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    WHO Pesticide Residues Series, No. 1

    1971 EVALUATIONS OF SOME PESTICIDE RESIDUES IN FOOD

    THE MONOGRAPHS

    The evaluations contained in these monographs were prepared by the
    Joint Meeting of the FAO Working Party of Experts on Pesticide
    Residues and the WHO Expert Committee on Pesticide Residues that met
    in Geneva from 22 to 29 November 1971.1

    World Health Organization

    Geneva

    1972

                     
    1 Pesticide Residues in Food: Report of the 1971 Joint Meeting of
    the FAO Working Party of Experts on Pesticide Residues and the WHO
    Expert Committee on Pesticide Residues, Wld Hlth Org. techn. Rep.
    Ser., No. 502; FAO Agricultural Studies, 1972, No. 88.

    These monographs are also issued by the Food and Agriculture
    Organization of the United Nations, Rome, as document AGP-1971/M/9/1.

    FAO and WHO 1972


    ENDOSULFAN

    Since the previous evaluations (FAO/WHO, 1968, 1969), additional data
    has become available and is summarized and discussed in the following
    monograph addendum.

    RESIDUES IN FOOD AND THEIR EVALUATION

    Residues resulting from supervised trials

    Recently-acquired data on residues of endosulfans A and B and
    endosulfan sulfate (TS) in lettuce, cauliflower, and cabbage are
    summarized in Table I. Endosulfan sulfate comprised 25-30% of the
    total residue on lettuce and 25-50% of the total residue on cabbage.
    Endosulfan B appears somewhat more persistent than A, sometimes
    accounting for more than 50% of the total residue. Although the data
    were somewhat erratic there was no indication of a build-up of
    endosulfan sulfate in excess of the temporary tolerance of 2.0 ppm
    (total residues) previously established by FAO/WHO (1969).

    A summary of the results of field trials conducted by Hoechst at two
    tea growing regions in India to determine residues in green tea, dry
    manufactured tea, and aqueous tea infusions is given in Table III
    (American Hoechst Corp., documents used in Food Additive Petition,
    Thiodan on Tea, 12 August, 1971). Application rates of 0.5, 1, and 2
    times the recommended rate of 2.5 litres of 35% E.C./hectare were
    used, and residues of endosulfans A, B, and sulfate were determined
    separately. The results show that total residues in dry tea leaves are
    lower in samples grown in low elevations. The residues are only
    slightly extracted from tea by hot water, yielding infusions
    containing only a few micrograms per litre.

    Endosulfan was applied to rice growing in the Philippines at 20 kg/ha
    of 5% granular (three applications) and 2 1/ha of 35% EC (three
    applications and four applications). Results of analysis for
    endosulfans A and B and endosulfan sulfate in rice (peeled and
    unpeeled), rice hulls, and rice straw harvested at two appropriate
    intervals are presented in Table II (Hoechst, 1971).

    FATE OF RESIDUES

    In animals

    Two dairy cows were fed endosulfan at 0.5 mg/kg body-weight daily
    (12.5 mg/kg was attempted but resulted in the death of one cow), but
    after two weeks the concentration in the milk was minimal and the dose
    was increased to 1 mg/kg for two weeks more. The milk collected from
    these two cows was manufactured into the dairy products, pasteurized
    milk, cream, butter, spray-dried whole milk, condensed whole milk,
    Cheddar cheese, and sterilized condensed milk and the by-products,
    skim milk, buttermilk, and cheese whey. Analyses of the products
    indicated only a very small concentration of endosulfan A. Endosulfan

        TABLE 1. SUMMARY OF FIELD RESIDUE DATA FOR ENDOSULFAN (HOECHST PAPERS)
                                                                                      
                   Total dose      Days following              Residue, ppma
                   active               last
                   ingredient        application      A        B        TS      Total
                                                                                      
    Lettuce        2.5 kg/ha              9           0.3      0.3      0.2     0.8
                                         30           0.2      0.2      0.2     0.6
                                         32                                     <0.05
                                         43           0.2      0.1      0.1     0.4

                   0.02 kg/ha            20                                     1.17
                                         28                                     0.335
                                         35                                     0.096
                                         42                                     0.000

    Cauliflower    0.0525 g/plant         7           0.034    0.036    n.d.    0.07
                                         14           0.020    0.024    n.d.    0.04

    Cabbage        0.75 kg/ha             7                                     n.d.
                                         14                                     n.d.

