrin in brinjal
Days after
treatment
Single dose (11.20 g a.i. ha
-1
) Double dose (22.40 g a.i.ha
-1
) Mean
Average residues
a
(mg kg
-1
)±SD
Dissipation (%) Average residues
(mgkg
-1
)±SD
Dissipation (%)
0 0.430 ±0.008 – 0.900 ±0.005 – 0.665
3 0.090 ±0.007 79.06 0.210 ±0.008 76.66 0.150
7 0.005 ±0.001 98.83 0.022 ±0.002 97.55 0.014
10 0.003 ±0.001 99.30 0.010 ±0.004 98.88 0.007
Mean 0.132 0.286
Correlation coefficient
r=-0.9810; t
l/2
=1.33 day
Correlation coefficient
r=-0.9921; t
l/2
=1.42 day
CD (pC0.05) for days =0.018, for dose =0.013, for days 9for dose =0.025
a
Average of three replicates; MRL: 0.05 mg kg
-1
Fig. 2 Linear plot for first order kinetics of decamethrin dissipation
in brinjal
Bull Environ Contam Toxicol (2011) 87:693–698 695
123

Table 3 Effect of processing on residues (mg kg
-1
) of cypermethrin and decamethrin in brinjal
Days after
treatment
Single dose (43.75 g a.i.ha
-1
) Double dose (87.50 g a.i.ha
-1
)
Initial deposit
(mg kg
-1
)
a
±SD
WW?C Initial deposit
(mg kg
-1
)
a
±SD
WW?C
Cypermethrin
0 0.600 ±0.015 0.390 ±0.004 (35.00) 0.350 ±0.010 (41.66) 1.095 ±0.081 0.729 ±0.013 (33.42) 0.690 ±0.007
(36.98)
3 0.100 ±0.002 0.072 ±0.001 (28.00) 0.064 ±0.007 (36.00) 0.189 ±0.008 0.142 ±0.021 (24.86) 0.131 ±0.024
(30.68)
Days after
treatment
Single dose (11.20 g a.i. ha
-1
) Double dose (22.40 g a.i. ha
-1
)
Initial deposit
(mg kg
-1
)
a
±SD
WW?C Initial deposit
(mg kg
-1
)
a
±SD
WW?C
Decamethrin
0 0.430 ±0.008 0.310 ±0.001 (27.90) 0.270 ±0.025 (37.20) 0.900 ±0.005 0.675 ±0.007 (25.00) 0.607 ±0.006
(32.55)
3 0.090 ±0.007 0.070 ±0.002 (22.22) 0.062 ±0.002 (31.11) 0.210 ±0.008 0.167 ±0.001 (20.47) 0.156 ±0.005
(25.71)
Figures in parenthesis are the percent reduction of residues
a
Average of three replicates; Wwashing; W?Cwashing followed by boiling/cooking
696 Bull Environ Contam Toxicol (2011) 87:693–698
123

