Dichloromethane

The analytical portions of the leaves (16 disks, 1 cm in diameter each) and flowers (8 pieces), both with the addition of 100 mL of water, and fruits (16 pieces) were homogenized in a Waring Commercial 8010 EG blender (Waring, USA) with 150 mL of acetone (Chempur, Poland) and filtered through a Büchner funnel under vacuum. The blender jar was flushed with 50 mL of acetone, and the washings were used to wash the filter cake. One-fifth of the filtrate (the equivalent of approximately 15.4 g of fruit and approximately 0.1 g of leaves) was used for further analysis. It was placed in a separatory funnel together with 100 mL of 2.5% sodium sulfate (VI) (Chempur, Poland) solution. The pesticide residues were extracted three times with 20, 10, and 10 mL of dichloromethane (Chempur, Poland). The combined extracts were evaporated to dryness, dissolved in 10 mL of petroleum ether and purified using a Florisil (Chempur, Poland) mini-column (Sadło et al. 2014 (link), 2015 (link)). The pesticide residues were eluted with a 70-mL mixture of 3:7 (v/v) ethyl ether:petroleum ether (Chempur, Poland) as well as with a 70-mL mixture of 3:7 (v/v) acetone:petroleum ether. The solvents were evaporated to dryness, and the residue was transferred quantitatively using petroleum ether into a 10-mL volumetric measuring flask.

Silicon wafers were obtained from ON Semiconductor (Roznov, Czech Republic). Hydrogen peroxide (30%, p.a.), sulfuric acid (96%, p.a.), hydrochloric acid (35–38%, p.a.), toluene (p.a.), tetrahydrofuran (THF, p.a.), dichloromethane (DCM, p.a.), ethanol (p.a.), and methanol (p.a.) were purchased from Chempur (Piekary Slaskie, Poland). In addition to this, (3-aminopropyl) trimethoxysilane (APTES, 99%), α-bromophenylacetyl chloride (BPA-Cl, technical, 80%), triethylamine (TEA, puriss. p.a., ≥99.5%, GC), ethyl α-bromophenylacetate (EBPA, 97%), and methyl methacrylate (MMA, 99%, ≤30 ppm MEHQ as an inhibitor) were purchased from Sigma Aldrich. Anisole (>99%), tetrabutylammonium bromide (TBABr, 99%) were purchased from Fluorochem (Hadfield, UK). Iron (III) bromide (FeBr₃, anhydrous, >98%) was obtained from Alfa Aesar and stored in an argon atmosphere. MMA was passed through the basic alumina column to remove inhibitors before the polymerization, while anisole was passed through a neutral alumina column and dried over molecular sieves under argon atmosphere. Rest of chemicals were used as received.

The following materials were used in the study: ε-caprolactone (purity 97%, Sigma Aldrich, Darmstadt, Germany), calcium hydride (purity 95%, Sigma Aldrich), caprolactone (purity 97%, Sigma Aldrich), lamivudine (secondary pharmaceutical standard, purity 100%, Sigma Aldrich), clarithromycin (purity 100%, Sigma Aldrich), acyclovir (purity 100%, Sigma Aldrich), rifampicin (purity 100%, Sigma Aldrich), tin 2-ethylhexanoate (purity 92.5–100% Sigma Aldrich), poly(vinyl alcohol) (31 kDa, degree of hydrolysis 86.7–88.7%, Roth, Zielona Góra, Poland), dichloromethane (purity 98.5%, Chempur, Piekary Śląskie, Poland), methanol (purity 99.5%, Chempur), CDCl₃ (purity 100%, Sigma Aldrich), tetrahydrofuran (purity 99.8%, Chempur), acetonitrile (purity 99.9%, Sigma Aldrich), ammonium acetate (purity 97–100%, Chempur), glacial acetic acid (purity 99.5%, Chempur), polystyrene standards (analytical standard grade, Sigma Aldrich), sodium azide (purity 99.0%, Sigma Aldrich), and phosphate saline buffer (0.01 M phosphate buffer, 0.0027 M potassium chloride and 0.137 M sodium chloride, pH 7.4, purity 99.9%, Sigma Aldrich).

