Influence of PVA emulsion on leaching of boron and copper from wood and efficacy on wood decay fungi

Borove spojine učinkovito delujejo proti glivam razkrojevalkam, a se na žalost v vlažnem okolju izpirajo iz lesa. Z namenom doseči čim boljšo vezavo v les, smo borovo kislino, boraks in bakrov(II) sulfat pentahidrat kombinirali s polivinil acetatno (PVA) emulzijo. Z izbranimi pripravki smo impregnirali vzorce smreke (Picea abies) in jih izpostavili trem različnim glivam razkrojevalkam lesa (Antrodia vaillantii, Gloeophyllum trabeum in Trametes versicolor) po postopku mini blok. Del impregniranih vzorcev smo izpirali v skladu s standardom SIST EN 1250-2. Ugotovili smo, da dodatek PVA-emulzije rahlo izboljša vezavo borovih in bakrovih ionov v les. Smrekovina, impregnirana s pripravki z najnižjo koncentracijo borovih učinkovin (cB = 0,1 %), je odporna na vse testne glive, medtem ko je les, zaščiten z raztopinami na osnovi bakra, dobro zaščiten pred glivama Gloeophyllum trabeum in Trametes versicolor in neustrezno zaščiten pred glivo Antrodia vaillantii. Dodatek emulzije PVA že sam po sebi nekoliko zavre delovanje gliv in izboljša delovanje bakrovih in borovih učinkovin.Boron compounds are very effective fungicides, but they leach from wood in wet environments, unfortunately. In order to improve boron fixation, boric acid, borax and copper(II) sulphate were combined with polyvinyl acetate emulsion (PVA). Selected preservative solutions were chosen for impregnation of Norway spruce wood specimens (Picea abies). Wood blocks were exposed to three wood decay fungi Antrodia vaillantii, Gloeophyllum trabeum and Trametes versicolor according to the mini block procedure. Part of impregnated specimens was leached according to the EN 1250-2 procedure. The results showed that addition of PVA emulsion slightly improves copper and boron fixation. Spruce wood impregnated with the lowest concentration of boron based solutions (cB = 0.1%) was found resistant against tested fungi. In contrast, wood blocks impregnated with copper were sufficiently protected against G. trabeum and T. versicolor but not against A. vaillantii. Furthermore, PVA itself has a negative impact on fungal growth, and it improves performance of boron and copper based aqueous solutions

Utjecaj polietilenske i oksidirane polietilenske voštane emulzije na dinamiku ispiranja borne kiseline iz impregnirane smrekovine

Boron biocides belong to the most frequently used ingredients of commercial wood preservatives. They are very effective fungicides and insecticides, but they do not react with wood and thus leach from it in wet applications. This fact signifi cantly limits use of boron compounds in the field of wood preservation. In order to reduce leaching of boric acid, the emulsion of polyethylene (WE1) and an emulsion of oxidized polyethylene (WE6) wax were combined with boric acid (cB = 0.1 % or 0.5 % of boron). Spruce wood specimens were vacuum impregnated and afterwards leached according to the prCEN/TS 15119-1, EN 1250-2 and EN 84 procedures. The results showed that the boron leaching is predominantly infl uenced by moisture content of wood during leaching, and furthermore by the concentration gradient (frequency of water replacement). The fact that the prCEN/TS 15119-1 leaching procedure is less severe than other two methods is also refl ected in the results. The results of the EN 84 and ENV 1250 test are comparable, while the results of the prCEN/TS 15119-1 testing are not in line with the other two methods. Considerable portions of boron are leached from wood in the first leaching cycles, already. WE6 wax emulsion (oxidized polyethylene wax emulsion) in combination with heat treatment reduces boron leaching to a certain extent. On the other hand, impregnation of wood with WE1 (polyethylene wax emulsion) does not reduce it and it even enhances it.Biocidi bora pripadaju najčešće upotrebljavanim sastojcima komercijalnih zaštitinih sredstava za drvo. Vrlo su učinkovita zaštita od gljiva i insekata, no ne vežu se s drvom i stoga su skloni ispiranju iz drva, posebno kada se takvo drvo primjenjuje u vlažnim uvjetima. Ta činjenica znatno ograničava upotrebu spojeva bora na području zaštite drva. U nastojanju da se smanji ispiranje borne kiseline, polietilenska emulzija (WE1) i oksidirana polietilenska voštana emulzija (WE6) kombinirane su s bornom kiselinom (cB = 0,1 ili 0,5 % bora). Uzorci smrekovine vakuumski su impregnirani i nakon toga ispirani prema procedurama opisanim u prCEN/TS 15119-1, EN 1250-2 i EN 84. Rezultati su pokazali da na ispiranje bora najviše utječe sadržaj vode u drvu tijekom ispiranja, a zatim gradijent koncentracije (frekvencija zamjene vode). Činjenica da je testiranje ispiranja prema proceduri prCEN/TS 15119-1 manje strogo od druge dvije metode odražava se i na rezultate ispitivanja. Rezultati ispitivanja prema procedurama EN 84 i ENV 1250 usporedivi su, dok se rezultati prema proceduri testiranja prCEN/TS 15119-1 ne mogu usporediti s rezultatima dobivenim drugim dvjema metodama. Znatan dio bora iz impregniranog drva ispire se već u prvom ciklusu ispiranja. WE6 emulzija (oksidirana polietilenska voštana emulzija) u kombinaciji s termičkom obradom donekle smanjuje ispiranje bora. Nasuprot tome, impregnacija drva s WE1 (polietilenskom emulzijom) ne smanjuje već, naprotiv, pojačava ispiranje bora