                   0.45 kg/hab           12           0.04     0.08     0.04    0.16
                                         22           0.05     0.16     0.12    0.33

                   0.90 kg/ha            12           0.26     0.56     0.17    0.99

                                         22           0.07     0.27     0.15    0.49

                   0.36 kg/ha             7           0.35     0.70     0.40    1.45
                                         14           0.15     0.17     0.31    0.63
                                         21           0.02     0.23     0.39    0.64

                   0.72 kg/ha             9           0.40     0.69     0.35    1.44
                                         14           0.71     0.91     0.39    2.01
                                         21           0.21     0.52     0.70    1.43
                                                                                      
    a A = Endosulfan A (alpha); B = Endosulfan B (beta); TS = Endosulfan sulfate;
    n.d. = none detected.

    b Calculated from dosages of 35% E.C. reported in fluid oz./ acre using the factors
    1.745 g/cc. and 29.57 cc./fl.oz.


    TABLE II. ENDOSULFAN RESIDUES IN RICE AND RICE STRAW FROM THE PHILIPPINES
                                                                                      
    Application        Commodity         Date of              Residues in ppma
    rate                                 harvest     A        B        TS       Total
                                                                                      
    5% granularb       peeled rice       5.2.71      nn       nn       nn       nn
    (20 kg/ha)                           24.2.71     nn       nn       nn       nn

    TABLE II. (Continued)
                                                                                      
    Application        Commodity         Date of              Residues in ppma
    rate                                 harvest     A        B        TS       Total
                                                                                      
    3 applications     unpeeled rice     5.2.71      nn       nn       nn       nn
                                         24.2.71     nn       nn       0.06     0.06

                       rice hulls        5.2.71      nn       nn       0.04     0.04
                       rice straw        5.2.71      nn       nn       nn       nn
                                         24.2.71     0.30     0.83     1.82     2.95

    35% ECc            peeled rice       5.2.71      nn       nn       nn       nn
    (2 1/ha)                             24.2.71     nn       nn       nn       nn

    3 applications     unpeeled rice     5.2.71      nn       nn       nn       nn
                                         24.2.71     nn       nn       nn       nn

                       rice hulls        5.2.71      0.47     0.61     0.66     1.71
                                         24.2.71     nn       nn       nn       nn

                       rice straw        5.2.71      0.07     0.17     0.19     0.43
                                         24.2.71     0.10     0.34     0.44     0.88

    35% ECc            peeled rice       5.2.71      nn       nn       nn       nn
    (2 1/ha)                             24.2.71     0.02     nn       nn       0.02

    4 applications     unpeeled rice     5.2.71      nn       nn       0.06     0.06
                                         24.2.71     nn       nn       nn       nn

                       rice hulls        24.2.71     nn       nn       nn       nn

                       rice straw        5.2.71      0.21     0.29     1.11     2.21
                                         24.2.71     0.04     0.30     0.51     0.85
                                                                                      
    a A = Endosulfan A; B = Endosulfan B; TS = Endosulfan sulfate; nn = none detected.
    b Granular, last treatment date, 7 January 1971.
    c EC = emulsifiable concentrate, last treatment date, 27 January 1971.
    
    sulfate, which should have been the major residue present, was not
    determined (Li et al. 1970).

    In plants

    Shuttleworth et al. (1971) studied the effects of sugar beet
    processing to determine if endosulfan or endosulfan sulfate residues
    in sugar beet roots would concentrate in the processed beet pulp.
    Mature sugar beet root samples from a plot treated with three aerial
    applications of Thiodan 2 EC at 1.0 lb active/acre were analysed 0 and
    35 days after the last application. No endosulfan or endosulfan
    sulfate residues were found at the limit of sensitivity of the method
    of 0.05 ppm. Sugar beet pulp, obtained from processing the above


        TABLE III. ENDOSULFAN RESIDUES IN TEA AND TEA INFUSION
                                                                                                                          

    Rate           Pre-harvest                                      Maximum residues, ppm
    l/ha           interval, days               Dry manufactured teaa                       Tea infusiona
                                      A         B         TS        Totald      A           B           TS          Totald
                                                                                                                          
    2.5()         1                  5.0       15        5.6       25.6        0.0034      0.020       0.0070      0.0299
                   2                  2.8       9.6       5.9       18.1        0.0014      0.0083      0.0095      0.0168
                   4                  1.4       3.3       4.3       8.4         0.00086     0.0020      0.0036      0.0065
                   7                  2.4       0.8       1.0       4.2         0.00043     0.00027     0.0012      0.0019

