aqueous formaldehyde solution
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Author(s):  
Mitham Al-faliti ◽  
Ashraf Aly Hassan ◽  
Bruce Dvorak

A laboratory-scale bio-trickling filter (BTF) was initialized to evaluate the removal of formaldehyde biologically. However, generating formaldehyde gas in the lab is one of the grand challenges hindering research efforts. Formaldehyde was introduced into the gaseous phase by aerating the required air flowrate through a diluted formaldehyde solution mixed with methanol as a stabilizer by a bubbler. However, achieving stable gaseous influent concentrations of formaldehyde was challenging since it polymerizes while volatilizing. Resulting in paraformaldehyde. The resulting white powder clogged the pipes and generated uneven gaseous concentrations. To solve this problem, sodium hydroxide (NaOH) was added with a phosphate buffer to the aqueous formaldehyde solution to maintain the pH between 7.00-7.20. Additionally, the aqueous solution needed to be heated at 60℃ to eliminate the polymerization. The exhausted formaldehyde by volatilization was replaced by a continuous supply of aqueous diluted formaldehyde solution to keep the volume and mass of the aqueous solution and formaldehyde constant, respectively. Stable gaseous concentration was achieved for extended periods of time and verified by Fourier transform infrared (FTIR) spectroscopy.


2020 ◽  
Vol 18 (1) ◽  
pp. 22
Author(s):  
Edia Rahayuningsih ◽  
Wiratni Budhijanto ◽  
Rizal I. Rosyid ◽  
Yosephine I. Ayuningtyas

Abstrak. Tujuan penelitian ini adalah untuk menentukan jenis dan jumlah bahan pengawet yang secara efektif dapat menghambat reaksi biodegradasi zat warna alami dalam ekstrak gambir (Uncaria gambir) dalam pelarut air, serta menentukan nilai parameter reaksi biodegradasi zat warna alami dalam ekstrak gambir. Ekstrak zat warna alami dari gambir, yang telah bebas padatan, sebanyak 300 mL ditambah asam sitrat (0,006 gram/mL ekstrak) sebagai bahan bahan pengawet. Ekstrak kemudian disimpan dalam reaktor yang ditutup rapat dan dilindungi dari sinar ultra violet. Setiap selang waktu 2 hari, kadar pewarna alami dianalisis dengan metode gravimetri. Percobaan dilakukan dengan cara yang sama untuk 5 jenis pengawet lainnya dan dengan berbagai konsentrasi, yaitu: larutan formalin dalam air, larutan kitosan dalam asam asetat, ekstrak temu kunci (Boesenbergia rotunda L.), ekstrak daun salam (Syzygium polyanthum), dan ekstrak daun bandotan (Ageratum conyzoides L.), masing-masing sebanyak 5 mL larutan atau ekstrak bahan pengawet dalam 40 mL sampel ekstrak. Berdasarkan penelitian ini dapat ditetapkan bahwa larutan formalin dalam air dan larutan kitosan dalam larutan asam asetat 2% merupakan pengawet yang paling efektif menghambat reaksi biodegradasi zat warna alami dalam ekstrak, dibandingkan pengawet lainnya, yaitu: asam sitrat, ekstrak daun salam, ekstrak temu kunci, dan ekstrak daun bandotan. Jumlah formalin dan kitosan yang ditambahkan dalam ekstrak paling efektif berturut-turut adalah 0,017% dan 0,25% v/v. Nilai parameter reaksi biodegradasi zat warna alami dalam ekstrak diperoleh dalam bentuk konstanta kecepatan pertumbuhan spesifik (µ0, hari-1), konstanta saturasi (Ks, g/mL), konstanta kematian (kd, hari -1), rasio kd/µ0, dan yield (Yi). Kata kunci: biodegradasi, gambir, pengawet, pewarna alami. Abstract. Preservation of Natural Dye Extract from Gambir (Uncaria gambir) in Water as Solvent. The purpose of this study was to determine the type and the amount of preservative agent which effectively prevent biodegradation reaction of natural colorant in the aqueous extract of “gambir” (Uncaria Gambir). This study also determined the parameter values in the biodegradation reaction of gambir extract. The experiment was carried out by first preparing 300 mL of filtered gambir extract, into which citric acid as much as 0.006 g/mL was added as a preservative. The extract was then stored in a closed reactor with UV protector. Every two days, sample was drawn from the reactor for gravimetric analysis to determine the colorant concentration. Besides citric acid, the same experiments were also conducted for five other preservatives, which were the aqueous formaldehyde solution, the chitosan dissolved in 2% acetic acid solution, the  extract of “temu kunci” (Boesenbergia rotunda L.), the extract of  Indian bay leaf (Syzygium polyanthum), and the extract of “bandotan leaf” (Ageratum conyzoides L.). This study showed that aqueous formaldehyde solution and chitosan dissolved in 2% acetic acid solution was the most effective preservative to prevent biodegradation reaction of natural colorant in gambir extract, in comparizon to citric acid, “temu kunci”, Indian bay leaf, and “bandotan” leaf. The effective concentrations of formalin and chitosan were 0.017% and 0.25% v/v respectively. The parameters of the biodegradation reaction of the natural colorant in gambir extract in the form of specific growth rate coefficient (µ0, day-1), saturation constant (Ks, g/mL), death constant (kd, day -1), ratio of kd/µ0, and yield (Yi). Keywords: biodegradation, gambir, natural dye, preservative. Graphical Abstract


