Wyniki wyszukiwania - Biblioteka Nauki

1

Development of an innovative gas chromatography-mass spectrometry method for assessment of formaldehyde in the workplace atmosphere

100%

Dugheri S. , Bonari A. , Pompilio I. , Colpo M. , Mucci N. , Montalti M. , Arcangeli G.

Acta Chromatographica

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2017

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tom Vol. 29, no. 4

511--514

EN

World consumption of formaldehyde (FA) is forecast to grow at an average annual rate of about 4% from 2015 to 2020 with world production to exceed 52 million tons in 2017. From the first day of January 2016, the Commission Regulation No. 91/2015 established the FA classification through an indication from European Chemical Agency as category 2 mutagenic and category 1B carcinogen. A novel method for the determination of gaseous FA in air is presented herewith. The sampling was carried out using a miniaturized cartridge by means of a medium-flow pumping system (1.0 L min-1, 5–60 min) and absorption of FA vapors on 2,4-dinitrophenylhydrazine. Cartridge desorption removing the excess derivatizing agent based upon solid-phase extraction was performed by an innovative xyz robotic system on-line with fast gas chromatography (GC)—mass spectrometry (MS). Through the generation of standard atmospheres of known concentration of FA, we evaluated the precision (relative standard deviation for n = 10, 8.8%), lower limit of quantification (0.072 µg/cartridge), and linearity (from 0.125—64 µg/cartridge with correlation coefficient of 0.99) of the method. The described procedure combines the efficiency of fast GC—MS systems with both the high throughput of autosampler and the quantitative accuracy of FA-dinitrophenylhydrazone for measuring American Conference of Governmental Industrial Hygienists TLV Ceiling.

2

Vibrational calculations in formaldehyde: the CH stretch system

100%

Rashev S. , Moule D.

Open Chemistry

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2011

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tom 9

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nr 4

549-556

EN

An alternative procedure for the calculation of highly excited vibrational levels in S0 formaldehyde was developed to apply to larger molecules. It is based on a new set of symmetrized vibrational valence coordinates. The fully symmetrized vibrational kinetic energy operator is derived in these coordinates using the Handy expression [Molec. Phys. 61, 207 (1987)]. The potential energy surface is expressed as a fully symmetrized quartic expansion in the coordinates. We have performed ab initio electronic computations using GAMESS to obtain all force constants of the S0 formaldehyde quartic force field. Our large scale vibrational calculations are based on a fully symmetrized vibrational basis set, in product form. The vibrational levels are calculated one by one using an artificial intelligence search/selection procedure and subsequent Lanczos iteration, providing access to extremely high vibrational energies. In this work special attention has been given to the CH stretch system by calculating the energies up to the fifth CH stretch overtone at ∼16000 cm−1, but the method has also been tested on two highly excited combination levels including other lower frequency modes. [...]

3

Effect of increasing graded doses of formaldehyde on human embryonic kidney cells

100%

Banerjee A. , Dholey M. , Mukherjee S. , Maji, B.K

Progress in Health Sciences

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2018

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tom 8(1)

36-45

EN

Purpose: In the present study, we aimed to identify the effect of three increasing doses of most widely preservative, formaldehyde (FA) on the urinary system using human embryonic kidney cells (HEK-293) in vitro. Materials and methods: The HEK-293 cells were grown in Dulbecco’s Modified Eagle medium (DMEM, Gibco, USA) supplemented with 10% of fetal bovine serum, 100 IU/ml penicillin and 100 μg/ml of streptomycin (Gibco, USA) using 25cm2 flasks (Nunc, Denmark), in a CO2 incubator (Heal Force) at 37°C are treated with 19 % formaldehyde in DMEM supplemented with 10% of fetal bovine serum to yield final concentrations of 0.05 μl/ml, 0.1 μl/ml, 0.5 μl/ml and 1.0 μl/mlof 19% FA. Results: The result showed that statistically significant dose dependent decrease in cell viability of HEK-293 cells with exposure to increasing concentration of FA (0.05 μl/ml, 0.1 μl/ml, 0.5 μl/ml and 1.0 μl/ml) on MTT assay. Extremely huge dose dependent DNA damage with a dose dependent up regulation of mRNA expression of pro-apoptotic iNOS and TNF- gene was observed when HEK-293 cells are treated with the increasing concentration of FA. In addition, the protein expression levels of Bcl-2 and Bax revealed that increasing concentration of FA on HEK-293 cells down regulated the anti-apoptotic Bcl-2 and up regulated pro-apoptotic Bax gene. Conclusions: Our result indicates that, high dose of FA is more dangerous than the low dose on HEK-293 cells with cellular damage.

4

Determination of formaldehyde and cyanide ion in human nasal discharge by using simple spectrophotometric methods

88%

Narkowicz S. , Polkowska Ż. , Namieśnik J.

Open Chemistry

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2013

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tom 11

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nr 1

16-24

EN

Environmental tobacco smoke (ETS) contains many toxic compounds which include substances classified as aldehydes (e.g. formaldehyde) and inorganic substances such as cyanide ions. The information on the determination of these compounds in water is available, but the monitoring data on the level of these substances in human body fluids are still lacking. In this work the procedure for determining cyanide ions and formaldehyde in samples of human nasal discharge by simple spectrophotometric technique is presented.

5

Health risk assessment of exposure to formaldehyde in dental materials

75%

Lyapina M. , Krasteva A. , Dencheva M. , Tzekova M. , Deliverska M. , Kisselova-Yaneva A.

Open Medicine

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2014

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tom 9

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nr 2

332-338