Investigation in Tea on Fate of Fenazaquin Residue and Its Transfer in Brew Q

Food and Chemical Toxicology 44 (2006) 596–600 www.elsevier.com/locate/foodchemtox

Investigation in tea on fate of fenazaquin residue and its transfer in brew q

Vipin Kumar, Dhananjay Kumar Tewary, Srigiripuram Desikachar Ravindranath, Adarsh Shanker *

Institute of Himalayan Bioresource Technology, Council of Scientiﬁc and Industrial Research, Palampur 176 061, HP, India

Abstract

Fenazaquin is a non-systemic acaricide/insecticide used widely in controlling mites and other related pests in fruits, vegetables and tea. The objective of this research was to investigate the disappearance trend in tea of fenazaquin residue level and its transfer in brew. Fenaz- aquin was applied on a tea crop at two rates, 125 and 250 g AI/ha in wet and dry seasons under field conditions. Samples (green shoots, made tea and its brew) were analyzed for fenazaquin and quantification was by high performance liquid chromatography using a UV detector. The residue dissipated faster in the wet season than in the dry season. Seven days after the treatment (normal round of plucking) the residues observed in the green shoots at the two rates were 2.17, 3.07 mg/kg and 2.04, 2.84 mg/kg in the wet and dry seasons, respectively. However, the degradation rale in both seasons followed first-order kinetics. Half-lives in green shoots were in range 1.43–1.70 and 2.10–2.21 days and in made tea 1.59–1.73 and 1.87–1.94 days for wet and dry seasons, respectively. During processing of green shoots to made tea considerable loss (42–70%) of residue was observed. The transfer of residue from made tea brew was in the range 3–22%. In brew residue were below 0.02 mg/l after 5 days of application at both the rates in either of the seasons. The estimated intake with brew (normal consumption of 10 cup/day/adult) thus would be below the acceptable daily intake for fenazaquin (0.005 mg/kg-body weight). To avoid health hazards due to the toxic effect of residues in brew, a waiting period for plucking the tea shoots after fenazaquin application of more than 5 days for both the seasons at recommended rate (125 g AI/ha) may be suggested and considered quite safe. 2005 Elsevier Ltd. All rights reserved.

Keywords: Fenazaquin; Residue; Tea; Brew; Transfer

1. Introduction case with most large-scale agricultural ventures, the chemical control of pests dominates the tea growing environ- The tea crop is subject to attack from a wide range of ment as the single most widely used pest control strategy insects and mite pests which besides causing crop loss dete- in almost all tea growing countries. One of the major disad- riorate the quality of the processed tea. As has been the vantages of pesticide use is that residue may remain in tea and may be transferred in infusion (brew) in amounts above maximum residue limits (MRLs). This could pose Abbreviations: AI, Active ingredient; ADI, Acceptable daily intake; health hazards to consumers. This problem is being viewed EC, Emulsion concentrate; FAO, Food and Agriculture Organization; HPLC, High performance liquid chromatography; MRL, Maximum res- seriously by international organizations (US EPA, Codex idue limit; ND, Not detected; US EPA, Environmental Protection Agency Alimenterious Commission, WHO and FAO of the United or United States; WHO, World Health Organization. Nations). In the past few years there has been a continuous q DOI of original article: 10.1016/j.fct.2003.10.004, 10.1016/j.fct.2005. search for acaricide/insecticides with broad spectrum activ- 10.009. q ity and minimum residual problems. IHBT Communication No. 0326. * Corresponding author. Tel.: +91 1894 230454; fax: +91 1894 230433. Fenazaquin (IUPAC name: 4-tert-butylphenethyl qui- E-mail address: [email protected] (A. Shanker). nazolin-4-yl ether), is a white to tan crystalline solid,

the laboratory each time at 0 (1 h after spraying), 1, 3, 5, 7, 9, 11, 14 and 21 H2 CH C 3 days after the treatment. H2C CH3 CH O 3 2.2. Reagent and apparatus