significantly less residues as compared to double dose and
with increase in duration, level of residues decreased sig-
nificantly in both the doses by 10 days from brinjal fruits.
Singh and Kalra (1992) reported that initial deposit of cy-
permethrin (@ 100 g a.i. ha
-1
) was 0.73 mg kg
-1
in brinjal
which declined to 0.61 mg kg
-1
, 1 day after treatment and
0.08 mg kg
-1
after 10 days of spraying. They also reported
a dissipation of 94% which is in conformity with the present
findings.
Residue data pertaining to decamethrin have been pre-
sented in Table 2. As clear from the data, initial deposit of
0.430 mg kg
-1
at the rate of 11.20 g a.i. ha
-1
dissipated to
the level of 0.090 mg kg
-1
after 3 days showing 79.06%
dissipation whereas at the rate of 22.40 g a.i. ha
-1
, almost
same extent of dissipation (76.66%) was observed when
the initial deposit of 0.900 mg kg
-1
dissipated to the level
of 0.210 mg kg
-1
.
Residues reached below MRL value of 0.05 mg kg
-1
after 7 days in both the doses. The insecticide dissipated
very fast just after its application in both the doses and
from third day onwards there was a gradual degradation/
dissipation of decamethrin residues till 10 days. With in
this period, 99.30% and 98.88% dissipation was recorded
in respective doses following a first order kinetics (Fig. 2)
with half life period of 1.33 and 1.42 days. Statistically
analysed data using ANOVA showed that irrespective of
the duration at single dose, significantly less residues
(0.132 mg kg
-1
) were recorded than the double dose
(0.286 mg kg
-1
) (CD =0.013; p=0.05). With increase
in duration, level of residues also decreased significantly
(CD =0.018; p=0.05). This suggested that single dose
has significantly less residues as compared to double dose
and with increase in duration, level of residues significantly
decreased in both the doses. Mondal et al. (1987) reported
that the initial deposits of decamethrin when applied @
0.02% and 0.04% varied from 0.046 to 0.090 ppm and
declined to 0.002–0.005 ppm on tenth day in brinjal fruits
which is in conformity with the present results. Raha et al.
(1993) reported first order kinetics and half life values of
decamethrin applied @ 0.0015% and 0.0030% on brinjal
fruits were 1.20–4.30 days which is also in confirmation
with present results.
Effect of Processing
Brinjal fruits were subjected to processing like washing,
washing followed by boiling/cooking in order to investi-
gate the reduction of residues of cypermethrin and deca-
methrin from 0 to 3 days samples. The data pertaining to
this experiment is presented in Table 3.
It has been observed that washing of 0 day brinjal fruits
with water reduced 33.42–35.00% and 25.00–27.90% res-
idues of cypermethrin and decamethrin in both the
treatments, respectively. The corresponding reduction in
the residues due to washing followed by boiling/cooking
was 36.98–41.66% and 32.55–37.20%. On third day, effect
of washing as well as washing followed by boiling was
comparatively less effective in reducing the residues of
both insecticides. This may be due to less availability of
residues on surface as with passage of time, surface resi-
dues become less available due to penetration in the fruit.
From the results it has been concluded that both the
processes used in this study were more effective in
reducing the residues on 0 day because of availability of
residues on surface which could be dislodged easily. Raha
et al. (1993) reported that washing of brinjal fruits under
tap water removed decamethrin residues to an extent of
29–50% while washing followed by cooking reduced
deposits by 50–74% which are quite similar with the
present findings.
Reduction of cypermethrin residues on brinjal to the
level of 26% by washing and 37% by washing followed by
boiling was reported by Kumari (2008). Walia et al. (2010)
reported that washing of brinjal fruits under tap water
removed cypermethrin residues to an extent of 39.10% on
2nd day which are in conformation with the present results.
The similar trend in the decline of initial deposits of syn-
thetic pyrethroids on brinjal has been reported earlier by
Metwally et al. (1997) and Gill et al. (2001). The overall
results indicated that cypermethrin and decamethrin resi-
dues can be more effectively dislodged by washing fol-
lowed by boiling/cooking.
Acknowledgments The authors are grateful to the Head, Depart-
ment of Entomology, CCS Haryana Agricultural University, Hisar,
for providing necessary research facilities.
References
Dikshit AK, Srivastava YN, Lal OP (2001) Residue studies and
bioefficacy of b-cyfluthrin and k-cyhalothrin in brinjal (Solanum
melongena L.) fruits. Pestology 25(10):27–35
Gill K, Kumari B, Kathpal TS (2001) Dissipation of alphamethrin
residues in/on brinjal and tomato during storage and processing
conditions. J Food Sci Technol 8:3–16
Hanif R, Iaqbal Z, Iaqbal M, Hanif S, Rasheed MS (2004) Use of
vegetables as nutritional food: role in human health. J Agric Biol
Sci 1:339–342
Kumari B (2008) Effects of household processing on reduction of
pesticide residues in vegetables. ARPN J Agric Biol Sci
3(4):46–48
Kumari B, Kumari R, Madan VK, Singh R, Jagdeep Singh, Kathpal TS
(2003) Magnitude of pesticidal contamination in winter vegeta-
bles from Hisar, Haryana. Environ Monit Assess 87:311–318
Mammoun M, Sagar VR, Khurdiya DS (2004) Studies on preparation
of dehydrated brinjal slices. J Food Sci Techno 41:423–426
Metwally MES, Osman MS, Rushaid RA (1997) A high performance
liquid chromatographic method for the determination in vege-
tables and its application to kinetic studies after greenhouse
treatment. Food Chem 59:283–290
Bull Environ Contam Toxicol (2011) 87:693–698 697
123

Mondal A, Sukul P, Chowdhury A (1987) Residues and persistence of
decamethrin in brinjal under field conditions. Pestology
11(5):7–10
Mukherjee M, Gopal M (1992) Residue behaviour of fenval-
erate, tau-fluvalinate,lambda-cyhalothrin and monocrotophos in
eggplant (Solanum melongena L.) fruits. Pestic Sci 36:175–
179
Nair MRGK (1986) Insects and mites of crops of India. ICAR, New
Delhi, p 149
Raha P, Banerjee H, Das AK, Adityachaudhary N (1993) Persistence
kinetics of endosulfan, fenvalerate and decamethrin in and on
eggplant (Solanum melongena L.). J Agric Food Chem 41:923–928
Regupathy A, Palanichamy S, Chandramohan N, Gunathilakaraj KA
(1989) Guide on crop pests. Department of Agricultural
Entomology, Centre for Plant Protection Studies, Tamil Nadu
Agricultural University, Coimbatore, p 276
Sardana HR, Trivedi TP, Bambawala O, Sabir N, Singh RV, Arora S
(2004) Vegetable crops. In: Singh A, Sardana HR, Sabir N (eds)
Validated IPM technologies for selected crops. National Centre
for Integrated Pest Management, New Delhi, p 127
Singh IP, Kalra RL (1992) Determination of residues of deltamethrin
in brinjal fruit, leaves and soil. Indian J Entomol 54(2):218–227
Walia S, Boora P, Kumari B (2010) Effect of processing on
dislodging of cypermethrin residues on brinjal. Bull Environ
Contamn Toxicol 84:465–468
Walter JK, Arsenault TL, Pylypiw HM, Mattina MJI (2000)
Reduction of pesticide residue on produce by rinsing. J Agric
Food Chem 48:4666–4670
698 Bull Environ Contam Toxicol (2011) 87:693–698
123