Tomato Growing Center

Decontamination of pesticide residues in fruits and vegetables

Preferably, the samples used in transformation studies CCR must contain quantifiable field treated waste as close as possible to the MRL, so that measurable residues were obtained, and the transfer factors for various processed products can be determined. A transfer factor provides the relationship between the concentration of residues in processed commodities for the RAC. For example, if the waste concentration is 0.5 mg / kg of olives and 0.2 mg / kg in olive oil, the transfer factor is 0.2/0.5 = 0.4. A factor 1 (= concentration factor) indicates a concentration effect of treatment procedures. Increase of waste or increasing rates of application, reducing the period before harvest (PHI) or by removing the CAR with the active ingredient and its metabolites in vitro is not, in general, desirable. Doping is acceptable if waste can be demonstrated that the CAR includes only residues from the surface. However, in some cases, especially when the waste within the JRC are close to the threshold determination of treatment on the ground in exaggerated rates or shortened SISP is recommended to obtain sufficient residue levels for transformation studies.

The first step in the home or commercial processing of foods is food preparation using different methods such as mechanical removal of damaged or soiled or parts of plants, washing, peeling, peeling or hulling. This often leads to a significant reduction in the amount of pesticide residue remaining in the edible parts (Petersen et al. 1996; Celik et al. 1995; Schattenberg et al., 1996).

WASH

The washing procedures households are usually made in the operation or stagnant water at moderate temperatures. Detergents, chlorine or ozone can be added to wash water to improve the efficiency of the washing procedure (Ong et al., 1996). If necessary, several washing steps can be made accordingly.

The effects depend on physico-chemical pesticides, such as solubility in water, hydrolysis rate constant volatility and octanol-water partition coefficient (POW) in connection with the actual physical location of washing waste processes lead to the reduction of hydrophilic residues found in cultivated areas. In addition, the washing temperature and water type Household has an influence on the residue level. As noted by Holland et al. (1994), the hot wash and the addition of detergents are effective than washing in cold water. Wash with the gentle touch of the hand under the tap water for 1 min remove pesticide residues so significant (Barooah and Yein, 1996). Residues of pesticides and systemic lipophilic not significantly suppressed by washing.

Table (1) shows Examples of the effects of washing residues of different pesticides applied to fruits and vegetables.

PEELING

The outer leaves of vegetables often contain residues of pesticides applied during the growing season. Therefore, peeling or cutting procedures reduce levels of residues in leafy vegetables. Peeling roots, tubers and bulb vegetables with a knife is a common practice in the house. Many examples show that most of the concentration of residues in or on the skin. Peeling the CCR can remove more than 50% of residues of pesticides in the main. Therefore, elimination of the removal of the shell is almost complete waste, so that small leaves in the edible parts. This is particularly For large fruits that are not eaten with the peel, like bananas or citrus fruits. Reynolds (1996) showed that the peel and cut carrots reduced Waste chlorfenvinphos, pirimiphos-methyl, quinalphos triazophos lead to a transfer factor of 0.2. However, the commercial shell peeling process can be used for animal feed or for production of essential oils (citrus) or pectin (citrus, apple, etc.). For such industrial processes is important to realize that surface residues and certainly not systemic is often concentrated in the tank. For systemic pesticides, peeling, it can be as effective as demonstrated Sheikhorgan et al (1994). After applying cucumbers thiometon no reduction in the level of residues was could be detected in the peeled cucumbers.

Under Codex Alimentarius, as in other international standards, MRLs refer to fruit integers, which is appropriate to assess compliance with good agricultural practices. These MRLs are minor, however, to assess dietary exposure to pesticides from fresh fruits that have been peeled (Holland et al., 1994).

COOKING

Cooking procedures at different temperatures, the duration of the process, the quantity of water or food additives, and system type (open or closed) may have an impact on the level waste. Generally, waste is reduced during cooking by volatilization in open systems or closed systems by hydrolysis. In any case, the addition of diluted waste cooking liquid. Several studies have reported on the dissipation of pesticides on crops during cooking. In addition to the studies summarized in Table 1, the behavior of organophosphorus pesticides chlorfenvinphos, fenitrpothion, Isoxathion, methidathion and during prothiophos Cook was examined by Nagayama (1996) with green tea leaves, spinach and fruits. These pesticides have decreased during the cooking process for the boiling point. According to its solubility in water, pesticide translocation of certain raw materials in the cooking water. In addition, the pesticide remained in processed foods based on their octanol-water partition coefficient, which is an indicator of hydrophilic or lipophilic properties of the compound. In exceptional cases, the process of cooking may cause a degradation of pesticides, obtaining a reaction product of toxicological significance. For example, UDMH daminozide is degraded (1, 1-dimethylhydrazine), which is much more potent than the parent compound (Leparulo-Lofus et al., 1992). Another example is the formation of ETU (ethylene thiourea) of related interest to EBDC (ethylene bis dithiocarbamate) fungicides such as mancozeb, during the heating processes (Petersen et al., 1996).