N 2.2.1. Analytical standards and working solutions An analytical standard of fenazaquin (active substance) and its com- N mercial grade formulation (Magister 10EC) were supplied by De-Nocil Crop Protection Ltd., India. A standard stock solution (1000 mg/l) was Fig. 1. Structure of fenazaquin. prepared in acetonitrile and the solutions required for preparing a standard curve (0, 0.1, 0.2, 0.4, 0.8 and 1.0 lg/ml) were prepared from the standard stock solution by serial dilutions. All the solvents and chemicals belonging to the quinazoline group (Fig. 1) of pesticides, used were of Analytical Grade from E. Merck. for which the acceptable daily intake (ADI) was established at the level of 0.005 mg/kg body weight/day (Dow Elanco, 2.2.2. Apparatus 1993). It is marketed mainly in two formulation types, A high performance liquid chromatograph, LaChrom–Merck, equip- ped with a LiChrospher 100 C18 (reverse phase) endcapped (5 lm) 200 g/l aqueous suspension concentrate and 100 g/l emul- column and a UV detector was used. The mobile phase was acetonitrile– sion concentrate under various trade names, e.g. Magister, water (80:20v/v) with 1 ml/min flow rate. The column oven was kept at Matador, Totem, Demitam and Magus. Fenazaquin is a 30 C. The best detection was attained at wavelength of 218 nm. The broad spectrum, non-systemic acaricidal compound, effec- volume of the injection was 10 ll. tive in controlling phytophagus mites infesting a variety of crops namely fruits and vegetables (Solomon et al., 2.2.3. Florisil column Glass columns (30 cm · 1.1 cm i.d.) with Teflon stopcocks were packed 1993) and tea (Shanker et al., 2001). It acts as an electron from the bottom with a glass wool plug and 2.5 cm of Merck brand transport inhibitor, acting at Complex I of the mitochon- activated Florisil (60–100 mesh) between the layers of anhydrous sodium drial respiratory chain (Hollingworth et al., 1992). This sulfate. specific acaricide/insecticide has generally no effect on ben- eficial insects including predaceous mites (Hollingworth 2.3. Tea leaves and infusion et al., 1992) and thus offers a desirable reason for its use in developing new strategies of integrated pest management The untreated control and treated green leaves from the field were processed in the laboratory’s mini manufacturing unit using conventional in tea. an orthodox tea manufacturing process. The manufacturing process, in Residue levels of many pesticides in tea and in its infu- brief, involved withering of shoots at ambient temperature for 15–20 h; sion have been reported (Chen et al., 1987; Chen and rolling (twisting and rupturing the tissue to express the juice) using a piezy Wan, 1988; Muraleedharan, 1994; Bhattacharya et al., roller for about 30 min with pressure followed by fermentation (oxidation) 1995; Jaggi et al., 2001). Residual studies of fenazaquin for 1–2 h at 25–30 C and 95% r.h. and finally drying in a tea dryer using hot air at 100 ± 5 C to a final moisture content of 2–3%. The made tea on some food commodities are available (Dow Elanco, was further subjected to an infusion process wherein 5 g of manufactured 1993). However, no studies have been found in the litera- tea was infused in 150 ml of boiling water. After 3 min of brewing, the ture on the dissipation in tea of fenazaquin residue and water extract was filtered through a (2-lm sieve) stainless steel filter, its transfer in brew from made tea (processed dry tea cooled and examined for residue transfer from made tea. The matrices leaves). The present study was therefore, undertaken to used for residue determination were the green shoots, made tea, the infusion prepared and the spent leaves left in the stainless steel filter. generate data in wet and dry seasons in tea on the persistence of fenazaquin (Magister) residue and its transfer from made tea to infusion in hot water. This would help 2.4. Extraction to establish adequate monitoring of the residue of this 2.4.1. Green leaves and made tea newly introduced acaricide/insecticides and its judicious Samples of green tea leaves (25 g) and made tea (10 g) were extracted incorporation in pest management strategies in tea fields. with 150 and 100 ml of dichloromethane, respectively by mechanical shaking for 2 h. Extracts were filtered through a Whatman No. 1 filter 2. Materials and methods paper containing 2 g of anhydrous sodium sulfate (impregnated with dichloromethane). 