    5.0(2)        1                  2.6       73        11        108         0.0095      0.093       0.0085      0.1110
                   2                  6.5       27        9.2       43          0.0018      0.023       0.0070      0.0317
                   4                  1.0       4.4       3.6       9.0         0.0061      0.0050      0.0045      0.0156
                   7                  0.25      0.7       1.4       2.3         0.00032     0.00030     0.0015      0.0019
                                                                                                                          
    (From 5000 ft elevation)                    Dry green teaa                              Green tea infusionb
                                                                                                                          
    1.25(1/2)     1                  12        20        6.1       38          0.007       0.014       0.020       0.041
                   7                  2.9       12        9.2       24
                   15                 n.d.      0.5       3.4       3.9

    2.50()        1                  19        25        10        50          0.024       0.052       0.025       0.101
                   7                  1.7       4.7       7.2       14
                   15                 0.9       2.4       2.6       5.3

    (From 3000 ft elevation)

    1.25(1/2)     1                  1.4       2.2       0.6       4.2         0.004       0.01        n.d.        0.014
                   7                  n.d.      0.9       4.0       4.9         n.d.        0.003       n.d.        0.003
                   15                 n.d.      n.d.      0.8       0.8         n.d.        n.d.        n.d.        n.d.

    2.50()        1                  4.8       13        4.6       18          n.d         0.002       0.011       0.013
                   7                  0.3       1.6       3.8       4.7         0.001       0.004       0.011       0.016
                   15                 n.d.      n.d.      0.8       0.8         n.d.        n.d.        0.006       0.006

    TABLE III (Continued)
                                                                                                                          
    Rate           Pre-harvest                                      Maximum residues, ppm
    l/ha           interval, days               Dry manufactured teaa                       Tea infusiona
                                      A         B         TS        Totald      A           B           TS          Totald
                                                                                                                          
    (From 5000 ft elevation                     Dry manufactured tea                        Tea infusion
                                                                                                                          

    1.25(1/2)     1                  10        20        6.4       36          0.011       0.045       0.030       0.086
                   7                  0.7       4.1       7.9       13
                   15                 0.1       0.3       2.9       3.3

    2.5()         1                  28        45        11        84          0.031       0.055       0.021       0.107
                   7                  2.2       6.1       6.5       15
                   15                 0.6       2.0       7.3       9.9

    (From 3000 ft elevation)

    1.25(1/2)     1                  3.4       9.8       2.4       16          0.007       0.024       0.012       0.043
                   7                  1.3       9.0       5.8       16
                   15                 n.d.      0.3       1.4       1.6

    2.50()        1                  10        16        3.6       30
                   7                  5.4       22        7.6       35          0.001       0.004       0.009       0.014
                   15                 1.4       3.8       6 2       11
                                                                                                                          
    a Three replications.
    b Two replications.
    c One sample only.
    d A = Endosulfan A, B = Endosulfan B, TS = Endosulfan sulfate.
    Total = maximum total of the replications, not necessarily the sum of the preceding A, B and TS columns.
    

    beets, was analysed and no residues of endosulfan or endosulfan
    sulfate were found at a sensitivity limit of 0.1 ppm.

    Thiodan 2 EC was applied to cotton by aerial spraying at 1.0 and 3.0
    (excess) lb active/acre/application for five applications each and
    both plots were harvested nine days after the final application. The
    cotton was ginned and the seed processed into meal, oil, etc. Residues
    found in the various processed products are summarized in Table IV.
    Overall recoveries were 90% for endosulfans A and B and 73% for
    endosulfan sulfate. However, a material balance of 96.2% was achieved
    for the 3 lb rate whereas a balance of only 60.5% was obtained for the
    1 lb rate (Hinstridge, 1969).

    TABLE IV. ENDOSULFAN RESIDUES IN COTTON PRODUCTS.
    ALL PLOTS RECEIVED FIVE APPLICATIONS AND WERE HARVESTED NINE DAYS
    AFTER FINAL APPLICATION
                                                                      
    Product            Rate              Maximum residues, ppm
                     lb a.i.        Endosulfan      Sulfate      Total
                     /acre/appl.    A and B
                                                                      
    Ginned seeda     1              0.20            0.05         0.25
                     3              0.80            0.36         1.16

    Linters          1              0.29            n.d.         0.29
                     3              2.8             n.d.         2.8

    Linter motes     1              2.4             1.19         3.6
                     3              15.2            4.2          19.5

    Hullsa           1              0.04            n.d.         0.04
                     3              1.00            0.10         1.10

    Meala            1              0.04            n.d.         0.04
                     3              n.d.            n.d.         n.d.

