Clean-up of aqueous acetone vegetable extracts by solid-matrix partition for pyrethroid residue determination by gas chromatography-electron-capture detection.

Disposable, ready-to-use cartridges filled with macroporous diatomaceous material are used to carry out a partition clean-up that, in a single step, is capable of transferring pesticide residues from aqueous acetone extracts into light petroleum-dichloromethane (75:25, v/v). This procedure takes the place of some functions (such as separatory-funnel partition, drying over anhydrous sodium sulphate and partial adsorption clean-up) usually performed by separate steps in classical schemes. Fourteen pyrethroid pesticides, including tefluthrin, tetramethrin, cyphenothrin, cyfluthrin, flucythrinate, tau-fluvalinate, deltamethrin, bioallethrin, fenpropathrin, lambda-cyhalothrin, permethrin, alpha-cypermethrin, esfenvalerate and tralomethrin were determined using the described procedure with satisfactory recoveries for most of them, at spiking levels ranging from 0.08 to 0.82 mg/kg for the different compounds. Crops subjected to the described procedure included strawberry, apple, and orange gave extracts containing a mass of co-extractives that was between 5 and 30 mg. Compared with classical schemes, the described procedure is simple, less labour intensive, allows parallel handling of several extracts and does not require the preparation and maintenance of equipment. Troublesome emulsions such as those frequently observed in separation funnel partitioning do not occur.

Selective, solid-matrix dispersion extraction of organophosphate pesticide residues from milk.

A rapid procedure has been developed that allows a single-step, selective extraction and cleanup of organophosphate (OP) pesticide residues from milk dispersed on solid-matrix diatomaceous material filled into disposable cartridges by means of light petroleum saturated with acetonitrile and ethanol. Recovery experiments were carried out on homogenized commercial milk (3.6% fat content) spiked with ethanolic solutions of 24 OP pesticides, viz., ethoprophos, diazinon, dimethoate, chlorpyrifos-methyl, parathion-methyl, chlorpyrifos-ethyl, malathion, isofenphos, quinalphos, ethion, pyrazophos, azinphosethyl, heptenophos, omethoate, fonofos, pirimiphos-methyl, fenitrothion, parathion, chlorfenvinphos, phenthoate, methidathion, triazophos, phosalone, azinphos-methyl, at levels ranging for the different OP pesticides from 0.02 mg/kg to 1.11 mg/kg. Average recoveries of four replicates were in the range 72-109% for the different OP pesticides, with relative standard deviations (R.S.D.) from ca. 1 to 19%, while dimethoate and omethoate were not recovered. Coextracted fatty material amounted to an average of about 4.0 mg/ml of milk. The extraction procedure requires about 30 min. The main advantages are that extraction and cleanup are carried out in a single step, emulsions do not occur, several samples can be run in parallel by a single operator, reusable glassware is not needed and simple operations are required.

Pesticide residue control in the years 1988-1989 in Italy.

The paper reports the monitoring for pesticide residue contamination of foodstuffs carried out in the years 1988-1989 by the Italian peripheral laboratories officially commissioned for the task. The tables show the analytical data for each class of substrate versus the limits in force at the time. 2506 food samples and 555 samples from the environment were analysed and a total of 16,259 determinations made. The residues were absent in 90% of the cases; the percentage of irregularities was 1.52%. These results confirm the data obtained in previous years, which is particularly significant considering the much larger number of analytical determinations performed this time. It has been deemed convenient to survey specific types of foodstuffs (for example, cereals and animal products) by examining a larger number of samples.

Pesticide residue control in the years 1986-1987.

Results of analytical surveys on pesticide residue levels in foods for the years 1986-1987 are presented. Analytical data obtained from regional laboratories are tabulated in terms of various commodity groups (vegetables, fruit, cereals, processed or derived foodstuffs, other commodities, legumes, environmental samples, others) and are compared with maximum legal tolerances established by the ministerial ordinance (Italian Ministry of Health) 6.6. 1985. On a total number of 4715 determinations of classes of compounds or of single compounds made on 1601 commodities samples, only N 53 (1.1%) violative results appeared. No residue was found at levels exceeding regulatory limits or found in commodities where a tolerance had not been established for a specific pesticide/commodity combination.

Pesticide residue control in the years 1980-1982.

Data on pesticide residue on vegetables, fruits, cereals, and other foods of vegetable or animal origin determined by Provincial Laboratories during the years 1980-1982 are presented and compared with levels permitted by Italian legislation. An analysis of the results obtained from about 3000 samples shows that a high percentage of samples did not contain detectable pesticide residues or had residue levels below the maximum allowed by Italian law: 98% of the vegetables, 94.6% of the fruit, and 97.5% of the cereals (fumigants not considered here). On fruit, some residues exceeding the permissible levels for postharvest compounds, i.e., ethoxyquin, ethylenebisdithiocarbamate (EBDC), and benzimidazolmethylcarbamate (BMC), were found in apples and pears. Residue levels of some organochlorinated compounds slightly exceeding the legal limit were observed in some food samples of animal origin (mainly cow's milk). Comparing the present results with those of previous studies indicates that there has been a general decline in the residue levels of aldrin/dieldrin in milk and milk products.