Immersion in a chemical solution

Solution of sodium chloride is widely used to decontaminate pesticide residues, various fruits and vegetables. There are several studies to demonstrate the effectiveness of washing salt water to remove pesticides from crops. In this process, the sample of chopped fruit and vegetables are placed in a beaker with 5% solution of sodium chloride. 15 minutes after the samples plants rubs his hand gently on salt and water solution is decanted alt. Examples of the effect of treatment with saline in the levels of residues of different pesticides applied to plants have been presented in Table 1.

Kumar et al (2000) reported that immersion of green peppers, 2% salt solution for 10 minutes followed by washing with water is effective in facilitating the disposal of 32.56 and 84.21% corresponding to 0 and 5 days after spraying triazophos (700 g ai / ha), while acephate residues were taken to an area of 78.95% on the zero day. Following the same technique Kumar et al (2000) And66.93 observed 90.56% discount for 0 and 5 days after spraying cypermethrin in peppers.

Dip Transformation fruit NaCl, HCl, acetic acid, NaOH solution of potassium permanganate eliminates 50-60% of the surface residues of synthetic pyrethroids compared to 40-50% removal by hydrolytic degradation with NaOH (Awasthi, 1986b).

NaOH water solution, potassium dichromate, acid, acetic acid and a soap solution used as a decontamination agent for Tom … … … ….

Treatment of fruit with a decrease of 2% tamarind solution for 5 minutes followed by washing with tap water and steaming for 10 min. Has been found to eliminate residues of monocrotophos, carbaryl and fenvalerate in From 41.81, 100 and 100% respectively. Treatment with a solution of 2% salt was also effective.

Dip eggplant water treatments fruit wioth solution of sodium chloride HCl, a solution of acetic acid solution potassium permanganate were found to remove the residues of fenvalerate 30-33% permethrin, cypermethrin and deltamethrin; NaOH solution Teepol 40-45% (detergent) solution of 50-60%. The effect of washing on the reduction of waste has decreased gradually in the harvesting of second and third.

Many experiments have been conducted with the three common household willing to learn. washing with water, wash water salt and cook to assess their effectiveness in reducing pesticide residues in different plants. The results are summarized in the table below.

Table: Effect of cleaning, washing and cooking salt in the levels of pesticide residues.

% Cultures Reference pesticide residues expelled * Results

Wash

Salt Water Wash Water Kitchen

Cauliflower Methamidophos 41-48 46-47 46.94

-53.54 Further reduction was caused by cooking. Jacob and Verma (1990)

Okra

Methamidophos

64-72

19-58

58-64 water washing can remove the maximum residue that indicates its maximum solubility in water, although all processes below the values TMRL. Jacob and Verma (1990)

Cauliflower alpha-cypermethrin

_ 7-38

12-17 was more effective cleaning of the kitchen, probably due to the thermal stability of cypermethrin. Malik et al (1997)

Chou

Chlorpyrifos

Quinalphos

38

41

52.13

56.50

54.3

55 residues of three processes somewhat reduced. They can reduce residues below the MRL. Thus, a waiting period of a minimum of one and two weeks, it has been suggested, apart from washing and cooking on chlorpyrifos quinalphos cabbage. Nagesh and Verma (1997)

Cow peas

Metasystox

Carbalyl

84.3

87.5

86.4

88.7

83.4

Only 80.8 boiling samples sheath could decontaminate residue from the surface or within the tissues as far as safety limits by day 10 of treatment. Dikshit et al (1984)

Cauliflower

Malathion

60

70

Kitchen 80 was more effective and reduces TMRL the value of a week to zero days. Jacob and Verma (1989)

Bhindi

Quinalphos

61.84-64.35

43-53

78-82

The wash water and washing with salt water waste MRL below zero days in the kitchen to do the minimization of waste involved.