2020 ◽  
Vol 21 ◽  
Author(s):  
Thiago Scremin Boscolo Pereira ◽  
Ana Letícia Daher Aprígio da Silva ◽  
Tatiana Morosini de Andrade Cruvinel ◽  
Paula Medeiros Passarelli ◽  
Mayara Elisa Rotta Loureiro ◽  
...  

Abstract The morphological knowledge of the salivary glands in wild species is fundamental, since these studiescan be used as conservation strategies, clinical treatments and the preservation of species threatened with extinction. Thus, the aim of the study was to anatomically describe the larger salivary glands: parotid, mandibular, sublingual and molar of the jaguar. For this, two specimens of puma (Puma concolor) were used, after death by road traffic accident, donated by the Clinical Surgical Service Department of the Veterinary Hospital “Dr. Halim Atique “(UNIRP). The animals were fixed with 10% aqueous formaldehyde solution, dissected, descriptively analyzed and photographed. Morphologically, the parotid gland is grayish-yellow in color, distinctly lobulated, and has a semilunar shape. This gland is located in the posterolateral region of the face and at its ventral end we observe the parotid duct. The mandibular gland presents a slightly rounded outline, a grayish color and its surface is covered by a capsule of connective tissue. This gland is located in the posterolateral region of the face and we find the mandibular duct at its ventral end. The monostomatic sublingual gland is located on the rostral border of the mandibular gland and it is covered by the mandibular lymph nodes. The molar gland is a yellowish-gray membranous protuberance, elongated, with rectangular shape and it lies dorsally to the labial commissure. Based on the dissections, we conclude that the morphological and topographic characteristics of salivary glands of puma follow the same structural pattern described for other species of carnivorous mammals (domestic and wild).


2017 ◽  
Vol 45 (1) ◽  
pp. 7 ◽  
Author(s):  
Herson Da Silva Costa ◽  
Radan Elvis Matias de Oliveira ◽  
Ferdinando Vinicius Fernandes Bezerra ◽  
Gleidson Benevides de Oliveira ◽  
Moacir Franco de Oliveira

Background: Galea (Galea spixii) are rodents which are especially distributed in the northeastern region of Brazil, and have economic importance as their meat is used as a source of protein by the regional population.  Currently, they have received attention from researchers in studies involving their morphology. Thus, seeking to contribute information that supports their sanitary management in addition to the lack of literature on their nervous system, our objective was to describe the arterial vascularization of the base of the brain in this species, in order to identify the arterial pattern and arterial circuit behavior, as well as possible variations in these vessels.Materials, Methods & Results: Brains were obtained from 20 animals (10 males and 10 females) aged between 11 and 12 months, obtained from the Wild Animal Multiplication Center (CEMAS) of the Federal Rural Semi-Arid University (UFERSA), under the approval of CEUA/UFERSA (case number 23.091.000653/2014-26 and opinion number 15/2014), euthanized according to anesthetic protocol recommended for rodents (resolution number 714/2002 of the CFMV/ UFERSA) and preserved frozen in a freezer for an average period of 30 days. The animals were thawed and a longitudinal incision was performed in the thoracic region to allow exposure of the aortic arch. Next, they were cannulated in the cranial direction and injected with Noprene Latex “650” stained with water-based white or red pigment. The animals were subsequently fixed in 3.7% aqueous formaldehyde solution for 48 h, and soon after the brain skull cap was dissected and removed, which was then analyzed, photographed and sketched. Of the 20 animals evaluated, 100% presented vertebrobasilar system responsible for encephalic irrigation of the rostral and caudal regions, and anastomosis of the left internal carotid artery was found in only one case (female) (5%), irrigating the rostral region of the encephalon together with the vertebro-basilar system. In the most frequently found arrangement, the unpaired main arteries present at the base of the brain included: ventral spinal, basilar, medial branch of the rostrais cerebral arteries, medial rostral inter-hemisphere; and the pairs: vertebral, cerebellar caudal, middle cerebellar, trigeminal, rostral cerebellar, rostral tectal, caudal cerebral, pituitary, internal ophthalmic, middle cerebral, rostral cerebral, lateral olfactory bulb and internal ethmoid. Arterial circuit formation was observed as being geometrically similar to a complete, closed and elongated hexagon in the caudal-rostral direction, bypassing the mammillary body, the cinereous tuft and the optic chiasm.Discussion: The study of the nervous system, especially on identification of the arteries responsible for supplying the brain is relevant, especially when it comes to a wild species such as in galea considering that little is known about their morphology, and also because it can be used as a model in clinical and surgical studies related to the nervous system. Based on the analyzed animals, we conclude that the arterial vascularization of the base of the brain in galea is type III, similar to the findings in other species of rodents such as in otters and porcupines; and differing from those described for agoutis and mice-moles. The arterial circuit of galea is complete and closed like those described for the agouti and the European beaver, yet differing from that observed for otters and chinchillas which have an open circuit.