Pesticide residue control in the years 1983-1985.

Levels of organochlorinated, organophosphate, dithiocarbamic, benzimidazolic, and phthalimidic compounds, as well as some other pesticide residues obtained from Regional Laboratories in the years 1983-1985, were assembled and presented as a part of a study aimed at evaluating food contamination. Approximately 2000 samples of vegetables, fruits, cereals, and food of animal origin were analyzed by local laboratories during the years 1983, 1984, and 1985. Samples were randomly obtained from the market, at production levels, or sometimes at custom sites. Approximately 10,000 determinations of single compounds or classes of compounds were carried out. The analytical results are presented and compared with the Italian maximum residue limits. In the majority of the samples analyzed, either there were no residues or the residues were below the permitted level for the specific pesticide in each commodity. High levels of residues were present in a few cases, mainly with respect to some fungicides in fruits and vegetables and chlorinated compounds in some animal products.

Extensive atrazine pollution of drinking water in the Lombardia region and related public health aspects.

Introduced in 1957, atrazine is a herbicide used worldwide, mainly in corn cultivation areas for weed control. It is only slightly volatile, is highly soluble in water, and is moderately persistent in topsoil, where it is strongly absorbed to organic carbon. Because of these properties, atrazine can leach to ground water and persist for a long time. This work presents the results obtained so far from an investigation initiated because of an emergency situation in the Lombardia Region of Italy caused by the occurrence of levels of atrazine in drinking water exceeding those established by the European Economic Community and Italian regulations. Water samples from almost 3000 wells were analyzed in different laboratories of the Lombardia Region. Atrazine contamination occurred in a significant number of the wells examined. Examination of the analytical data overall leads to the conclusion that the agricultural use of atrazine in the Lombardia Region is a serious source of ground water contamination. In some areas other factors may be responsible for the contamination of ground water (for instance, industrial activities and/or uncontrolled waste discharges). Geological and hydrological characteristics may play an important role in ground water contamination. Purification systems containing active charcoal seem to be highly efficient in removing atrazine from contaminated water.

[Determination of total bromine content in imported cereals and in other foodstuffs (author's transl)]. / Determinazione di bromo totale in cereali importati ed in altri prodotti pronti per il consumo.

Samples of raw cereals imported in Italy and of other foodstuffs that can be treated with bromine-containing fumigants were analysed for the total bromide content. The analysis were carried out by X-ray fluorescence-spectrometry. Results obtained in 145 samples of raw cereals and in 50 samples of other foodstuffs are reported along with some considerations.

Heavy metals and organochlorine residues in marine animals and coastal sediments of the Tirrenean sea around Naples.

A survey of selected heavy metals (Cd, Pb, Hg) and organo-chlorine hydrocarbons (DDT and PCB compounds) concentrations in marine animals and of mercury, DDT and PCB in coastal sediments, began in 1973. The sampling was confined to the Bay of Naples, and to the coast along Santa Maria di Castellabate, a small village about 100 km south of Naples which has recently declared a marine park. The results of this investigation indicate that contamination by the above pollutants is low; the extent of contamination in the bay of Naples, compared to that of the marine park, shows that the level of heavy metals and organochlorine hydrocarbons in the benthic organisms is nearly the same within the two areas, whereas that of the sediments of the bay is significantly higher than in the park.

Evaluation of p,p'-DDE, p,p'-DDT and polychlorobiphenyls (PCBs) levels in samples of human milk from Rome, Florence and the surrounding areas.

Sixty-five samples of human milk obtained from individual donors living in Rome and surrounding areas between 1982 and 1984, and 28 samples from Florence and surrounding areas obtained during 1985 were analyzed for residues of p,p'-DDE, p,p'-DDT and PCBs. Levels of p,p'-DDE were between 5 and 126 ppb (micrograms/kg of milk), with an average value of 45 ppb (median 34). Levels of p,p'-DDT ranged from 1 to 79 ppb, with an average value of 10 ppb (median 7). PCBs were found at levels ranging from 7 to 304 ppb, with an average value of 74 ppb (median 66). As to the p,p'-DDT, when compared to the data previously obtained in Italy during 1975-77, the present findings show a decrease of the average value and a lower incidence of samples with higher values. These effects are less pronounced for the p,p'-DDE. No relevant variation was observed in the levels of PCBs in comparison with the data obtained in Italy during 1981-82.

[Estimate of the dose of chlorinated pesticides consumed daily by the Italian population (1978-1984)]. / Una stima della dose di pesticidi clorurati assunta quotidianamente dalla popolazione italiana (1978-84).

