Method For Determination Of Phenol Research Articles

Selected Phenolic Compounds in Mainstream Cigarette Smoke, CORESTA Collaborative Study and Recommended Method *

SUMMARY A collaborative study among 20 participating laboratories was conducted in an effort to publish a recommended method for determination of phenols in mainstream cigarette smoke. The study was conducted using 10 test samples including reference cigarettes and commercial products from various regions (ISO 3308 total particulate matter 1–16 mg/cig) smoked under two regimes (ISO 3308 and ISO 20778). Health Canada method T-114 was chosen as a basis for the analytical methodology and therefore mainstream cigarette smoke was trapped on 44-mm glass fiber filter pads which were subsequently extracted with 1% aqueous acetic acid for analysis by high performance liquid chromatography with fluorescence detection. Statistical analysis was carried out following ISO 5725 to generate repeatability (r) and reproducibility (R) data for results from linear and rotary smoking. For reproducibility (R) expressed as a percentage of mean yield across all of the studied products and both smoking regimes, values ranged from 17–150%. The lowest “tar” yielding products had the most variable data. Results trended as expected for total particulate matter, blend type, regime, and relative analyte yields. Results supporting a robust method for hydroquinone, resorcinol, catechol, phenol, o-cresol, m-cresol, and p-cresol are reported herein and support establishment of CRM 78, ISO 23904 and ISO 23905 standardized methods. [Contrib. Tob. Nicotine Res. 32 (2023) 18–25]

Development and Validation of a Gas-Chromatographic Method for Quantitative Determination of Phenol in Biologicals

A gas-chromatographic method for quantitative determination of phenol in biological drugs was developed. The optimal chromatography conditions were a DB-WAX column (30 m × 0.25 mm × 0.25 μm, Agilent Technologies); injector temperature 250°C; split ratio 40:1; sample volume 0.5 μL; He carrier gas; constant pressure mode; flow rate 1.4 mL/min; furnace temperature profile: initial 160°C (constant for 3 min), ramp at 40°C/min to 200°C (constant for 0.6 min), ramp at 40°C/min to 220°C; analysis time 7.133 min; and detector temperature 250°C. The method was validated. The analytical range of the method was phenol concentrations from 1 to 5 mg/mL. The accuracy and specificity of the method were confirmed. The precision was evaluated. The results allowed this method to be considered an alternative for quantitative determination of phenol in biologicals.

A novel flow injection chemiluminescence method for automated and miniaturized determination of phenols in smoked food samples

An easily performed fully automated and miniaturized flow injection chemiluminescence (CL) method for determination of phenols in smoked food samples has been proposed. This method includes the ultrasound assisted solid-liquid extraction coupled with gas-diffusion separation of phenols from smoked food sample and analytes absorption into a NaOH solution in a specially designed gas-diffusion cell. The flow system was designed to focus on automation and miniaturization with minimal sample and reagent consumption by inexpensive instrumentation. The luminol – N-bromosuccinimide system in an alkaline medium was used for the CL determination of phenols. The limit of detection of the proposed procedure was 3·10−8·molL−1 (0.01mgkg−1) in terms of phenol. The presented method demonstrated to be a good tool for easy, rapid and cost-effective point-of-need screening phenols in smoked food samples.

Development of Simultaneous HPLC-Fluorescence Assay of Phenol and Chlorophenols in Tap Water after Pre-Column Derivatization with 3-Chlorocarbonyl-6,7-dimethoxy-1- methyl-2(1<i>H</i>)-quinoxalinone

Chlorophenols (2-chlorophenol, 4-chlorophenol, 2,4-dichlorophenol, 2,6-dichlorophenol and 2,4, 6-trichlorophenol) may be presented in natural waters or drinking water as a result of disinfection processes involving chlorination, or as contaminants derived from domestic products, industrial operations and agricultural chemicals. A previous HPLC-UV method for determination of phenol and five chlorophenols in tap water using 4-fluoro-7-nitro-2,1,3-benzoxadiaole as a UV labeling reagent shows limited sensitivity. Here, we present an improved HPLC-fluorescence detection method for simultaneous determination of phenol and the above chlorophenols in tap water after pre-column derivatization with 3-chlorocarbonyl-6,7-dimethoxy-1-methyl-2(1H)-quino- xalinone (DMEQ-COCl), using a short, narrow column (50 × 2.1 mm i.d., packed with 5 μm particles of C18 material) to improve the sensitivity. Standard samples containing the compounds are derivatized with DMEQ-COCl in borate buffer (pH 9.0) at room temperature for 3 mins. The response is linear in the concentration range of 0.01 - 0.05 to 0.5 mg/L with r2 values ≥0.9967 for all compounds. The lower limits of detection are 0.001 to 0.008 mg/L, and the coefficients of variation are less than 8.8%. The recovery values from tap water spiked with standard samples are satisfactory. The present method is suitable for examining whether or not tap water samples are contaminated with phenol and chlorophenols in excess of regulatory values.

