Determination Of Aliphatic Aldehydes Research Articles

Determination of aliphatic aldehydes in maize and grass silages using on-fibre derivatisation with O-(2,3,4,5,6-pentafluoro)benzylhydroxylamine

Aldehydes and ketones are volatile compounds of silages which probably affect feed preference, palatability and intake. A sensitive and fast method was developed to determine aliphatic aldehydes in maize and grass silages. The method is based on the solid phase micro-extraction and on-fibre derivatisation of aldehydes with O-(2,3,4,5,6-pentafluoro)benzylhydroxylamine hydrochloride (PFBHA). The derivatisation agent was adsorbed onto divinylbenzene/poly(dimethylsiloxane) 65 μm fibre and then exposed to the aldehydes in the headspace of the silage samples. Aldehydes selectively react with PFBHA forming volatile oximes, which were desorbed in the injection port of a gas chromatograph and analysed by mass spectrometry. Using this method, eight aldehydes were detected in maize and grass silages being ethanal, propanal, butanal, 2-methylpropanal, pentanal, 3-methylbutanal, hexanal and heptanal, at levels ranging from tens to 200 mg/kg fresh matter. In two pilot laboratory experiments, contents of butanal and 3-methylbutanal decreased in silages prepared from grasses inoculated with Lactobacillus plantarum (1 × 10 5 CFU/g) or prepared from wilted forage.

Determination of aliphatic aldehydes by liquid chromatography with pulsed amperometric detection

An electrochemical detection method for short-chain saturated and unsaturated aliphatic aldehydes separated by liquid chromatography in moderately acidic medium is described. A triple-step waveform of the potentials applied to the polycrystalline platinum electrode, is proposed for sensitive detection of aliphatic aldehydes in flowing streams avoiding tedious pre- or post-column derivatization and/or cleanup procedures. The influences of the perchloric acid concentration and dissolved oxygen in the mobile phase, on the amperometric and chromatographic performance were evaluated and considered in terms of sensitivity and selectivity. Under the optimised experimental conditions (i.e., deoxygenated 50mM HClO4) the proposed analytical method allowed detection limits between 0.2 microM for acrolein and 2.5 microM for valeraldehyde. Regression analysis of calibration data indicates that responses for all investigated compounds are linear over about 2 orders of magnitude above the LOD, with correlation coefficients >0.990. The method was successfully applied to the determination of formaldehyde, acetaldehyde, propionaldehyde and acrolein in real matrices such as spiked water and red wines with good mean recoveries (81-97%).

Determination of aliphatic aldehydes in milk, milk products, edible fat and oil by HPLC.

乳・乳製品及び食用油脂中に含まれるアルデヒド類19成分を2,4-ジニトロフェニルヒドラジンにより誘導体化した後,HPLCを用いて高感度で精度よく測定する方法について検討した.食品からの抽出法として,エタノールを用いることによりタンパク質や油脂の除去を容易とし,迅速簡便化した.本法の検量線は0.1～5.0μg/mlで直線性を示し,検出限界は0.04～0.2μg/g,回収率71～101%,相対標準偏差は0.2～4.9%と良好であった.なお,従来法の一つであるGC法(水蒸気蒸留法)と比較した結果,回収率及び相対標準偏差とも本法が優れていた.従来から,油脂(食品)の劣化の指標としてカルボニル価や過酸化物価の測定が実施されているが,これらの方法はいずれも食品から油脂の抽出操作が必要となり,煩雑で時間を要する.本法は油脂の抽出操作を必要とせず,直接アルデヒド類を個別に測定できる方法であり,食品の変質(酸化)の程度を判定する上で有用と考える.

Determination of Aliphatic Aldehydes C1—C4in Waste Gas by HPLC

Abstract A simple and rapid method for the determination of aliphatic aldehydes (C1—C4) in waste gas was developed. Sample collection and derivatization are performed directly in a sorption tube containing Chromosorb P impregnated with 2,4—dinitrophenylhydrazine and catalyst. This methods allows direct injection of a methanol extract of a sorption tube into a chromatograpiiic column. Detection limit of aldehydes is below 1 mg/m for a 10 1 sample. The technique was used to measure aldehyde emissions from wood fired furnace.