    Crude oil        1              0.13            0.03         0.16
                     3              0.24            0.04         0.28

    Refined oil      1              n.d.            n.d.         n.d.
                     3              0.14            0.03         0.17

    Soap stock       1              0.02            n.d.         0.02
                     3              0.06            n.d.         0.06
                                                                      

    a Maximum of four replications; all others are maximum of two
      replications except soap stock, one replication.


    Evidence of residues in food in commerce or at consumption

    Endosulfan residues were determined in a total diet sample collected
    in the Federal Republic of Germany. Food samples were collected in a
    supermarket in the Frankfurt area in accord with directions published
    by FAO/WHO and subjected to cooking or other normal home processing
    operations preparatory to consumption. No residues of endosulfan A or
    B or endosulfan sulfate were detectable in the food at analytical
    sensitivity limits of <0.001 ppm for food groups I-V and VIII-IX and
    <0,005 ppm for food groups VI and VII (Hoechst Report No. 95/68,
    29 October 1968).

    The results of total diet studies in the United States for the periods
    June 1967 - April 1968 and June 1968 - April 1969 were reported by
    Corneliussen (1969, 1970). Endosulfan (total) was found in three of
    the 360 composites in the 1967-1968 survey; once in leafy vegetables
    at 0.014 ppm, once in garden fruits at 0.008 ppm, and once in oils,
    fats, and shortening at 0.134 ppm. In the 1968-1969 survey, endosulfan
    was found in 16 of the 360 composites. Eight composites of leafy 
    vegetables contained total endosulfan residues ranging from a trace 
    to 0.042 ppm (average 0.012 ppm). Two composites of potatoes 
    contained residues of endosulfan sulfate of 0.004 and 0.011 ppm. Four 
    composites of garden fruits contained total endosulfan residues 
    ranging from a trace to 0.007 ppm (average 0.002 ppm) and two 
    composites of fruits contained 0.002 and 0.010 PPM. Processing of 
    leafy vegetables by a dietician resulted in a retention of 55% of 
    total endosulfan residues.

    The calculated daily intake of total endosulfan residues in the United
    States of America for the period June 1966 to April 1968 has been
    given by Duggan (1969) as a trace in each of the three categories
    - leafy vegetables, garden fruits, and oils, fats, and shortening.

    METHODS OF RESIDUE ANALYSIS

    No interlaboratory collaborative study of a multidetection method of
    analysis as applied to endosulfan has been published since the last
    re-evaluation. However, an analytical method for determining
    endosulfan A and B isomers and endosulfan sulfate residues in and on
    vegetable material has been developed by Hoechst (1966). The method
    differs from most multidetection schemes in that the crushed sample is
    extracted cold with a mixture of benzene and isopropanal (2:1). The
    isopropanol is separated by shaking the mixture with a 2% sodium
    chloride solution and the endosulfans remaining in the benzene phase
    are determined by gas chromatography with a microcoulometer or
    electron capture detector. If necessary, further clean-up may be
    achieved by (a) treatment of the benzene extract with attapulgite
    clay/carbon; (b) acetonitrile/hexane partitioning; or (c) by means of
    thin layer chromatography. The recovery of the method is generally
    80%  10% unless TLC has been used in which case it may fall to 70%.
    The limit of detection in favourable cases is 0.002 mg/kg.

    Samples containing high sugar contents (up to 20%) such as sugar beet
    roots and sugar beet pulp may give erroneously high recoveries if
    acetonitrile/water extraction Procedures are used. In these cases a
    method developed by Niagara Chemical Division of FMC Corporation
    (Shuttleworth et al. 1971) may be used. Acetonitrileisopropanol
    (2:1 v/v) maceration is used for sugar beet roots while sugar beet
    pulp is extracted with 35% v/v water-acetonitrile. After clean-up
    using a Florisil(R) column, residues are determined by gas
    chromatography with microcoulometric detection. The limit of detection
    of the method is 0.05 ppm.

    Endosulfans A and B and endosulfan sulfate may be selectively
    determined by gas chromatography with a flame photometric detector
    operated in the sulfur mode as reported by Bowman et al. (1970).
    Extraction procedures for multicomponent residue analysis of 39
    representative foods utilizing the preceding determinative step have
    also been described by Bowman, et al. (1971).