GC/MS를 이용한 식품 중 페놀 분석

The present study demonstrated the development and validation of the method for the quantification of phenol in food using gas chromatography coupled with mass spectrometry (GC-MS). After spiking of interanl standard (Phenol-d 5 ) to food, those samples were extracted with organic solvent mixture (acetone : dichloromethane = 1 : 1, v/v) using ultra sonic extractor and cleaned by gel permeation chromatography (GPC) technique. The amount of phenol was determined by GC/MS. To validate the developed method, we evaluated parameters were the selectivity, linearity, accuracy, precision, and recovery. To demonstrate the selectivity of the method, blank samples of rice, corn, and fish(mackerel) were prepared and subjected to GC-MS analysis. To verify the linearity of the method, six different standard concentrations of phenol at 0.01, 0.05, 0.1, 0.5, 1 and 2.5 mg/kg were evaluated. The correlation coefficient (r) of calibration curve was 0.9999. The recovery rate for phenol standard calculated by internal standard method were 82.2~101.5% for samples fortified with 0.25, 0.50, and 1.0 mg/kg, respectively. Also the repeatability and reproducibility for validation of precision were 0.2~5.5%. According to the result of the validation, this established method was suitable for AOAC guideline. The limit of detection (LOD) for phenol analysis were 0.03~0.1 mg/ kg, and the limit of quantification (LOQ) were 0.1~0.3 mg/kg. Therefore, we established the optimal analysis method for determination of phenol in food using GPC and GC/MS.

Determination of phenol, m-cresol and o-cresol in transformer oil by HPLC method

Paper and mineral transformer oil are the major insulating materials used in transformers. Besides them, various materials are used for insulation or construction purposes like hard paper, laminated wood, rubber, resins, coatings, adhesives and other. These materials are in contact with the oil, due to thermal and electrical stresses they degrade and finally breakdown, producing gaseous, liquid and solid degradation products. The degradation products are partly soluble in the oil and partly excreted in the form of sludge. Some degradation products are characteristic for specific materials, so-called markers, like furans for cellulose, phenol and cresols for phenolic resins. It was confirmed that phenol, m-cresol and o-cresol are not present in new oils and that their presence may indicate degradation of insulation material. Samples of laminated pressboard and laminated wood were exposed to accelerated ageing tests to confirm the origin of phenol, m-cresol and o-cresol in transformer oil.The paper describes the method for determination of phenol, m-cresol and o-cresol in transformer oil by a high performance liquid chromatography (HPLC). Sample preparation by liquid–liquid extraction, compound separation in a single run and detection with a photo diode array detector are also described.Detection of phenol, m-cresol and o-cresol in transformer oil from operating transformers by HPLC technique provides an additional diagnostic tool for assessing normal or abnormal condition of transformer insulation, and presents a complementary technique to dissolved gas analysis.

Simultaneous determination of and in wastewater using near-infrared diffuse reflectance spectroscopy with adsorption preconcentration.

Near-infrared diffuse reflectance spectroscopy (NIRDRS) has been proven to be a convenient and fast quantitative method for complex samples. A method for simultaneous quantitative determination of phenol and p-nitrophenol in wastewater was developed by using NIRDRS with a preconcentration procedure of resin adsorption. In the method, the analytes were firstly adsorbed onto the adsorbent, and then the NIRDRS spectrum of the adsorbent was measured for quantitative analysis by partial least squares (PLS) regression. The results show that the two phenolic compounds can be immobilized onto the adsorbent and directly measured by NIRDRS. The correlation coefficients (R) between the reference values and prediction results for phenol and p-nitrophenol were 0.958 and 0.957, respectively. Furthermore, the interferences of the coexistence components can be eliminated with the aid of multivariate calibration. The method may provide a sensitive, effective and fast way for simultaneous quantitative analysis of phenol and p-nitrophenol in solution samples.

A direct Capillary Liquid Chromatography with electrochemical detection method for determination of phenols in water samples

A fast and direct method based on the use of Capillary Liquid Chromatography (LC) with electrochemical (EC) detection has been described for phenols pollutants in water samples. Concretely, phenol, o-cresol, 2-chlorophenol and bisphenol A have been selected as target analytes. The combination of Capillary LC with EC detection avoided the necessity of preconcentration steps typically used in environmental analysis. The sample injected volume was 2 μL. The achieved detection limits were between 1 and 2 μg/L and the linear dynamic range was up to 50 μg/L for all studied phenols. The precision and uncertainty were satisfactory. The analysis time per sample was 10 min. The proposed procedure has been proved useful for treated waters.

