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Introduction
Published in Jamie Bartram, Richard Ballance, Water Quality Monitoring, 1996
Jamie Bartram, Richard Ballance
✓ Ammonium acetate buffer solution. Dissolve 250gNH4C2H3O2 in 150ml water. Add 700ml concentrated (glacial) acetic acid. Prepare new reference standards with each buffer preparation because even a good grade of NH4C2H3O2 contains a significant amount of iron.
The effect of urea-formaldehyde adhesive modification with propylamine on the properties of manufactured plywood
Published in The Journal of Adhesion, 2023
Jakub Kawalerczyk, Joanna Walkiewicz, Magdalena Woźniak, Dorota Dziurka, Radosław Mirski
Adhesives were cured in the laboratory oven at 120°C, ground using IKA A10 basic laboratory mill (Staufen, Germany) and sieved to obtain a dimensional fraction of 0.125 mm × 0.125 mm for further analysis. Fourier transform infrared spectroscopy (FTIR) technique was used for characterization of the adhesives. The obtained powder was mixed with KBr at a 1/200 mg ratio. Spectra were registered using Alpha FTIR spectrometer from Bruker Optics GmbH (Ettlingen, Germany) with the Fourier transform range of 400–4000 cm−1 at the resolution of 4 cm−1, registering 16 scans. Content of formaldehyde in the cured adhesive was investigated with the use of perforator method according to EN 120[28] modified by applying the assumptions of Dziurka and Mirski.[29] The analysis was performed on 5 ± 0.01 g of the adhesive powder subjected to the extraction by means of boiling toluene in a perforator apparatus. Content of formaldehyde in the obtained aqueous solution was determined by spectrophotometry using the ammonium acetate and acetylacetone method. The absorbance of samples was measured at 412 nm on a Biosens UV-5600 spectrophotometer (Warsaw, Poland). Extraction was performed three times for each variant and thus, the result is the average of three measurements.
Removal of tartrazine, ponceau 4R and patent blue V hazardous food dyes from aqueous solutions with ZnAl-LDH/PVA nanocomposite
Published in Journal of Dispersion Science and Technology, 2023
Ofeliya O. Balayeva, Abdulsaid A. Azizov, Mustafa B. Muradov, Rasim M. Alosmanov
The buffer solutions were used to study the optimal pH of adsorption of dye compounds onto ZnAl-LDH/PVA nanocomposite using hydrochloric acid (HCl), acetic acid (CH3COOH), ammonium acetate (CH3COONH4) and ammonium hydroxide (NH4OH). Thus, as pH 1 and pH 2 solutions were used 10−1 M and 10−2 M hydrochloric acid solutions, respectively. Buffer solutions of pH 3- pH 7 were prepared using different ratios of 10−1 M CH3COOH and 10-1 M CH3COONH4. Buffer solutions of pH 8- pH 11 were prepared using different ratios of 10−1 M NH4OH and 10−1 M CH3COONH4. The pH of the solutions was measured on a Mattler Toledo pH meter. The volumes of acetic acid, ammonium acetate salt solution and ammonium hydroxide solution used in the preparation of the ammonium acetate buffer solution were calculated using acid-salt and base-salt concentration ratios (2) and (3).[16] where: pKa - acid number of acetic acid; ca - concentration of acetic acid; cs - concentration of ammonium acetate salt; pKb - basic number of ammonium hydroxide; cb is the concentration of ammonium hydroxide.
The Effects of Ozone-Enriched Storage Atmosphere on Pesticide Residues and Physicochemical Properties of Table Grapes
Published in Ozone: Science & Engineering, 2019
Acetonitrile and methanol of more than 99.9% purities were purchased from Scharlau Chemie SA (Barcelona, Spain) and Sigma-Aldrich Chemie GmbH (Deisenhofen, Germany), respectively. Ammonium acetate, magnesium sulfate, acetic acid, and anhydrous sodium acetate were purchased from Sigma Aldrich. Primary–secondary amine was obtained from Agilent Technologies (Palo Alto, CA, USA). A mixture of analytical standards of pesticides (containing 100 μg mL−1 of each compound, in acetone) was obtained from Chem-Lab NV (Zedelgem, Belgium). Commercial products named Quadris (250 g L−1 azoxystrobin, Syngenta Crop Protection AG, Basel, Switzerland), Nimrod (250 g L−1 bupirimate, Syngenta Crop Protection AG, Basel, Switzerland), Angel 50 WP (50% carbendazim, Dogal Kimyevi Mad. A.S. Istanbul, Turkey), Trigger 100 EC (100 g L−1 penconazole, Agrotez Tarim San. A.S., Istanbul, Turkey), Superol EW 50 (50 g L−1 triadimenol, Dogal Kimyevi Mad. A.S. Istanbul, Turkey), and Flint 50 WG (50% trifloxystrobin, Bayer CropScience, Monheim, Germany) were used for pesticide treatments of grapes in the vineyard. The MRLs of azoxystrobin, bupirimate, carbendazim, penconazole, trifloxystrobin, and triadimenol are 0.2, 0.1, 0.1, 0.3, 0.1, and 0.05 mg kg−1 in grapes, respectively, in the related legislation in Turkey. Pesticide amounts were calculated based on their maximum recommended label rates.