    Appraisal

    Data from supervised trials on lettuce, cauliflower, and cabbage
    indicate that endosulfan sulfate may comprise 25 to 50% of the total
    weathered residue with endosulfan B usually making up the majority of
    the remainder. There was no evidence to suggest that inclusion of
    endosulfan sulfate in the total residue would require a revision of
    the tolerance of 2 ppm for fruits and vegetables.

    Extensive data from field trials on tea indicate that applications of
    endosulfan in accord with good agricultural practice could result in
    occasional total residues of 35 ppm (range 6.8 - 35 ppm; average 17
    ppm) in the dry manufactured (black) tea picked seven days after
    treatment. In practice this residue level would be highly unlikely
    since only portions of a tea plantation would be treated at one time
    and extensive blending of treated and untreated tea leaves would
    occur. Since tea is brewed with water to make an infusion and the
    extractability of endosulfan residues is normally quite low, residues
    reaching the consumer would rarely exceed 0.08 ppm.

    No measurable residues (<0.1 ppm) were found in sugar beet pulp
    obtained from beets treated aerially at 1 lb a.i./acre.

    Limited data on residues of total endosulfans on rice (peeled and
    unpeeled), rice hulls, and rice straw indicate that residues in peeled
    rice would be below the level of detection (<0.01 ppm) and in
    unpeeled rice would not be greater than 0.06 ppm.

    Application of endosulfan to cotton at 1 lb a.i./acre/application for
    five applications resulted in average total endosulfan residues in the
    ginned cottonseed of 0.20 ppm and in the crude cottonseed oil of 0.15
    ppm. Refined cottonseed oil contained no detectable residues (<0.03
    ppm).

    EXAMPLES OF NATIONAL TOLERANCES
                                                                         
    Country        Tolerance      Crop
                   ppm
                                                                         
    United States  2              apples, apricots, artichokes,
    of America                    beans, beans (dry), broccoli,
                                  brussels sprouts, cabbage,
                                  cauliflower, celery, cherries,
                                  collards, cucumbers, eggplants,
                                  grapes, kale, lettuce,
                                  melons, mustard greens,
                                  nectarines, peaches, pears,
                                  peas, peppers, pineapples,
                                  plums, prunes, pumpkins,
                                  southern peas, spinach, squash,
                                  strawberries, sunflower seed,
                                  tomatoes, turnip greens, watercress

                   1              alfalfa hay, cottonseed

                   0.5            milk fat, sugarcane

                   0.2            meat, fat, and meat byproducts
                                  of cattle, goats, hogs, horses,
                                  and sheep, carrots, sweet corn
                                  (kernels plus cob), filberts,
                                  macadamia nuts, pecans, potatoes,
                                  safflower seed, sweet-potatoes, walnuts
                                                                         


    Total diet samples collected in Germany did not contain measurable
    residues (<0.001 ppm) of endosulfan. In the United States of America,
    total diet samples collected in 1968 and 1969 revealed an increase in
    the incidence of total endosulfan residues in the latter survey
    period. In 1968, endosulfan residues (range, 0.008-0.134 ppm) were
    found in only three out of 360 composites while in 1969, 16 out of 360
    composites contained endosulfan residues ranging from a trace to 0.042
    ppm. Preparation by a dietician of leafy vegetables for consumption
    resulted in retention of 55% of total endosulfan residues.

    Adequate and selective methods of analysis for residues of endosulfan
    A, endosulfan B, and endosulfan sulfate in fruits, vegetables, dry
    tea, rice, cottonseed, and cottonseed oil are available. Special
    extraction procedures for samples of high sugar content have been
    developed.

    RECOMMENDATIONS FOR TOLERANCES, TEMPORARY TOLERANCES OR PRACTICAL
    RESIDUE LIMITS

    Tolerances

              Tea (dry, manufactured)      30 ppm
              Fruits and vegetables        2 ppm
              Cottonseed                   0.5 ppm
              Cottonseed oil (crude)       0.2 ppm
              Rice (unpeeled)              0.1 ppm

    The residues of endosulfan A, endosulfan B, and endosulfan sulfate are
    to be determined individually but expressed as their sum.

    The above tolerances are to apply to raw agricultural products moving
    in commerce unless otherwise indicated. In the case of fruit and
    vegetables the tolerances should be applied as soon as practicable
    after harvest and in any event prior to actual retail to the public.

    FURTHER WORK OR INFORMATION

    Desirable

    1.   Metabolic studies in man, with particular reference to storage of
         the original compound and metabolites (see FAO/WHO, 1969).