Jacob

Verma (1985)

Chou

Malathion

Carbaryl

Pyrethroids

64.60

75.40

22.06 (Av)

—

—

—

83.97

89.62

56.72 (Av)

The extent of decontamination was high because of the kitchen in relation to money all insecticides.

Bhatia and

Verma (1994)

The leaves and dotted with heads of cauliflower and the Indian Oilseed rape pods

Beans

Methamidophos

DDT

Malathion

Carbaryl

65.71-77.67

71

96

52

—

—

—

—

80-88.88

52 (cooked)

66 (pressure cooked)

99 (cooked)

99 (p.cooked)

77cooked

69 (p.cooked)

Highs of food waste dislodged.

Water washing removes the residues of DDT up during cooking is effective in removing residues of carbaryl and malathion.

Dikshit et al (1986)

Elkins et al (1968)

The table above may say that cooking is more effective in reducing residues of different plants various vegetables, although in some cases, washing with water was effective to reduce initial pesticide residues and found that with aging waste or with increasing sampling days during the treatment of the effect of washing is reduced to eliminate the toxic substance to the same extent as from samples taken immediately after spraying boiling or Cooking is deemed effective. One possible reason for the high percentage of disposal of toxic substances from samples taken immediately because most of the residue on the sample surface and therefore easily removed by simple washing observed by Dikshit et al (1984.86) Elkins et al (1968) Bhatia and Verma (1994) and Malik et al (1998). Over time the waste is migrating within deeper tissues or adhere strongly to the rough surface certain vegetables. On the other hand, washing can reduce waste at the level of safety from boiling.

There are few studies within three culinary process proved effective in reducing residues under the MRL value. According residues Jacob and Verma (1991) treated quinalphos in the cultivation of cauliflower has been reduced to a certain extent by the different processing workshop, such as washing and cooking. Nagesh and Verma (1997) felt that the ineffectiveness of the house for decontamination processes and treated cabbage may be due to strong adsorption properties quinalphos and chlorpyrifos.

Effect of household preparation for the decontamination of multi-pesticide residues in fruits and vegetables

Low levels of pesticide residues were detected in 97 (40%) samples tested after 243 meters go for normal washing, peeling and cooking procedures. The number of samples containing detectable residues has been reduced to 47 (19%) after preparing households. These results indicate that the level of residues in most commodities fell sharply after the preparation of the house (Schattenberg et al. 1996)

Ramesh and Balasubramanian (1999) conducted a study with fruit and vegetables collected from local markets of Chennai and fortified with known concentrations of various pesticides followed by a study of the decontamination of various household preparations such as washing, cooking, peel 65-95% resulting from the cleanup of pesticide residues in various stages of 512 samples analyzed market premium, organochlorine and organophosphorus pesticides found in 12 samples were withdrawn following residues well below the limits of acceptable toxicity.

Rinsing with tap water reduces pesticide residues short in many types of products (Krol et al., 2000). Flush waste eliminated nine of the twelve pesticides studied. Between captan, chlorothalonil, iprodione, vinclozolin, endosulfan, permethrin, methoxichlor, malathion, diazinon, chlorpyrifos, bifenthrin and DDE residues of vinclozolin, bifenthrin and chlorpyrifos were not removed. This study confirms that the water solubility of pesticides does not play an important role in the decline. Most waste pesticides seem to reside on the surface products that are eliminated by the mechanical action of washing.

Early studies on the effects of the preparation of commercial pesticide residues and household fruit and vegetables have been summarized by Zabik (1987). Early studies showed a reduction in waste for to be important with a percentage reduction of chlorinated hydrocarbons from 50 to 99% + range for the commercial preparation and from 14 to 99 +% for preparation at home, with the exception of parathion in spinach and broccoli, and organophosphate residues prewparation Home commercvial considerably reduces the overall decrease, being in the top 80 or 90%. Carbamate waste has been reduced from 58 to 99 +% when plants were treated commercially but only 11 to 92% on home preparation.

A recent Korean study supports these earlier studies (Lee and Lee, 1997). They found that 45% of organophosphate residues are removed when the food is washed with water, 56% with a detergent, 91% with peeling, and 51% with money.