This work reports an estimate of the doses of chlorinated pesticides taken with a total diet by the Italian population in the period 1978-84. Previous researches, carried out in 1971-72, had regarded both uncooked and cooked diets, ready for the consumption. It was found that the amount of the considered pesticides taken in total (HCB, gamma-BHC and total-BHC, Aldrin/Dieldrin, Heptachlor/Heptachlor-epoxide and DDT total-equivalent) calculated as a sum of the percentage of each acceptable daily intake (A.D.I.), at that time recommended was near the limit of acceptability (98.5% for cooked diets and 107.0% for uncooked diets). In addition it was found that nearly the 40% of the dose assumed in all came from milk and its derivates (butter, cheese). Then considering the contribution of milk and derivates to the amount of pollutants assumed with a total diet, a new evaluation has been done, with regard to the period 1978-84, i.e. after the prohibition of the use of these pesticides in Italy and in other industrialized countries. Then the data have been processed, with regard to 211 samples of foods (90 of milk, 45 of cheese, 76 butter) coming from determinations carried out by the Multizonal Laboratory of Hygiene and Prevention of Ferrara, Milano, Udine, Bolzano, Trento, Pescara and from the Institute of Hygiene of Rome University "La Sapienza" in the period mentioned. Furthermore, alimentary consumptions of milk, butter and cheese in 1978-84 have been evaluated, and amounts of chlorinated pesticides taken with these foods have been calculated. Finally the dose taken with these foods has been extrapolated to a total diet. It has come out that the doses (estimated) taken with the total diet have notably decreased between 1971-72 and 1978-84. An anomaly is yet represented by HCB: while the quantity taken with food has decreased from 1971-72 to 1978-84 (from 3.7 to 1.3 micrograms/man/day), the concentrations in human adipose tissues have increased (from 1.02 to 1.99 mg/Kg). It can reasonably mean that assumption of HCB is not prevalently alimentary, but that it is due to other factors of environmental contamination. The data of the doses of chlorinated pesticides taken have also been compared with the respective ADI indicated in 1971-72 and in 1978-84.

Clean-up procedure for the extraction of soil samples in the determination of 2,3,7,8-tetrachlorodibenzo-p-dioxin.

This paper describes the method which was developed in relation to analytical work connected with microbial and physico-chemical degradation experiments on 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Soil samples are best extracted with methanol plus methylene chloride. Microbial preparations are extracted with light petroleum after boiling with methanolic potassium hydroxide. The clean-up consists of a sulphuric acid treatment and chromatography on a multilayer column (Celite + H2SO4/silica gel) followed by alumina column chromatography. The clean-up procedure proved to be suitable for soil samples and microbial preparations even when large quantities of organic matter (hydrocarbons, oils, surfactants) were present.

Survey of DDT-like compounds in Dicofol formulations.

The levels of o,p'-DDE, p,p'-DDE, o,p'-DDT, p,p'-TDE (DDD), and p,p'-DDT were determined in 19 samples of Dicofol formulations commercially available in Italy. The total of DDT-like compounds, calculated on a Dicofol content basis, was in the range 0.63-23.19%, with an average of 8.28%. Setting a requirement of minimum purity for Dicofol technical products is proposed.

Exposure to agricultural treatment residues: some simple statistical considerations based on monitoring data for ethoxyquin on apples.

The data examined here concern ethoxyquin levels, mainly measured in apple samples from the retail market. In this study about three hundred measurements, carried out on apples in Northern-Central Italy and recently published, are examined, with the purpose of defining the main characteristics of value statistical distribution and variability and to optimize sampling criteria. The analysis did not indicate the presence of significantly high levels or consequently significantly high risks; nevertheless, it pointed out some important aspects in data collection and evaluation. First, it appeared that the statistical distribution of data is typically nonsymmetrical, non-Gaussian, and characterized by a tail extending toward the high values. The logarithmic transformation of data appeared useful in order to obtain a Gaussian distribution. As a rule, the data variability appeared to be high. The frequency and distribution of values above the analytical threshold resulted in significant change, both in time and in space. The percentage of positive values (above the analytical threshold) appeared to vary up to a factor of 2-3, as analogously did their geometric mean.(ABSTRACT TRUNCATED AT 250 WORDS)

Survey of ethylenethiourea (ETU) in ethylenebis(dithiocarbamate) (EBDC) fungicides.

Ethylenethiourea (ETU) has been recognized as a compound with adverse toxicological properties. It may occur in ethylenebis(dithiocarbamate) (EBDC) fungicides as a by-product and/or a degradation product. Restrictions have been issued by the Italian Health Authority to keep the level of ETU in EBDC formulations under 0.5% (on an EBDC technical product basis). A survey was carried out on 85 samples of commercial formulations from the Italian market to verify compliance with the above limitation. ETU was extracted by methanol and determined by gas chromatography with a flame ionization detector. Three of the 85 samples (3.5%) exceeded the limit of 0.5% established by the Italian legislation for ETU.