2.1. Field trials 2.4.2. Infusion and spent leaves Two field trials (wet and dry season) were carried out at the IHBT tea After removing the spent leaves, infusion was cooled to room tem- experimental farm at Banuri, Palampur (32N · 76E), India. A random perature and transferred to a separating funnel (500 ml). The pesticide was block design was used, each block containing 100 bushes (10 · 10) of partitioned (extracted) into 100 ml dichloromethane twice. The organic Camellia sinensis (L.) O. Kurtze. Each block was separated from one layer was separated and collected in a 250-ml beaker. The spent leaves another by leaving two untreated rows as guard rows to prevent pesticide were dried between the folds of filter paper and residues were extracted from spill over. Fenazaquin was sprayed at two rates 125 g AI/ha (rec- following similar method mentioned for made tea. ommended) and 250 g AI/ha (double the recommended) in four replica- tions with hand operated Knapsack sprayer using a recommended 2.5. Cleanup formulation volume of 400 1/ha. In control blocks only water was sprayed. About 2 kg of the green shoots (two leaves and a bud) was The extracts were concentrated to 5 ml under a gentle air stream and harvested from each replicate of treated and control plots and brought to transferred to a florisil column pre-washed with 50 ml of n-hexane to 598 V. Kumar et al. / Food and Chemical Toxicology 44 (2006) 596–600 remove the coextractives. The column was eluted with 20 ml n-hexane 2.8. Statistical analysis followed by 10 ml of n-hexane and ethyl acetate (99:1 v/v). The eluates were collected in a 50-ml beaker, evaporated to dryness The experimental data were subjected to statistical analysis using and finally reconstituted in 2 ml acetonitrile for final detection and Microsoft Excel program (Windows 2000). quantification. 3. Results 2.6. Detection and quantification Data on residue dissipation in green shoots, made tea, Quantification was accomplished by using a standard curve prepared by diluting the stock solution in acetonitrile. Good linearity was achieved transfer of residue in brew and spent leaves are presented between the range 0.1 and 1.0 lg/ml with a correlation coefficient of in Table 1. Initial residues deposits in green shoots at two 0.9998. The limit of detection was estimated to be 0.05 lg/ml of pesticide, rates, 125 and 250 g AI/ha, were 29.42, 56.57 mg/kg and based on signal to noise ratio 2:1. The column was conditioned by repe- 17.90, 33.37 mg/kg in the wet and dry seasons, respectively. ated injections (2–4) of standard and sample extracts until HPLC peaks In made tea, processed from the samples of green shoots were reproducible. Recoveries of the pesticide at different fortification levels, i.e. 0.5, 1, 2, 5 and 10 lg/ml were determined in five replicates from collected at different time intervals, initial residue deposits each matrix to validate and evaluate the accuracy of the method. were 58.94, 96.37 mg/kg and 31.19, 58.76 mg/kg during wet and dry seasons, respectively. At normal plucking 2.7. Calculation of percent transfer of residue round (seventh day after application of insecticides) 5.43– 7.37% and 6.18–7.31% of the residue (in wet season) and Percentage transfer of pesticide from made tea to brew ami spent 8.51–11.40% and 6.08–7.79% of the residue (in dry season) leaves were calculated by following formula: remained in green and made tea, respectively. No measur- C A able amount of fenazaquin residue was observed after 11th Transferð%Þ¼ S S 100; Cmt W mt day in either of the seasons. From the half-life value (Table 1), it is evident that the initial level of residue in green CS = pesticide concentration (mg/kg) in substrate (brew or spent leaves); shoots dropped by half in 34.32–40.80 h in the wet season AS = volume or weight (ml or g) of substrate, i.e. brew or spent leaves; while in the dry season it takes 50–52 h. Similarly half-lives Cmt = pesticide concentration in made tea (mg/kg); Wmt = weight of made in made tea were in the range 38.16–41.52 and 46–50 h in tea taken for infusion (g). As mentioned in Section 2.3, 5 g made tea was used to make brew in wet and dry seasons, respectively. This indicated faster res- 150 ml of boiling water. idue dissipation in the wet season then in the dry season.