Methods of multi-residue pesticide analysis in fruits and vegetables

Analysis by gas chromatography

Nakamura et al (1994) developed a method for multiresidue analysis of 48 pesticides (20 organophosphorus organochlorines, 7, 14 organonitrogen pyrethroid pesticides and 7) allows for Japan on the basis of capillary GC after extraction of pesticides samples nacetone vegetables and fruits or acetonitrile containing cultures of lipids followed by re-extraction with ethyl acetate (test solution). Organophosphorus pesticides were directly determined by GC-FPD. Organonitrogen pesticides were determined by GC-FTD (GC-NPD), after cleaned by chromatography on silica gel. Organochlorine pesticides and pyrethroids, have been measured by GC-ECD after cleaned by Florisil column chromatography. The recovery of ten crops in the enrichment of 0.05-0.25 ppm 42,5-128,5%. detection limits were 0.001 ppm for organophosphates and organochlorine pesticides and 0.01 ppm for organonitrogen and pyrethroid pesticides.

A method has been used by multi-residue Dejonckheere et al (1996) for the determination of organochlorine pesticides and organonitrogen organophosphorus pesticides in vegetables and fruits that have been extracted with acetone followed by liquid-liquid with water: pesticides in the ether oil apolar, polar extracted the aqueous layer with dichloromethane and analyzed by gas chromatography with electron capture (GC-ECD), flame photometry (GC-FPD) and thermionic specific (GC-TSD) detection.

The method used for the multiresidue determination of 52 pesticides, including compounds organophosphates, organochlorines, organonitrogen, pyrethroids and some dithiocarbamate pesticides in vegetables and fruits has been described by Dogheim et al (1999) by gas chromatography. Samples were extracted with acetone followed by partition with hexane and dichloromethane and estimated by GC-ECD and GC-NPD. Dithiocarbamates were digested in a mixture of concentrated HCl, SnCl2 and water for development of CS2, said in an alcoholic solution of copper acetate and diethanolamine to form a yellow complex. The absorbance of yellow product was determined by spectrophotometry at 435 nm. The mean recovery and CV of the 52 pesticides were 72-118 and 1-20%, respectively, over levels of 0.01-1 ppm. A similar method has also been described by Kole et al (1998).

Krol et al (2000) used a procedure in several residues for the determination of 12 pesticides in plants where the samples were extracted with 2 propanol and petroleum ether, followed by a washing with distilled water 3 times. The final analysis of samples was performed by GC-ECD, FPD, XSD and / or ELCD.

Ramesah and Balasubramanian (1999) describes a method of determining organochlorine and organophosphate pesticides organonitrogen in fruits and vegetables after extraction using 2-propanol and petroleum ether by mechanical shaker followed by partitioning of distilled water and Florisil column cleanup for organized crime and organophosphate pesticides. For pesticides organonitrogen extraction was performed with acetone followed partitioning with 10% NaCl and ethyl acetate and column cleanup on silica gel. organochlorines and organophosphates were organonitrogen analyzed by GC-ECD, GC-NPD and GC-FPD, respectively.

Using GC-ECD, the effectiveness of acetonitrile and acetone to extract the 8 pyrethroids 6 samples of fruits and vegetables were compared by Pang et al (1997). The extraction efficiency of acetone was competitive acetonitrile with samples of fruits and vegetables 6. Robustness tests also showed that the proposed method is simple, accurate with a good accuracy and suitable for multiresidue analysis of pyrethroid insecticides in various agricultural products.

Organophosphate and organochlorine pesticides waste from fruit and vegetables by capillary GC detector with electron capture (EDC), a nitrogen phosphorus detector (NPD), flame photometric detector (FPD) in sulfur and modes of phosphorus detector and mass spectrometry (MSD) in selected ion monitoring (SIM) mode have been determined by Thompson et al (1995) after extraction of the matrix solid phase dispersion (MSPD) after recovery of 41-108% with relative SD of 2-14% in conc. range 0.5-10 mg / liter in oranges, lemons, grapefruits, pears, plums, lettuce and tomatoes.

A multiresidue method described by Sannino et al (1995) for the quantitative determination of 39 organophosphorus compounds (parent pesticide and its metabolites major) in 7 of fatty foods processed from permeation chromatography with an automated gel SX3 column and Biobeads methylene chloride-cyclohexane (15 + 85) eluate after extraction with methylene chloride. The organophosphates were quantified by GC-FPD using OV-1701 and DB-5 columns. Average recovery of samples spiked at 0.025-1 mg / kg ranged from 50.6% to 185% for malaoxon dichlorvos. Determination limits were between 0.005 and 0.040 mug / ml. The results were confirmed by gas / mass spectrometry with ion chromatography of selected control.

