The effect of formaldehyde on kinetics of biomass growth and consump­ tion of glucose by yeasts Candida tropicalis CC Y 29-7-33 has been inves­ tigated. For modelling of kinetics of biomass growth and consumption of the substrate the models according to Monod, Contois, and Andrews were applied. The parameters of kinetic equations were determined using the combined explicit and implicit Euler me...

In this work, a solid phase spectrophotometric method in association with flow injection analysis for formaldehyde determination has been developed with direct measurement of light-absorption in C(18) material. The 3,5-diacetyl-1,4-dihydrolutidine produced from the reaction between formaldehyde and fluoral P was quantitatively retained on C(18) support and the spectrophotometric detection was p...

Fabrication and characterization of a new amperometric chemosensor for accurate formaldehyde analysis based on platinized gold electrodes is described. The platinization process was performed electrochemically on the surface of 4 mm gold planar electrodes by both electrolysis and cyclic voltamperometry. The produced electrodes were characterized using scanning electron microscopy and X-ray spec...

quebracho tannin wood adhesive in non formaldehyde approach has low autocondensation rate and needs more press time than formaldehyde-based wood adhesives to produce wood composites. in this study, boric acid was used to increase autocondensation rate of quebracho tannin adhesive to make poplar plywood. the main ingredients of the adhesives include quebracho tannin, naoh, hexamine, boric acid a...

This study reports on a headspace gas chromatographic method (HS-GC) for the determination of formaldehyde in sanitary napkin samples. The method is based on the reaction of formaldehyde and sodium borohydride in a concentrated potassium carbonate solution (824 g/L), in which formaldehyde is quantitatively converted to methanol at 105°C in 45 min. The methanol from the conversion is determine...

an increase, even moderate, in global temperature is expected to result in a change in frequency of extreme weather events like drought, heavy rainfall and storms. the study of extreme events is difficult due to the fact that it is difficult to find long-term homogeneous data series. also the delimitation of extreme events is not univocal since a parameter value that would be defined as an extr...

Background. Imagery ability is one of the most potent factors influencing imagery effectiveness. Therefore, prior to imagery training, it is important to assess the participant’s imagery ability, typically using a self-report questionnaire. Objectives. This study examined the factorial validity and internal consistency of the Malaysian adapted SIAQ using confirmatory factor analysis and Cronba...

Formaldehyde in small quantities is commonly analyzed by spectrophotometric methods. One of the most-commonly used spectrophotometric techniques for this purpose is based on the reaction with chromotropic acid. Because of its simplicity, sensitivity, selectivity and its low cost, it is still widely used. Investigations for replacing the concentrated sulfuric acid with other acids or using more ...

In this paper, a simple dispersive liquid-liquid microextraction for the extraction and pre-concentration of formaldehyde in seawater samples followed with spectrophotometric is proposed. Formaldehyde was derivatized in situ with acetyl acetone in the presence of ammonium acetate in a single step. Then it was collected into a mixture of ethanol (disperser solvent) and chloroform (extracting...

OBJECTIVE Formaldehyde is still widely employed as a universal crosslinking agent, preservative and disinfectant, despite its proven carcinogenicity in occupationally exposed workers. Therefore, it is of paramount importance to understand the possible impact of low-dose formaldehyde exposures in the general population. Due to the concomitant occurrence of multiple indoor and outdoor toxicants, ...