Table 1 Fenazaquin residue in tea and its brewa Time interval (days) Residue (mg kg1) Green leaves Made tea Brew* Spent leaves Trt. 1 Trt. 2 Trt. 1 Trt. 2 Trt. 1 Trt. 2 Trt. 1 Trt. 2 Wet season 0 29.42 ± 2.08 56.57 ± 3.35 58.94 ± 2.12 96.37 ± 8.56 0.34 (17.27) 0.72 (22.40) 27.51 (46.67) 36.00 (37.36) 1 12.02 ± 0.74 20.83 ± 7.30 22.04 ± 5.52 31.48 ± 6.80 0.14 (19.38) 0.17 (16.42) 9.67 (43.90) 15.62 (49.63) 3 6.86 ± 0.42 10.91 ± 0.78 12.71 ± 0.88 16.06 ± 1.47 0.09 (20.46) 0.07 (12.45) 4.25 (33.47) 6.96 (43.35) 5 3.87 ± 0.39 5.58 ± 0.57 6.64 ± 1.59 10.54 ± 1.04 0.02 (7.53) 0.04 (10.44) 1.21 (18.27) 2.31 (21.95) 7 2.17 ± 0.56 3.07 ± 0.57 3.64 ± 0.31 7.04 ± 0.37 0.01 (8.25) 0.02 (8.52) 0.38 (10.54) 0.70 (9.90) 9 0.62 ± 0.19 1.08 ± 0.13 1.23 ± 0.04 1.91 ± 0.57 ND ND 0.12 (9.76) 0.21 (11.01) 11 0.02 ± 0.02 0.04 ± 0.04 0.00 ± 0.01 0.01 ± 0.01 ND ND ND ND 14 ND ND ND ND ND ND ND ND 21 ND ND ND ND ND ND ND ND t1/2 1.70 1.43 1.73 1.59 – – – – Dry season 0 17.90 ± 1.42 33.37 ± 2.54 31.19 ± 1.98 58.76 ± 2.03 0.153 (14.71) 0.337 (17.19) 12.76 (40.91) 24.70 (42.03) 1 10.83 ± 0.83 23.82 ± 1.52 16.84 ± 0.99 41.93 ± 1.62 0.060 (10.69) 0.207 (14.79) 8.78 (52.13) 17.49 (41.71) 3 7.19 ± 0.52 13.05 ± 0.54 10.59 ± 0.93 22.05 ± 1.03 0.030 (8.50) 0.087 (11.79) 4.42 (41.72) 7.11 (32.24) 5 4.36 ± 0.34 6.26 ± 0.25 5.77 ± 0.74 8.87 ± 0.80 0.013 (6.76) 0.020 (6.76) 2.42 (41.97) 3.38 (38.11) 7 2.02 ± 0.09 2.84 ± 0.17 2.43 ± 0.15 3.57 ± 0.23 ND 0.003 (2.80) 0.51 (21.02) 0.78 (21.83) 9 1.00 ± 0.11 1.34 ± 0.08 1.12 ± 0.04 1.34 ± 0.04 ND ND 0.04 (3.57) 0.21 (15.63) 11 0.23 ± 0.03 0.55 ± 0.08 0.26 ± 0.02 0.55 ± 0.03 ND ND ND 0.05 (9.04) 14 ND ND ND ND ND ND ND ND 21 ND ND ND ND ND ND ND ND t1/2 2.21 2.10 1.87 1.94 – – – – Trt. 1—treatment No. 1 (spray at 125 g AI/ha); Trt. 2—treatment No. 2 (spray at 250 g AI/ha); ND—not detected (limit of detection, 0.05 mg/ml); – not applicable; t1/2—half-life in days; values in parentheses: percent transfer of residues from made tea. a In untreated control samples sprayed only with water, at all time intervals, no residue of fenazaquin was detected. V. Kumar et al. / Food and Chemical Toxicology 44 (2006) 596–600 599