Chromatographic conditions for gas separation and identification of compounds were selected using two polarities of capillary columns and two different detectors, ECD and NPD for multiresidue quantitative determination of 37 pesticides in fruits and vegetables, and to study the effectiveness the permeation chromatography gel after cleaning by extraction with ethyl acetate (Balinov, 1999).

Trova et al (1999) conducted by the determination of liquid chromatography for pesticide residues (including azinphos-ethyl, azinphos-methyl, carbaryl, diflubenzuron, teflubenzuron dinocap) in vegetables after extraction with ethyl acetate / n-hexane and the solvency of the system in place of methylene chloride are widely used. Recoveries as required by the guidelines for monitoring residues in the European Union where there was the solvency new system can be considered as an alternative to halogenated compounds, dangerous for their toxicity and harmful behavior in the environment in mining HPLC-active compounds determinable.

A wide range of detection method was proposed by Gelsomino et al (1997) for multiresidue analysis of 77 pesticides (12 organohalogen, 45 organonitrogens, 11 organophosphates and pyrethroids 9) in agricultural products by gas chromatography equipped with long, narrow canyon Fused silica open tubular columns and a detector of electron capture (EDC). The residues were extracted with acetone followed by dichloromethane and partition chromatography cleaning gel permeation. Recoveries of most pesticides in spiked samples of carrot, melon and tomato at fortification levels of 0.04-0.10 mg / kg 70-108%. The detection limits were below 0.01 mg / kg for early childhood.

Beena et al (2002, 2003) carried out an inspection of samples of vegetables adopting a technique multi-residue analysis using GC-ECD and GC-NPD systems with capillary columns.

Ueno et al (2003) studied an effective and reliable multiresidue to determine nitrogen and phosphorus-52-containing pesticide residues in many samples of vegetables in which the samples were extracted with acetonitrile and the acetonitrile layer separated was purified by permeation chromatography gel effluent is divided into 2 fractoions pesticides, pesticide fractions were respectively purified by a 2-step minicolumn cleanup, the fraction of seconds through a silica gel minicolumn; first fraction through the ether tandem minicolumn (florisil minicolumn inserted in mini column silica gel), which was eluted with acetone, petroleum (3 +7). The combined eluate was subjected to a double chromatography gas chromatography column with nitrogen-phosphorus and flame photometric detection. Recoveries of 52 pesticides in spiked samples ranged from 72 to 108% compared to the standard deviation of 2.17%, except for the recovery of methamidophos and chorothalonil. The detection limits of pesticides were satisfactory (0.001-0.009 mg / kg) for control of pesticide residues in vegetables.

Menkissoglu et al (2004) A study of the effects induced by the matrix the 16 common pesticides, surveys of more frequent monitoring in tomato pepper and cucumber, with a multiresidue method Simple GC-ECD or NPD, without a stage Previous cleaning. Abnormally high GC responses and then the high rates of return of several pesticides in the extracts were obtained through a conventional calibration with pesticide in the solution of ethyl acetate.

A faster, less efficient, friendly the environment of supercritical fluid extraction (SFE) method was evaluated by Garcia et al (1996) methods of extraction conventional extraction sonvent imidacloprid, methiocarb, chlorpyrifos, chlorothalonil, endosulfan-1, endosulfan-2 and sulphate endosulfan, pepper and tomato using mixtures of sample: sulfate magnesium chloride (5:7) to make the extraction supercritical CO2 and HPLC / DAD, GC / ECD and GC / FPD for analysis. The conditions were selected SFE 300 atm, 500C, 200? L of methanol modifier static, 1 minute time static and dynamic extraction with 15 ml of CO2 and collection in 3 ml of ethyl acetate. Except for imidacloprid, which has not found in any of the test conditions, pesticide recoveries were above 80%.

A simplified method is described by Chaput (1987) in liquid chromatography in reverse phase was used with post-column derivatization and fluorescence detection to determine 7 N-methyl carbamates (aldicarb, carbofuran and carbaryl, methiocarb, methomyl, oxamyl and propoxur) and 3 metabolites in fruits and vegetables after extraction sample with methanol followed by chromatography, gel permeation (GPC) or GPC with online cleaning nuclear crops Celite to chlorophyll high and / or content of carotene (eg, cabbage and broccoli). Recovery data were obtained by fortifying 5 different cultures (apples, broccoli, cabbage, cauliflower and potatoes) at 0.05 and 0.5 ppm. Recoveries averaged 93% at both spiking levels. The coefficient of variation of method with two levels is
Makoto et al (1994) studied the multi-residue procedure of 10 organophosphate pesticides to establish methods Analysis by gas chromatography capillary column with flame photometric (FPD) and spectrometric detection (GC-MS mass). Gas chromatography Quantitative with FPD was examined to determine the conditions for multi-column chromatography GC. Gas chromatography GC-MS was studied to select the fragment ions suitable for the determination and identification.

