Toxicological aspects of cannabinoid, pesticide and metal levels detected in light Cannabis inflorescences grown in Italy.

Recently, the cultivation of light Cannabis, with a total THC content less than 0.6%, has been encouraged due to its industrial and therapeutic potential. This has increased the consumption of hemp for both smoking purposes and food preparation. Even so, Cannabis inflorescences are not subject to EU regulations and standards provided for food and tobacco products. A study was carried out on thirty-one inflorescences samples, collected in different Italian regions, in order to determine cannabinoids, pesticides and metals and to evaluate the exposure of consumers to contaminants and ensure a safe consumption. Contents of THC were always below 0.5%, while CBD ranged between 0.3 and 8.64%. The determination of 154 pesticides showed that 87% of the samples contained fungicides and insecticides in the range 0.01-185 µg/g. The most found are spinosad and cyprodinil. The concentration of metals ranged from 1 to more than 100 µg/g and As, Cd, Co, Cr, Hg, Cu, Mo, Ni and V exceeded the regulatory US limits for inhaled Cannabis products, while Pb exceeded them for both oral and inhaled products. These contaminants are intrinsically toxic and may affect public health. Actions are needed to establish regulatory measures and reduce the adverse effects caused by contaminants in Cannabis.

Determination of pyrethroid pesticide residues in fatty materials by solid-matrix dispersion partition, followed by mini-column size-exclusion chromatography.

The method studied uses a combination of a solid-matrix dispersion partition (SMDP) followed by high-performance size-exclusion chromatography on a minicolumn (HPmSEC) of 7.8 mm I.D. for the separation of pyrethroid (PYR) residues from fatty material. The solid-matrix dispersion extraction is carried out by absorbing a fat solution onto an Extrelut-3 cartridge (filled with a macroporous diatomaceous material) and extracting the PYR residues with acetonitrile. Up to 1 g of fatty material can be extracted with 15 ml acetonitrile. The small amount (mean +/- S.D. = 12.4 +/- 5.9 mg) of fatty material which is eluted into the acetonitrile is further removed by HPmSEC. PYR pesticide residues are collected in a 2-ml fraction between 7 and 9 ml, the column being washed up to 24 ml. The two techniques used in series allow a better removal of fat, a greater input of sample and a lower consumption of solvent compared to the sole SEC on macrocolumns, and a lower limit of determination compared to the sole SEC on minicolumns. Recoveries of 9 PYR out of the 14 investigated residues from soya oil were in the range 66-83% at spiking levels ranging 0.49-2.57 mg/kg, while for 6 PYR residues tested at spiking levels in the range 0.13-0.53 mg/kg the recoveries were in the range 80-111%. Recovery of fluvalinate and permethrin could not be calculated due to interferences from soya oil, while lambda-cyhalothrin, esfenvalerate and tralomethrin gave low recovery. The final extract contains small amount (mean +/- S.D. = 2.4 +/- 0.9 mg) of lipid residue and is not completely free from interferences.

Selective clean-up applicable to aqueous acetone extracts for the determination of carbendazim and thiabendazole in fruits and vegetables by high-performance liquid chromatography with UV detection.

Fungicide residues in vegetables (benomyl, carbendazim, thiabendazole) are analyzed through a clean-up procedure that uses a portion of the aqueous acetone extract prepared for multiresidue methodology. A portion of the aqueous acetone extract (equivalent to 5 g of vegetables) is loaded onto an Extrelut-20 cartridge (the cartridge is filled with a coarse, large-pore diatomaceous material). Then, acetone is partially removed by an upward stream of nitrogen at 2l/min for 30 min. Benzimidazolic fungicides are recovered by percolating the cartridge with 100 ml of 0.1 M phosphoric acid solution, which also serves to convert benomyl to carbendazim. The percolating acid solution is drained on-line through a strong cation-exchange (SCX) solid-phase extraction cartridge with the aid of a slight vacuum. Benzimidazolic fungicides are retained on the SCX cartridge. The phosphoric acid solution is discarded together with the washings of the SCX cartridge, i.e., water followed by methanol-water (75:25), that remove unwanted coextractives. Finally, benzimidazolic fungicides are recovered by eluting the SCX cartridge with methanol-ammonium formate buffer (75:25). The final extract is then analyzed by reversed-phase HPLC with UV detection. Recoveries from crops such as apples, lettuce, strawberries and citrus fruits are generally greater than 80% and no interferences were observed. The clean-up is simple and straightforward, requires only disposable items, water solutions and a few milliliters of solvent and a minimum number of manipulations, and does not require concentration steps or electrical equipment.

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.

Application of solid-phase partition cartridges in the determination of fungicide residues in vegetable samples.

Disposable, ready-to-use cartridges filled with a macroporous diatomaceous material are used to extract in a single step fungicide residues with dichloromethane from aqueous acetone extracts of vegetables. This procedure takes the place of some functions (such as separating funnel partition, drying over anhydrous sodium sulphate and clean-up) usually performed by separate steps in classical schemes. Fourteen fungicides (dichloran, vinclozolin, chlorthalonil, triadimefon, dichlofluanide, procymidone, hexaconazole, captan, folpet, ditalimfos, iprodione, captafol, pyrazophos and fenarimol) were determined using the described procedure with recoveries between 83 and 107% at spiking levels ranging for the different compounds from 0.04 to 0.40 mg/kg. Crops subjected to the described procedure included lettuce, strawberry, apple, yellow pepper and peach, and gave extracts containing a mass of co-extractives 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 preparation and maintenance of equipment. Troublesome emulsions such as those frequently observed in separating funnel partitioning do not occur.

Screening for coumatetralyl in soft drinks by solid-matrix extraction and high-performance liquid chromatography with diode-array detection.

A method was developed for the rapid determination coumatetralyl in cola- and orange-type soft drinks, which includes extraction using solid-matrix column, clean-up by silica cartridge chromatography and reversed-phase high-performance liquid chromatography with diode-array detection. The recovery of coumatetralyl from 50 ml of soft drinks was better than 80% at spiking levels down to 50 micrograms/kg (ppb).

Discrepancies between serum and erythrocyte concentrations of vitamin E in hemodialysis patients: role of HDL-bound fraction of vitamin E.

Recently, we have demonstrated that hemodialysis (HD) patients have higher serum and lower erythrocyte concentrations of vitamin E than controls. It is known that transfer of vitamin E from serum to erythrocyte is mostly due to high-density lipoproteins (HDL). For a better definition of the pattern of distribution of vitamin E in HD patients, we have dosed the amount of vitamin bound to serum HDL fraction. In 8 patients and in 8 healthy controls, we have determined the concentration of serum erythrocyte and HDL-bound vitamin E. The latest was obtained on an ultracentrifuged HDL fraction. HDL fractions from HD patients have been found to contain larger amounts of vitamin E than controls. The previously described higher serum and lower erythrocyte concentrations of vitamin E in HD patients have been confirmed in the study. The deficit of vitamin E in the membranes of erythrocytes from HD patients has been shown to be the result of increased consumption of the vitamin in the erythrocyte membranes, where it represents the major antioxidant agent. However, the finding of increased amounts of vitamin bound to HDL in HD patients suggests that the transfer of the vitamin to the erythrocyte membranes may also be defective.