Determination of aliphatic aldehydes in waters by high-performance liquid chromatography

A method is described for the determination of linear aldehydes (C 1–C 8) in waters. Aldehydes are extracted into n-pentane after derivatization with 2,4-dinitrophenyhydrazine and quantified by reversed-phase high-performance liquid chromatography with detection at 365 nm. With a 250-ml sample, the limit of detection is 1 μg l −1 for the C 1–C 8 aldehydes. The method is directly applicable to surface waters and drinking water. Analysis of different surface waters, treated water and a humic acid solution after ozonization showed that C 1–C 3 aldehydes predominated, their concentration increasing with increasing ozone dosage.

Determination of aliphatic aldehydes in air by liquid chromatography

Utilisation de cartouches de Sep-PAK C 18 impregnes de dinitro-2,4 phenylhydrazine et d'acide phosphorique pour l'echantillonnage. Analyse des aldehydes aliphatiques de C 1 a C 4 dans l'atmosphere, les emissions industrielles et les emissions d'incinerateur

Determination of aliphatic aldehydes in aqueous solution by chemiluminescence measurements

The determination of aliphatic aldehydes (5 × 10 -6 — 2.5 × 10 -4 mol) in aqueous solution was achieved by inhibition of the luminol chemiluminescence induced by hydrogen peroxide in the presence of potassium hexacyanoferrate(III).

The Gas Chromatographic Analysis of the Digestion Gases and the Offensive Compounds Produced in the Process of the Night Soil Treatments

In this paper, the gas chromatographic analysis of the offensive components in the night soil treatment plants was carried out at Funaigun Plant in Kyoto Prefecture, Toyonaka & Itami Plant, Neyagawa Plant and Takatsuki Plant in Osaka Prefecture, where the anaerobic digestion method has been employed.The results of the investigation were as follows:1) The gases in the digestion tanks contained 20.6 to 27.4% CO2, 51.7 to 66.0% CH4 and 0.9 to 2.0% O2. The gases in the tightly sealed trickling filter contained 15.0% CO2, 30.4% CH4 and 20.4% O2.2) The determination of aliphatic amines, ammonia, hydrogen sulfide was carried out using the Triton X-100 and Quadol column after the samples were collected into the distilled water. Total amines (40.2 to 61.0ppm), ammonia (440 to 1, 220ppm) and hydrogen sulfide (3, 180 to 8, 060ppm) were found in the digestion tanks.3) The determination of aliphatic aldehydes and ethanol was carried out using Tricresyl Phosphate+Polyethylene Glycol and Ucon oil 50HB column. The concentration of total aldehydes was 16.6 to 25.0ppm and ethanol was 38.8 to 46.6ppm in the digestion tanks.4) The determination of lower aliphatic mercaptans and thioether was carried out using Tricresyl Phosphate and Ucon oil 50HB column. The concentration of total mercaptans and thioether was 8.6 to 12.0ppm in the digestion tanks.5) The determination of indol and skatol was carried out using Silicon DC HV grease and Silicon KF-96 column, after they were collected into benzene. The total amount of indols was 6.1 to 21.5×10-2ppm.6) A tentative method to evaluate the intensity of offensive odor was proposed. The ratio of the observed values to the olfactory thresholds was calculated for each offensive component. It was 104 to 105 for marcaptans and skatol, and was 103 for hydrogen sulfide. But the ratio for ammonia was found very low.From these results, it might be suggested that mercaptans and skatol in the digestion tanks have large effects but ammonia has little effcts to the human olfaction.

Determination of Aliphatic Aldehydes by Spectrophotometry.

Determination of Aliphatic Aldehydes by Spectrophotometry.

The 3-Methyl-2-benzothiazolone Hydrazone Test. Sensitive New Methods for the Detection, Rapid Estimation, and Determination of Aliphatic Aldehydes

The 3-Methyl-2-benzothiazolone Hydrazone Test. Sensitive New Methods for the Detection, Rapid Estimation, and Determination of Aliphatic Aldehydes