Estimated GC-MS/LC-MS

Due to the mass spectrometer is capable of achieving higher levels of molecular specificity in comparison with GC detectors and can be programmed to search hundreds of ions stations, GC / MS is a promising method for exploring the regulatory bodies for monitoring pesticide residues in foods of daily consumption (Cheng et al, 1994).

Cheng et al (1994) reported a multiresidue method by gas chromatography / mass spectrometry / Selected ion monitoring (GC / MS / SIM) for the determination of captan, chlorothalonil, dichlorvos, dimethoate, EPN, phorate, pirimiphos-methyl prothiophos waste fruits and vegetables. Recoveries were between 46 and 108% at 0.5 mg / kg fortification levels for each pesticide in apples, cabbages, cucumbers and grapes. The coefficients of variation ranged between 0.7 and 19%, with an average of 7.5%. The estimated detection limits of pesticides on crops were 0.1-0.05 mg / kg, except that the detection limit was entered in the cultures of more than 0.5 mg / kg.

A method based on solid phase extraction carbograph with 1 cartridge and reverse phase liquid chromatography mass spectrometry (LC / MS) electrospray (ES), the interface has been described by Corcia et al (1996) to measure traces of N-methylcarbamate insecticides in 10 different types of fruits and vegetables. Twelve carbamates added to plant material were extracted with methanol using a homogenizer followed by filtration, an aliquot of homogenate equivalent 5 g plant material was suitably diluted with water and passed through January 1 Carbograpg 1 extraction cartridge. Carbamates were eluted through cartridge 6 ml CH2Cl2/CH3OH (80:20 v / vegetables) of the mixture. The recovery of analytes is greater than 80%, irrespective the array of vegetables in which analytes were added.

A fully automated method by solid phase extraction (SPE online) the Cleaning samples and analyzing liquid chromatography with UV fluorescence detection and tandem for the determination of carbendazim and thiabendazole in different cultures has been reported by Hiemstra et al (1995).

A total of 199 pesticides were determined by Fillion et al (1995) in fruits and vegetables by using acetonitrile as solvent and coal mining mini-Celite column cleanup followed by gas chromatography with mass selective detection mode selective ion monitoring. Carbamates were analyzed by liquid chromatography with post-column reaction and fluorescence detection. Recovery data were obtained through the enrichment of 3 matrices (pear, carrots and bananas) at 0.1-0.5 ppm.

Blasco et al (2004) uses a quantitative dispersion matrix solid phase and liquid chromatography and mass spectrometry ionization atmospheric pressure chemical (APCI-LC-MS) method for the simultaneous analysis of dithiocarbamates and their degradation products in crops. Recovery average ranged from 33 to 109%, and the relative standard deviation ranged between 4 and 21%, with limits of quantification ranged from 0.25 to 2.5 mg / kg.

A multi-residue analysis for the determination of 101 pesticides, including organophosphates, organochlorines and pesticides containing nitrogen crops by gas chromatography with mass selective detection was made by Chun et al (2003). The analysis was conducted mode selected ion monitoring. The samples were spiked with pesticides at 0.1-1.0 mg / kg. Recoveries of 90% of pesticides in the morning between 70 and 110%, however, recovery of acephate and folpet were very poor, ie
An analysis of high performance of multi-pesticide residues is a single extraction with ethyl acetate and one column cartridge (consisting of two layers of water polymers absorbent (top) and carbon graphite (bottom)) the cleaning procedure in non-fatty vegetables and fruits has been developed by Obana et al (2001). In a recovery test, 110 pesticides were off and the average recovery was over 95% of spinach and orange. Most pesticides were found in the range of 70-115% with relative standard deviation generally
One method of analyzing simultaneous and consecutive waste pesticides in a large number of food samples by extraction with acetonitrile, followed by permeation chromatography gel (GPC) and the cleaning cartridge mini-column and double-column GC equipped with ECD has been studied by Ueno et al (2004). Recoveries of 58 pesticides from fortified spinach, tomatoes, apples and strawberries are very good (70-121%) except acrinathrin, captan, captafol, dichlofluanid and etridiazole (
The simultaneous determination of 251 pesticide residues and degradation products of samples of fruits and vegetables by gas chromatography with mass selective detection in the selected control mode of ion and liquid chromatography with post-column reaction and detection fluorescence of N-methyl carbamate after extraction of acetonitrile and octadecyl (C18) solid-phase cartridge and cleaning, cleaning, in a second, through a carbon cartridge coupled to an amino propyl cartridge has been described by Fillion et al (2004). Limits the scope of detection between 0.02 and 1.0 mg / kg for most compounds. Over 80% of the compounds have a detection limit _0.04 mg / kg.