80 y = 0.0187x2 - 1.3524x + 66.928 Ghosh Hajara, 2000) might have played signiﬁcant role 2 70 R = 0.8387 and rendered fenazaquin residue unavailable in the short period of time in both wet (half-lives, 1.43–1.7 days) and 60 dry seasons (half-lives, 2.10–2.21 days). At normal pluck- 50 ing round (seventh day after treatment) at both the doses 40 P98% residues in wet season and P88% residues in dry 30 seasons disappeared in green shoots and made tea. This dif- 20 ference in disappearance of fenazaquin residues in tea in 10 diﬀerent seasons may be attributed lo the agro-climatic

Loss (%) of residue in made tea 0 conditions (Bhattacharya et al., 1995; Maniknandan 0 5 10 15 20 25 30 35 et al., 2001). The ether linkage between quinazoline and Conc. (mg/kg) of residue in green tea ethyl phenyl components of fenazaquin molecule is Fig. 2. Loss of fenazaquin residue during tea manufacturing. believed to be the most photo liable portion (Hatton et al., 1992). During dry periods the overexposure of sun- light might cause considerable degradation of fenazaquin y = -0.0013x2 + 0.2806x + 6.2838 25 residue in tea shoots. The growth dilution factor is impor- R2 = 0.9204 tant in reducing the residue levels in tea crop as the foliage 20 and the shoots on which pesticides are applied are in diﬀer- ent stages of growth. The weight of these immature shoots 15 increases over a period of 6–14 days, depending on the 10 plucking interval. The immature buds by the time attain the size of pluckable shoots; the residue of applied pesti- 5 cides on them will undergo a growth dilution. During pro-