Utjecaj polietilenske i oksidirane polietilenske voštane emulzije na dinamiku ispiranja borne kiseline iz impregnirane smrekovine

Boron biocides belong to the most frequently used ingredients of commercial wood preservatives. They are very effective fungicides and insecticides, but they do not react with wood and thus leach from it in wet applications. This fact signifi cantly limits use of boron compounds in the field of wood preservation. In order to reduce leaching of boric acid, the emulsion of polyethylene (WE1) and an emulsion of oxidized polyethylene (WE6) wax were combined with boric acid (cB = 0.1 % or 0.5 % of boron). Spruce wood specimens were vacuum impregnated and afterwards leached according to the prCEN/TS 15119-1, EN 1250-2 and EN 84 procedures. The results showed that the boron leaching is predominantly infl uenced by moisture content of wood during leaching, and furthermore by the concentration gradient (frequency of water replacement). The fact that the prCEN/TS 15119-1 leaching procedure is less severe than other two methods is also refl ected in the results. The results of the EN 84 and ENV 1250 test are comparable, while the results of the prCEN/TS 15119-1 testing are not in line with the other two methods. Considerable portions of boron are leached from wood in the first leaching cycles, already. WE6 wax emulsion (oxidized polyethylene wax emulsion) in combination with heat treatment reduces boron leaching to a certain extent. On the other hand, impregnation of wood with WE1 (polyethylene wax emulsion) does not reduce it and it even enhances it.Biocidi bora pripadaju najčešće upotrebljavanim sastojcima komercijalnih zaštitinih sredstava za drvo. Vrlo su učinkovita zaštita od gljiva i insekata, no ne vežu se s drvom i stoga su skloni ispiranju iz drva, posebno kada se takvo drvo primjenjuje u vlažnim uvjetima. Ta činjenica znatno ograničava upotrebu spojeva bora na području zaštite drva. U nastojanju da se smanji ispiranje borne kiseline, polietilenska emulzija (WE1) i oksidirana polietilenska voštana emulzija (WE6) kombinirane su s bornom kiselinom (cB = 0,1 ili 0,5 % bora). Uzorci smrekovine vakuumski su impregnirani i nakon toga ispirani prema procedurama opisanim u prCEN/TS 15119-1, EN 1250-2 i EN 84. Rezultati su pokazali da na ispiranje bora najviše utječe sadržaj vode u drvu tijekom ispiranja, a zatim gradijent koncentracije (frekvencija zamjene vode). Činjenica da je testiranje ispiranja prema proceduri prCEN/TS 15119-1 manje strogo od druge dvije metode odražava se i na rezultate ispitivanja. Rezultati ispitivanja prema procedurama EN 84 i ENV 1250 usporedivi su, dok se rezultati prema proceduri testiranja prCEN/TS 15119-1 ne mogu usporediti s rezultatima dobivenim drugim dvjema metodama. Znatan dio bora iz impregniranog drva ispire se već u prvom ciklusu ispiranja. WE6 emulzija (oksidirana polietilenska voštana emulzija) u kombinaciji s termičkom obradom donekle smanjuje ispiranje bora. Nasuprot tome, impregnacija drva s WE1 (polietilenskom emulzijom) ne smanjuje već, naprotiv, pojačava ispiranje bora

