Authors:Zhihan Zheng, Xiaobin Li, Fangfang Gao, Huitao Liu and Yuan Gao
/T . Determination of banned 2,4,6-trichlorophenol, pentachlorophenol and bithionol in cosmetics-High performance liquid chromatography . 2014 , 30929 . 18. Shi , L. ; Wang , J. ; Feng , J. ; Zhao , S. ; Wang , Z. ; Tao , H. ; Liu , S. J. Sep. Sci
Ionizing radiation, such as gamma-rays and electron-beams, has been applied to modify toxicity of refractory pollutants and
industrial wastewaters, however, very few studies reported the cause of toxicity changes by radiation treatment. In this work,
degradation of phenol and chlorophenols (5·10−4M) by gamma-ray treatment and consequent toxicity changes were evaluated. Toxicity of 2,4-dichlorophenol (2,4-DCP) and 2,4,6-trichlorophenol
(2,4,6-TCP) was gradually decreased with increasing absorbed dose of gamma-radiation. However, in the case of phenol and monochlorophenols
(2-, 3-, and 4-CPs), toxicity was dramatically increased particularly, for a dose of as low as 1 kGy. Hydroquinone, benzoquinone,
catechol, chlorohydroquinone, and 4-chlorocatechol were identified to be main by-products of gamma-ray treatment. From the
solid phase extraction (SPE) fractionation study, toxicity-causing by-products were found to be hydroquinone, benzoquinone,
chlorohydroquinone, and/or 4-chlorocatechol.
Authors:Hakim Faraji, Mohamad Saber-Tehrani, Afshin Mirzaie and Syed Waqif-Husain
A novel liquid-phase microextraction method coupled with high-performance thin-layer chromatography (HPTLC) for preconcentration, separation, and determination of six phenolic compounds in water samples has been developed. Target analytes were extracted using microliter volume of 1-undecanol, which floated on the surface of the aqueous sample and was separated on an RP-18 F254 HPTLC plate using a mixture of methanol-water 2:1 (%, v/v) as the mobile phase. The plates were developed vertically up to a distance of 80 mm. The calibration curves were linear in the range of 0.025–4.0 and 0.1–20.0 mg per band, with good coefficient of determinations of 0.9978–0.9991 and 0.9985–0.9995, for phenol (PN), 2-chlorophenol (2-CP), 2,4-dichlorophenol (2,4-DCP), 2,4,6-trichlorophenol (2,4,6-TCP), 2,3,4,6-tetrachlorophenol (2,3,4,6-TeCP), and pentachlorophenol (PCP). The limit of detection (LOD) and limit of quantification (LOQ) values of the six investigated compounds were between 8–35 and 25–98 ng per band, respectively. The relative standard deviations for repeatability were between 2.61% and 6.35%. The accuracy of the method was checked by the determination of recovery at three different levels, and varied from 89.21% to 101.74% with RSD% of 2.07–6.73% (n = 3).