A Novel Liquid-Liquid Microextraction Based on Solidification of Floating Organic Droplet Method for Determination of Phenols in Aqueous Samples

Pre-concentration and determination of 7 phenolic compounds in water samples has been achieved using a new liquid-liquid microextraction coupled HPLC-DAD. Microextraction efficiency factors have been investigated and optimized: 14 µL 1-undecanol micro drop exposed for 15 min floated on surface of a 20 mL water sample at 55°C, stirred at 1200 rpm, low pH level and saturated salt conditions. Under the selected conditions, limit of detection of 0.5- 3.0 µg L -1 (S/N=3) and linearity range of 0.3-870 µg L -1 have been obtained. A reasonable repeatability (RSD ≤ 10.1%, n=5) with satisfactory linearity (0.9992 ≥ r 2 ≥ 0.9973) of results illustrated a good performance of the present method. The relative recovery of different natural water samples was higher than 84%.

Adsorptive Stripping Voltammetric Determination of Phenol at an Electrochemically Pretreated Carbon-Paste Electrode with Solid Paraffin as a Binder

An adsorptive stripping voltammetric method for determination of phenol at an electrochemically pretreated carbon-paste electrode has been developed. Solid paraffin was used as the binder of the carbon-paste electrode. The carbon-paste electrode was pretreated in the solution of 0.001 mol L−1NaOH by holding it at +1.8 V (versus an Ag/AgCl electrode) for 5 min. On the pretreated electrode, the adsorption of phenol was greatly enhanced. Phenol was accumulated in NH3–NH4Cl (pH 9.25) medium at the potential of +0.1 V (versus Ag/AgCl electrode) for a certain time and then determined by second order differential anodic stripping voltammetry. An oxidative peak was observed at about +0.66 V. The relationship between second order peak current and phenol concentration was linear in the range of 2.5 × 10−7–5.0 × 10−6mol L−1phenol, and the detection limit was 5.0 × 10−8mol L−1. The method has been applied to the determination of phenol in tap water and waste water. The relative standard deviation (six determinations) was less than 3.5%.

HPLC Method for Determination of Phenol in River and Waste Water

Abstract A method is proposed for the determination of phenol in river and waste water using electrochemical detection HPLC. An octadecyl silica solumn was used with a gradient of methanol in water from 40 % to 100 %. With preconcentration unit (guard C 18 column) on line and ampermetric detection (+1.1 V), detect-ability limit at 30 ppt was achieved. The method has been applied for the control of the performance of the purification plant.

Analytical comparison of an enzyme-amperometric method for chlorocresol determination in ointments with colorimetry and liquid chromatography

The direct determination of chlorocresol in n-hexane extracts of commercial ointments was successfully performed using an enzyme-amperometric probe for analysis of phenols and working in previously characterized and optimized non-aqueous solvents. The analytical data obtained were compared with those found by using classical HPLC or chemical spectrophotometric method for determination of phenols.

Colorimetric Determination of Phenols in Water Samples

A colorimetric method for determination of phenols in water has been developed. The method, which is a modification of Liebermann's reaction, uses resorcinol as a chromogenic agent. The developed method is more sensitive, and the difficulties encountered in the widely used 4-aminoantipyrine method have been avoided. Application of both the proposed and 4-aminoantipyrine methods to the analysis of natural and tap water samples are presented.

An improved distillation apparatus for a continuous flow method for the determination of phenol in wastewater

A distillation apparatus for a continuous-flow method for determination of phenol in water is described. The colorimetric measurement step utilizes the familiar 4-aminoantipyrine method. Phenol in water can be measured at a rate of 10 samples per hour, has a sensitivity of 4.0 × 10 3 μg l −1 per unit absorbance, a limit of detection of 5 μg l −1, and a standard deviation of 1.6 μg l −1 for 20 replicates of a 100-μg l −1 sample.

A kinetic study of the oxidation of phenols and chlorophenols by metaperiodate

The fixed-time kinetics of oxidation of phenol and di-, tri-, and tetra-chlorophenols by metaperiodate in acidic solution is assessed as a method for determination of phenols in the 50–500 mg l −1 concentration range in aqueous media. The effects of temperature and of acid and periodate concentration on the reaction kinetics are described.

Rapid method for determination of phenols

Rapid method for determination of phenols