Comparison of standard procedures for estimation of biocides leaching from impregnated wood

Izpiranje aktivnih učinkovin iz impregniranega lesa je eden izmed najpomembnejših kriterijev za presojanje uporabnosti zaščitnih pripravkov za zaščito lesa na prostem. V te namene uporabljamo več različnih standardnih in nestandardnih postopkov: SIST EN 84, SIST EN V 1250-2 in priporočilo OEC D. V sklopu te raziskave smo med seboj primerjali izpiranje bakrovih in borovih spojin iz lesa, zaščitenega s pripravki: (a) vodno raztopino bakrovega sulfata, (b) bakeretanolaminskim komercialnim pripravkom Silvanolin, (c) vodno raztopino borove kisline in (d) kombinacijo borove kisline in vodne emulzije voska montana. Globinsko impregnirane vzorce smo izpirali in določili delež izpranega Cu in B. Največji delež biocidov smo izprali iz lesa zmetodo SIST EN 84, najmanj pa z metodo OEC D. Kakorkoli, z vsemi testiranimi metodami smo prišli do istega vrstnega reda pripravkov glede na delež izpranih aktivnih učinkovin iz lesa.Leaching of active ingredients from impregnated wood is one of the most frequently applied criteria for assessing the suitability of impregnated wood to be used in outdoor applications. For this purposes, several standard and nonstandard procedures are applied. Within the framework of this research, leaching of copper and boron compounds from wood, impregnated with four different wood preservatives, were compared: (a) aqueous solution of copper sulphate, (b) commercial copper-ethanolamine based solution Silvanolin, (c) aqueous solution of boric acid and, (d) combination of boric acid and montanic wax emulsion. Pressure impregnated specimens were afterwards leached according to the three different standards: SIST EN 84, SIST EN 1250 and OECD recommendation. The highest portion of leached biocides were determined according to the SIST EN 84 procedure, the lowest portion according to OECD recommendation. All three methods applied, however give us the same ranking of wood preservatives regarding the amount of emitted active ingredients

Inhibition of ache by malathion and some structuraly similar compounds

Inhibition of bovine serum acetylcholinesterase by in vitro exposure to malathion, malaoxon, isomalathion and diethyl maleate was investigated to elucidate the mechanism of the enzyme interaction with structurally similar organophosphorus compounds. IC50 (half maximum inhibitory concentrations) were determined by Hill analysis of experimentally obtained inhibition curves. The values (2.87 ± 0.24)x10-6 M, (2.65±0.61)x10-6M, (3.01±0.36)x10-4 M and (5.69 ±0.7)x10-2 M were obtained for malaoxon, isomalathion, malathion and their hydrolysis product diethyl maleate, respectively. The relationship between the structure of the compounds and their potency to inhibit the enzyme activity was discussed.Physical chemistry 2006 : 8th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 26-29 September 200

Supercritical Carbon Dioxide Extraction of Four Medicinal Mediterranean Plants: Investigation of Chemical Composition and Antioxidant Activity