    2.   Further data on residue levels in rice.

    3.   Information on the latest use patterns of endosulfan, especially
         on the specific fruits and vegetables to which it is applied in
         various countries.

    REFERENCES

    Bowman, M. C., and Beroza, M. (1970) GLC retention times of pesticides
    and metabolites containing phosphorus and sulfur on four thermally
    stable columns. J. Assoc. Off. Anal. Chem. 53(3), 499-508

    Bowman, M. C., Beroza, M., and Hill, K. R. (1971) Chromatograms of
    foods for multicomponent residue determination of pesticides
    containing phosphorus and/or sulfur by GLC with flame photometric
    detection. J. Assoc. Off. Anal. Chem. 54(2), 346-358

    Corneliussen, P. E. (1969) Pesticide residues in total diet samples
    (IV). Pesticides Monit. J. 2(4), 140-152

    Corneliussen, P. E. (1970) Pesticide residues in total diet samples M.
    Pesticides Monit. J. 4(3), 89-105

    Duggan, R. E., and Lipscomb, G. Q. (1969) Dietary intake of pesticide
    chemicals in the United States (II), Pesticides Monit. J. 2(4),
    153-162

    FAO/WHO. (1968) 1967 Evaluations of some pesticide residues in food.
    (FAO/PL:1967/M/11/1; WHO/FOOD ADD./68.30)

    FAO/WHO. (1969) 1968 Evaluations of some pesticide residues in food.
    (FAO/PL:1968/M/9/1; WHO/FOOD ADD./69.35)

    Hinstridge, P.A. (1969) Thiodan (Residues on cottonseed - process
    study). Project No. 015, Report No. R-1133, Niagara Chemical Division,
    FMC Corporation, Research and Development, Richmond, California 94802

    Hoechst. (1966) Farbwerke Hoechst AG, Analytical method for
    determining Thiodan(R) residues in and on vegetable material,
    Analytical Laboratory, Dr Gorbach, Report No. 65/66 E

    Hoechst. (1968) Farbwerke Hoechst AG, Endosulfan residues in a total
    diet sample collected in the Federal Republic of Germany. Analytical
    Laboratory, Dr Gorbach, Report No. 95/68

    Hoechst. (1969) Farbwerke Hoechst AG, Endosulfan on/in lettuce,
    Analysis report, Analytical Laboratory

    Hoechst. (1971) Hoechst Belgium SA, Endosulfan on/in lettuce, Analysis
    report

    Hoechst. (1971) Hoechst-Holland NV, Endosulfan on/in cauliflower,
    Analysis report

    Hoechst-Holland NV, Endosulfan on/in red cabbage, Analysis report

    Farbwerke Hoechst AG, Endosulfan on/in cabbage, Analysis reports,
    Sample No. 24, 25, 26, 27, 101, 102, 103, 104, 105, 106, Analytical
    Laboratory

    American Hoechst Corp., Food Additive Petition, Thiodan on Tea,
    Experimental and Residue Data, Exhibit C-10: Tocklai, Assam, Northeast
    India; Exhibit C-12: United Planters Assoc., Southern India Tea
    Research Station, Cinchona, Coimbatore

    Farbwerke Hoechst, AG, Residues of Endosulfan and Endosulfan Sulfate
    on Rice and Rice Straw from the Philippines, Analysis Report

    Li, C. F., Bradley, R. L. jr., and Schultz, L. H. (1970) Fate of
    organo-chlorine pesticides during processing of milk into dairy
    products. J. Assoc. Off. Anal. Chem. 53(1), 127-139

    Shuttleworth, J. M. (1971) Determination of endosulfan and endosulfan
    sulfate residues in sugar beet roots and sugar beet pulp. Project No.
    015, Report No. M-2866, Niagara Chemical Division, FMC Corporation
    Research and Development, Richmond, California 94802
    


    See Also:
       Toxicological Abbreviations
       Endosulfan (EHC 40, 1984)
       Endosulfan (HSG 17, 1988)
       Endosulfan (PIM 576)
       Endosulfan (FAO Meeting Report PL/1965/10/1)
       Endosulfan (FAO/PL:1967/M/11/1)
       Endosulfan (FAO/PL:1968/M/9/1)
       Endosulfan (WHO Pesticide Residues Series 4)
       Endosulfan (WHO Pesticide Residues Series 5)
       Endosulfan (Pesticide residues in food: 1982 evaluations)
       Endosulfan (Pesticide residues in food: 1989 evaluations Part II Toxicology)
       Endosulfan (JMPR Evaluations 1998 Part II Toxicological)