Transfer (%) of residue in brew Transfer 0 cessing of green shoots, leaves are dried and decreased a 0 10203040506070weight by a factor of 3.33. Theoretically, residues in made Conc. (mg/kg) in made tea tea should be higher by the same factor but results show (Table 1) that the residue deposit in made tea is less Fig. 3. Transfer of fenazaquin residue in brew. (647%) than that of the value of theoretically calculated residue level. However, it is also evident (Fig. 2) that loss Considerable loss of residue was observed during the of residue in made tea increased with decrease in concen- processing of green shoots to made tea. The loss of residue tration of residues in green shoots. The present finding sup- decreases as residue concentration in made tea increases ports the studies reporting loss of many pesticides during (Fig. 2). During infusion only partial transfer (3–22%) of processing (Chen and Wan, 1988). The loss of pesticides fenazaquin in brew has been observed (Table 1). Transfer during processing might be due to three factors i.e. evapo- of residue increased with an increase in concentration of ration, degradation and codistillation (Cabras et al., 1998). residue in-made tea (Fig. 3). The maximum residue in brew The transfer rate of the pesticide residue in brew (0.72 mg/l) was detected in the 0 day sample (wet season) of depends on the water solubility (Wan et al., 1991; Nagay- made tea with 96.37 mg/kg residue deposit. No measurable ama, 1996), partition coefficient (Tsumura-Hasegawa residue was found in brew when made from the samples et al., 1992; Jaggi et al., 2001) and low vapour pressure harvested and processed after 7 and 5 days of treatment (Chen and Wan, 1988). Fenazaquin has low solubility in with recommended dose in wet and dry season, water (102 lg/l) but its fairly reasonable organic matter respectively. adsorption capability and partitioning coefficient The range of pesticide remaining with spent leaves was (Kow = 321,000) allows its transfer to brew in a consider- 3.57–52.13%. However, a relationship with made tea able proportion. residue concentration and seasonal variations was not Loss of fenazaquin in brew due to fugacity would be low observed. as the molecule has low vapour pressure (3.4 · 106 Pa at 25 C) as is solubility. However, the acidic nature of brew 4. Discussion may favour its rapid degradation (hydrolysis) at elevated temperature (Dow Elanco, 1993). Considerable loss of The rapid degradation of fenazaquin and its metabolites fenazaquin residue from brew may also be due to adsorp- in plants (citrus, pome and apple) has been reported (Dow tion to the organic component of the brew, i.e. leaves. Elanco, 1993). In tea field, besides the effect of some phys- The collective role of all these factors might be accountable ical and chemical factors like photo, thermal, pH and mois- for only partial transfer of residue in brew. The residue ture (Cosby et al., 1972; Miller and Zepp, 1983; Chen et al., remained on spent leaf did not show any trend. 1987; Agnihothrudu and Muraleedharan, 1990; Miller and It is evident (Table 1) that made tea processed from Donaldson, 1994), growth dilution factor (Chen and Wan, green shoots collected after the fifth day in either of the sea- 1988; Agnihothrudu and Muraleedharan, 1990; Bisen and sons are likely to have a residue level up to 3.64 mg/kg at 600 V. Kumar et al. / Food and Chemical Toxicology 44 (2006) 596–600 recommended dose. As tea is subjected to infusion prior to References consumption, it is the residue transferred in brew which actually contributes to the dietary intake. Considering a Agnihothrudu, V., Muraleedharan, N., 1990. Pesticide residues in tea. maximum of 10 cup of tea (150 ml per cup) consumption Planters Chronicle 85, 125–127. Bhattacharya, A., Chowdhury, A., Somchowdhury, A.K., Pallarl, A.K., by an individual, the actual intake of residue on the basis Roy, U.S., 1995. Studies on residues, persistence and pre-harvest of residue data in brew, is only 0.015 mg of fenazaquin interval of cythion, durmet and ripcord in made tea of Darjeeling. when brew is prepared from the made tea processed from Peslology 21 (2), 28–36. the samples treated at recommended rate and harvested Bisen, J.S., Ghosh Hajara, N., 2000. Persistence and degradation of some after 5 days of the treatment in either of the seasons. The insecticides in Darjeeling tea. Journal of Plantation Crop 28 (2), 123– 131. estimated intake with brew (maximum consumption of 10 Cabras, P., Angioni, A., Garau, V.L., Menelli, E.V., Cabitza, F., Pala, M., cup/day/adult) thus would be below the acceptable daily 1998. Pesticide residue in raisin processing. Journal of Agriculture and intake for fenazaquin (0.005 mg/kg-body weight). Food Chemistry 46, 1309–2311. The MRLs in tea in most of the cases are fixed on the Chen, Z.M., Wan, H.B., 1988. Factors affecting residues of pesticides in basis of pesticides residue