Aguera et al (2002) used gas chromatography using a combination of positive chemical ionization (PCI) and electron impact (EI) ionization modes and mass spectrometry in tandem (GC-PCI/EI-MS-MS) as a method of analysis to determine 55 organochlorine compounds and organophosphorus and pyrethroids used in crop protection. Pesticide residues were extracted from samples with a mixture of acetate ethyl sodium sulphate to a final concentration before the sample of 1 mg / ml extract. No additional cleaning was action. Good sensitivity and selectivity of the method were obtained with detection limits ranging from 0.07 to 4.21 mg / kg all cases, except for methamidophos, permethrin, cypermethrin and difenconazol [difenoconazole]. Recoveries averaged between 52 and 114% were obtained and good linearity was observed in the ranges studied (r_0.994).

Multiresidue A simple, rapid and sensitive for the determination of ten organophosphorus and organochlorine pesticides using a miniature extraction with ethyl acetate followed by large volume injection (10 mL) GC-EI-MS analysis in SIM (selective ion monitoring) mode was developed by Aguera et al (2004). The sensitivity and selectivity of the method were acceptable with limits of detection (LOD) of less than 0.01 mg kg-1 with the exception of endosulfan-alpha and beta (0.05 mg / kg). The mean recovery between 63-99% were obtained and good linearity was observed in the range 0.01 to 1.00 kilograms mg 1.Repeatability and reproducibility studies gave relative standard deviations below 20% in all cases. The method has been applied to the analysis of 110 samples of vegetables, under the monitoring program of the Association of Producers and Exporters of Fruits and Vegetables Almeria.

A pesticide multiresidue method that allows analysis, quantitative and collation of a large number of samples fruit and vegetables by gas chromatography / mass spectrometry was reported by Ueno et al (2004). The sample is extracted with acetonitrile and the extract was cleaned by a salting step followed by redissolution in ethyl acetate. Co-extraction automatically deleted chromatography gel permeation column with a carbon graphite, followed by a column in tandem silica-gel/PSA cartridge. Recoveries of 82 of the 89 pesticides of spinach fortified, tomato, apple, strawberry and were within the range 70% to 120, and values on the standard deviation of 80 of the 89 pesticides
Analysis of the methanol extract without other cleaning measures was performed by liquid chromatography-electrospray ionization tandem mode mass spectrometry, which combines positive and negative ions for the determination of a group of 16 pesticides most commonly used multiclass Crop Protection. The extraction step was performed with a mixture of ethyl acetate and sodium sulfate presence of 6.5 M NaOH. The average recovery obtained were between 70 and 110% in most cases with an accuracy of
A new method analysis by liquid chromatography-mass spectrometry in tandem for the routine analysis of 31 multi-residue pesticide class and apply about 50 samples of fruits and vegetables (green beans, cucumber, pepper, tomato, eggplant, watermelon, melon and zucchini) was developed by Garrido et al (2004). Extraction of pesticides with ethyl acetate is out. The mean recovery obtained for each pesticide ranged cucumber between 74 and 105% in two different levels of enrichment (n = 10 each) that ranged between 9 and 250 ng g -1 (depending on product). The uncertainty associated with the method of analysis was less than 23% for all compounds tested. The limits of detection and quantification calculated were generally

Proposed work plan

Standardization of methods multi-residue analysis of pesticides

Standard analysis of certain pesticides belonging namely, the different classes. OC (HCH (?,?,? Y? Isomer), DDT (OP-DDT, pp-DDT, op-DDD pp-DDE), endosulfan ( "," Y endosulfan sulfate) and dicofol), OP (Dimethoate, malathion, parathion-methyl, chlorpyrifos, Quinalphos, Triazophos phosphamidon Metasystox dichlorvos and monocrotophos) and synthetic pyrethroids (cypermethrin, deltamethrin, fenvalerate) in monitoring and decontamination studies were collected from various sources as follows:

No. Name of the pesticide Sl% purity Source

Organochlorines

1?-HCH 99.5 EPA

2?-HCH 99.5 EPA

3'-HCH 99.5 EPA

4?-HCH 99.5 EPA

5 OP-DDT 99.7 EPA

6 PP-DDT 99.7 EPA

7 op-DDD 99.7 EPA

8 PP-DDE 99.7 EPA

9?-Endosulfan 99.0 Excel

10?-Endosulfan 99.0 Excel

11 endosulfan sulfate Excel 99.0

Bayer 12 Dicofol 96.0

Organophosphates

Dimethoate 13 UPL 96.5

Malathion 14 UPL 97.3

Bayer 15 of methyl parathion 98.5

99.7 Chlorpyrifos 16 Crop Protection Ltd Denocil

Sandoz Ltd 17 Quinalphos 95.6

18 Phosphamidon 93.9 Bayer

40.8 Triazophos 19 Aventis Crop Science

Monocrotophos 20 UPL 77.0

Dichlorvos 21 —

22 Metasystox —

Synthetis pyrethroids CCSRI

Cypermethrin, 99.0 CCSRI

Deltamethrin

Fenvalerate 99.0

99.0 CCSRI

4.1.1 Stock Solution Reason: stock standard solution of various pesticides must be prepared in distilled hexane / acetone and diluted appropriately to serve as standard work and mindividual chromatographic peaks verify their suitability for multi-residue analysis.

4.1.2 Preparation of standard solytion mixed: the individual standard solutions of mixed standard solution was prepared for method mdevelopment and studies on decontamination.

4.1.3 Extraction and cleanup

From a literature review three methods proposed by Kole et al (1998), Nakamura et al (1994) and Obana et al (2001) were chosen to perform the extraction and cleaning procedure that both the liquid column liquid and solid phase extraction with a game against the cartridge development in a fast, easy and cost effective method for detecting a wide range of pesticides.

4.1.4 Estimation of multi-residue pesticide

A gas chromatograph coupled to a detector for electron capture (EDC) and a nitrogen phosphorus detector (NPD) will be used to estimate pesticide residues. The operating conditions, also be studied, as shown in the three methods chosen.

4.1.5 Standardization of Mathod:

The method selected for Wil normalized by performing a study of recovery with the standard mixed by nailing in fruits and vegetables.

4.2 Monitoring of Pesticide Residues:

4.2.1 Sampling Program:

Typa Sampled fruits (mango and banana) and vegetables (tomatoes, peppers, Caulioflower, cabbage).

Place of sampling: From 2 wholesale markets renowned as … … .. West Bengal.

Frequency and duration of sampling: monthly for one year.

Sample volume: 1 kg of each sample.

4.2.2 Control of pesticide residues: All pesticides listed Table 2.

4.3 DECONTAMINATION studies

Pesticides should be selected on the basis of their largest employer in the World Bank use AS] selected pesticides follows: OC (?-endosulfan? endosulfan sulfate, endosulfan, dicofol OP: chlorpyrifos, Quinalphos, dimethoate, malathion triazophos, parathion-methyl, phos, monocrotophos, metasystix; synthetic pyrethroids: cypermethrin, deltamethrin and fenvalerate.

4.3.1 Decontamination procedures must be followed:

4.3.1.1 Washing in water samples taken ground in a tank containing water and the material is rubbed gently with water for a minute and the water is decanted and rinsed with water tap water for 130 sec. with rotating gently by hand. Washing is repeated twice or thrice.

4.3.1.2 Salt water wash, the samples of minced immersed in a beaker containing 2 or 55% solution of sodium chloride. After 10-15 minutes the plant samplws rubs his hand gently in a solution of salt and water salt is decanted. Then the samples were washed in water.

4.3.1.3 Boiling / Cooking: Wil dirty samples be cut and boiled in a beaker until the water is completely covering the CONTAINR evaporated with or without lids. Samples were allowed to cool.

4.3.1.4 Combination of above methods, including soaking in water for 15 min., Rinse with water, cut into pieces and boiled in water

4.3.1.5 washing with soap solution, rinse with water.

About the Author

Md. Wasim Aktar is a Senior Research Fellow in Export Testing Laboratory, APEDA, Govt. of India, under Deptt of Agricultural Chemicals, Bidhan Chandra Krishi Viswavidyalaya, Mohanpur, Nadia, West Bengal, India

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