1999 ◽  
Vol 28 (10) ◽  
pp. 1131-1132 ◽  
Author(s):  
Junzo Masamoto ◽  
Hajime Nagahara ◽  
Tsuneshi Yokoyama ◽  
Rikio Fujikawa ◽  
Tadashi Tanaka ◽  
...  

1998 ◽  
Vol 53 (9) ◽  
pp. 946-954 ◽  
Author(s):  
Stefan Schmidt ◽  
Laurent Omnès ◽  
Frank W. Heinemann ◽  
Jörg Kuhnigk ◽  
Carl Krüger ◽  
...  

The Mg2+ assisted synthesis of a pyridine-derived tetraalcohol ligand with an NO4 donor set is described. 2,6-Diethylpyridine reacts cleanly with aqueous formaldehyde solution in the presence of 1 equivalent of MgSO4 hydrate in a pressurised vessel to give the quadruply hydroxymethylated product 2,6 -C5H3N[CMe(CH2OH)2]2 (1) as a crystalline solid. Two alkali/alkaline earth metal perchlorate adducts of 1 have been structurally characterised, viz. [(1)2 • LiClC4] (6) and [(1)2 • Ba(ClO4)2 ] (7). The ligand adopts a bridging coordination mode in both 6 (distorted tetrahedral coordination of Li+) and 7 (square prismatic coordination of Ba2+). The further derivatization of 1 leads to the tetratosylate (2) and the tetraazide (3), both of which have been obtained in pure form for the first time. Reduction of 3 gives the pentaamine ligand 2,6-C5H3N[CMe(CH2NH2)2]2 (4), isolated as the tetrakis(hydrobromide) salt 4 • 4 HBr. The presence of four ammonio substituents and an unprotonated pyridine nitrogen atom in the solid state has been unequivocally established by an X-ray structural analysis.


1989 ◽  
Vol 72 (6) ◽  
pp. 903-906
Author(s):  
Gracia A Perfetti ◽  
Frank L Joe ◽  
Gregory W Diachenko

Abstract A liquid chromatographic (LC) method is described for the determination of sulfite in grapes and certain grape products. Sulfite is extracted from grapes with aqueous formaldehyde solution buffered at pH 5; free sulfite is converted to hydroxymethylsulfonate (HMS), which is extremely stable at pH 3-7. Subsequent heating to 80°C for 30 min converts reversibly bound forms of sulfite to HMS. The extract is then analyzed by reverse-phase ion-pairing liquid chromatography, using a Cjg column and a mobile phase of aqueous 0.005M tetrabutylammonium ion in 0.05M acetate, pH 4.7, and a flow rate of 1 mL/min. Aqueous KOH is added to the eluate to convert HMS to free sulfite, which is then treated with 5,5'-dithiobis[2-nitrobenzoic acid]. This reaction produces the 3-carboxy-4-nitrothiophenolate anion, which is determined by measurement of electronic absorption at 450 nm. For grapes spiked with HMS at 5-20 ppm (as S02), recoveries ranged from 92 to 112%, with a coefficient of variation of 4.6%. The method was also used to determine sulfite in various grape products. Results were comparable to those obtained by the AOAC official Monier-Williams method.


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