present in made tea (European tea. Pesticide Science 23, 109–118. Chen, Z.M., Wan, H.B., Wang, Y., Xue, Y., Xia, H., 1987. Fate of Union, 2002). However, it is the actual residue of pesticides pesticides in the ecosystem of tea garden. In: Proceedings of the in brew that should be considered for setting up realistic International Symposium on Tea Quality-Human Health. Tea MRLs. Fenazaquin like many of the pesticides listed for Research Institute, Chinese Academy of Agriculture Sciences, Hangz- tea do not have yet firm limits assigned because of lack hou, China, pp. 146–149 (4–9 November). of data representing the actual residue contributing to the Cosby, P.G., Moilanon, K.W., Nakagawa, M., Wong, A.S., 1972. Environmental Toxicology of Pesticides. Academic Press, New York. dietary intake. Therefore, for the time being importing Dow Elanco, 1993. Fenazaquin—A Profile. Department of Regulatory countries are free to maintain or set their own tentative lim- Toxicology and Environmental Affairs, Agriculture Products Research its or to adopt stipulations fixed by an international orga- and Development, Oxfordshire, UK. nization such as Codex Alimenterious Commission, which European Union, 2002. Appendix I EU/German Maximum Residue sets standards for the World Health Organization and the Limits on Tea, Appendices, 16 December. Hatton, C.J., Babcock, J.M., Schoonover, J.R., Dripps, J.E., 1992. Food and Agricultural Organization of the United Nations Fenazaquin, a new acaricide/insecticide. In: Proceedings of the (Jaggi et al., 2001). In this context, data of the present International Cong. Ent., p. 535. research are very relevant and useful for setting up stan- Hollingworth, R.M., Ahammadsahip, K.I., Gadelhak, G.G., Mclughin, dards for pesticide safety limit considered in regulating J.L., 1992. Complex I of mitochondrial respiratory chain: a target for problems with consumption of tea and its global trade. pesticide development by both man and nature. In: Proceedings of the American Chemical Society, Abs. No. 156. Jaggi, S., Sood, C., Kumar, V., Ravindranath, S.D., Shanker, A., 2001. 5. Conclusion Leaching of pesticides in tea brew. Journal of Agriculture and Food Chemistry 49, 5479–5483. Tea is generally cultivated under identical agro-climatic Manikandan, K.N., Muraleedharan, N., Selvasundaram, R., 2001. conditions and for commercial cultivation the most com- Residues and persistence of chlorpyrifos in processed black tea. Journal of Plantation Crops 29 (3), 35–37. mon species of tea is C. sinensis. In the present experiment Miller, G.C., Donaldson, S.G., 1994. Factor affecting photolysis of the same species of tea cultivated under common agro- organic compounds on soils. In: Helz, G.R., Zepp, R.G., Crosby, D.G. climatic conditions was used. The results showed that (Eds.), Aquatic and Surface Photochemistry. Lewis Publishers, Boca fenazaquin residue in tea, prior to consumption in the form Raton, FL, pp. 97–109. of brew, dissipates at three stages: (1) in green shoots resi- Miller, G.C., Zepp, R.G., 1983. Extrapolating photolysis rate from the laboratory to the environment. Residue Review 85, 89–110. dues disappear after 11 days of treatment in both seasons; Muraleedharan, N., 1994. Pesticide residues in tea: problems and (2) during processing to made tea with no residues in the prospective. Planters Chronicle 9, 371–375. sample from 11 to 14 days of wet and dry seasons, respec- Nagayama, T., 1996. Behavior of residual organ phosphorus pesticides in tively and thus balancing the factors accountable for foodstuffs during leaching or cooking. Journal of Agriculture and increased concentration of residue deposits in made tea Food Chemistry 44, 2388–2393. Shanker, A., Jasrotia, P., Kumar, A., Jaggi, S., Kurnar, V., Sood, C., from green shoots; and (3) during infusion in brew with 2001. Bioefficacy of new milicide: fenazaquin. Pestology 25 (6), 57–60. residue free samples after 7 days in both the seasons, Solomon, M.G., Fitzgerald, J.D., Ridout, M.S., 1993. Fenazaquin, a respectively. The acceptable daily intake for fenazaquin is selective acaricide for use in IPM in the UK. Crop Protection 12, 255– 0.005 mg/kg body weight (Dow Elanco, 1993). As tea is 258. submitted to infusion/prior to consumption, a waiting per- Tsumura-Hasegawa, Y., Tonogai, Y., Nakamura, Y., Ito, T., 1992. Residues of post harvest application of pesticides in citrus fruits after iod for more than 5 days for both the seasons at the recom- storage and processing into lemon marmalade. Shokuhin Eisegaku mended rate (125 g AI/ha) may be suggested and Zasshi 33, 258–266. considered quite safe to avoid health hazards due to the Wan, H., Xia, H., Chen, Z., 1991. Extraction of pesticide residue in tea by toxic effect of residues in brew. Thus the present findings water during the infusion process. Food Additives and Contamina- are useful in monitoring the fenazaquin residue in tea. tions 8, 497–500.