Phenolic acids: SA, CA, and FA, β-sitosterol ≥ 70% (mainly impurities campesterol and β-sitostanol), 2,2-diphenyl-1-picrylhydrazyl radical (DPPH, 95%), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS), acetic anhydride, 4-(dimethylamino)pyridine (DMAP), 6-hydroxy-2,5,7,8-tetramethylchromane-2-carboxylic acid (Trolox), dicyclohexylcarbodiimide (DCC), potassium persulfate and potassium carbonate were obtained from Merck, Warszawa, Poland. Methanol, ethanol, ethyl acetate, dichloromethane, chloroform, hexane, and hydrochloric acid were purchased from Chempur, Piekary Śląskie, Poland. Thin layer chromatography (TLC) plates with fluorescent indicator UV₂₅₄, trade name ALUGRAM R SIL G/UV₂₅₄ (Macherey-Nagel, Dueren, Germany) and silica gel (pore size 60Å, 230–400 mesh, Kieselgel, Macherey-Nagel, Dueren, Germany) were purchased from Alchem, Toruń, Poland.

3,4-Dimethoxythiophene (>97%), p-toluenesulfonic acid monohydrate (p-TSA, 98%), and magnesium sulfate (anhydrous 99.5%) were all purchased from Fluorochem (Derbyshire, UK). Triethylamine (TEA, >99.5%), 3-aminopropyl-trimethoxysilane (APTES, 98%), α-bromoisobutyryl bromide (BIB, 98%), 1,1,4,7,10,10-hexamethyltriethylenetetramine (HMTETA, 97%), copper(II) bromide (99.999%), copper(I) bromide (99.999%), and DMF (>99.9%) were purchased from Sigma-Aldrich (St Louis, MO, USA). Dichloromethane (DCM, p.a.), chloroform (p.a.), toluene (p.a.), dimethylformamide (DMF, p.a.), tetrahydrofuran (THF, p.a.), methanol (p.a.), ethanol (99.9%), hydrogen peroxide (30% p.a.), and ammonia solution (30% p.a.) were all purchased from Chempur (Piekary Slaskie, Poland). Hydrochloric acid (35–38% p.a.) was obtained from POCH S. A. (Gliwice, Poland). 1,1,1-Tris(hydroxymethyl)ethane (>98%) was obtained from TCI Co. (Tokyo, Japan). Iron(III) chloride (99.5%) was purchased from Lab-Scan (Gliwice, Poland). Distilled chloroform and methanol used for sample purification after oxidative polymerization were additionally dried under molecular sieves (0.3 nm, Merck, Darmstadt, Germany) before use. The rest of the chemicals were used as received.

After extraction of surface residues with petroleum ether, four analytical portions of flowers collected on a given day were combined into single samples to increase the residue concentration in final extract. Likewise, leaf samples were processed. They were homogenised in the Waring Commercial 8010 EG blender (Waring, USA) with 100 mL of distilled water and 150 mL of acetone (Chempur, Poland) and filtered on the Büchner’s funnel under vacuum. The blender jar was flushed with 50 mL of acetone, and the washings were used to rinse the filter cake. One-fifth of the obtained filtrate volume was used for further analyses. The filtrate was transferred to a separatory funnel together with 100 mL of 2.5% sodium sulphate (VI) (Chempur, Poland) solution. Pesticide residues were extracted three times with 20, 10, and 10 mL of dichloromethane (Chempur, Poland). The combined extracts were evaporated to dryness, dissolved in approximately 10 mL of petroleum ether, and purified on a Florisil (Chempur, Poland) mini-column (Sadło et al. 2014 (link); Sadło et al. 2015 ). Pesticides were eluted with 70 mL of a 3:7 (v/v) ethyl ether-petroleum ether (Chempur, Poland) mixture, and then with 70 mL of a 3:7 (v/v) acetone-petroleum ether mixture. The solvents were evaporated to dryness, and the residues were transferred quantitatively with petroleum ether to a 10-mL measuring flask.