With everyday advances in the field of pharmaceuticals, medicinal plants have high priority regarding the introduction of novel synthetic compounds by the usage of environmentally friendly extraction technologies. Herein, a supercritical CO2 extraction method was implemented in the analysis of four plants (chamomile, St. John’s wort, yarrow, and curry plant) after which the non-targeted analysis of the chemical composition, phenolic content, and antioxidant activity was evaluated. The extraction yield was the highest for the chamomile (5%), while moderate yields were obtained for the other three plants. The chemical composition analyzed by gas chromatographyhigh-resolution mass spectrometry (GC-HRMS) and liquid chromatography- high-resolution mass spectrometry (LC-HRMS) demonstrated extraction of diverse compounds including terpenes and terpenoids, fatty acids, flavonoids and coumarins, functionalized phytosterols, and polyphenols. Voltammetry of microfilm immobilized on a glassy carbon electrode using square-wave voltammetry (SWV) was applied in the analysis of extracts. It was found that antioxidant activity obtained by SWV correlates well to 1, 1-diphenyl-2-picrylhidrazine (DPPH) radical assay (R2 = 0.818) and ferric reducing antioxidant power (FRAP) assay (R2 = 0.640), but not to the total phenolic content (R2 = 0.092). Effective results were obtained in terms of activity showing the potential usage of supercritical CO2 extraction to acquire bioactive compounds of interest

Inhibition of AChE by malathion and some structurally similar compounds

Inhibition of bovine erythrocyte acetylcholinesterase (free and immobilized on controlled pore glass) by separate and simultaneous exposure to malathion and malathion transformation products which are generally formed during storage or through natural or photochemical degradation was investigated. Increasing concentrations of malathion, its oxidation product malaoxon, and its isomerisation product isomalathion inhibited free and immobilized AChE in a concentration-dependent manner. K-I, the dissociation constant for the initial reversible enzyme inhibitor-complex, and k(3), the first order rate constant for the conversion of the reversible complex into the irreversibly inhibited enzyme, were determined from the progressive development of inhibition produced by reaction of native AChE with malathion, malaoxon and isomalathion. KI values of 1.3 x 10(-4) M-1, 5.6 x 10(-6) M-1 and 7.2 x 10(-6) M-1 were obtained for malathion, malaoxon and isomalathion, respectively. The IC50 values for free/immobilized AChE, (3.7 +/- 0.2)10(-4) M/(1.6 +/- 0.1)10(-4), (2.4 +/- 0.3)10(-6)/(3.4 +/- 0.1)10(-6) M and (3.2 +/- 0.3)10(-6) M/(2.7 +/- 0.2)10(-6) M, were obtained from the inhibition curves induced by malathion, malaoxon and isomalathion, respectively. However, the products formed due to photoinduced degradation, phosphorodithioic O,O,S-trimethyl ester and O,O-dimethyl thiophosphate, did not noticeably affect enzymatic activity, while diethyl maleate inhibited AChE activity at concentrations GT 10 mM. Inhibition of acetylcholinesterase increased with the time of exposure to malathion and its inhibiting by-products within the interval from 0 to 5 minutes. Through simultaneous exposure of the enzyme to malaoxon and isomalathion, an additive effect was achieved for lower concentrations of the inhibitors (in the presence of malaoxon/isomalathion at concentrations 2 x 10(-7) M/2 x 10(-7) M, 2 x 10(-7) M/3 x 10(-7) M and 2 x 10(-7) M/4.5 x 10(-7)M), while an antagonistic effect was obtained for all higher concentrations of inhibitors. The presence of a non-inhibitory degradation product (phosphorodithioic O,O,S-trimethyl ester) did not affect the inhibition efficiencies of the malathion by-products, malaoxon and isomalathion

Influence of PVA emulsion on leaching of boron and copper from wood and efficacy on wood decay fungi

Boron compounds are very effective fungicides, but they leach from wood in wet environments, unfortunately. In order to improve boron fixation, boric acid, borax and copper(II) sulphate were combined with polyvinyl acetate emulsion (PVA). Selected preservative solutions were chosen for impregnation of Norway spruce wood specimens (Picea abies). Wood blocks were exposed to three wood decay fungi Antrodia vaillantii, Gloeophyllum trabeum and Trametes versicolor according to the mini block procedure. Part of impregnated specimens was leached according to the EN 1250-2 procedure. The results showed that addition of PVA emulsion slightly improves copper and boron fixation. Spruce wood impregnated with the lowest concentration of boron based solutions (cB = 0.1%) was found resistant against tested fungi. In contrast, wood blocks impregnated with copper were sufficiently protected against G. trabeum and T. versicolor but not against A. vaillantii. Furthermore, PVA itself has a negative impact on fungal growth, and it improves performance of boron and copper based aqueous solutions