Recovery Of Pentachlorophenol Research Articles

Development of a highly sensitive ELISA and immunochromatographic strip to detect pentachlorophenol

ABSTRACTA sensitive monoclonal antibody for targeting pentachlorophenol was prepared with an immunization procedure and cell fusion. The antibody was characterized with an indirect competitive enzyme-linked immunosorbent assay (ELISA), which had an IC50 of 0.2 ng/ml for pentachlorophenol under optimized conditions. The cross-reactivity of the ELISA to related compounds was very low. The recovery of pentachlorophenol was 99.2–105% in water samples and 89–110.9% in fish samples. A simple, rapid, and sensitive immunochromatographic strip was produced based on the monoclonal antibody, with a qualitative visual limit of detection of 2 ng/ml in water samples and 10 ng/ml in fish samples, indicating its potential utility in monitoring pentachlorophenol in the field.

Determination of Water- and Methanol-Extractable Pentachlorophenol in Soils Using Vortex-assisted Liquid-Liquid Extraction and Gas Chromatography

Abstract An analytical procedure for determination of water- and methanol-extractable pentachlorophenol (PCP) in soils was developed using vortex-assisted liquid-liquid extraction (VALLE) and gas chromatography (GC). Significant extraction parameters such as vortex speed and liquid-liquid volume ratio were optimized for extracting PCP from solution. The recovery of PCP was the highest (97.4%) with good reproducibility and a small relative standard deviation (RSD, 0.5%) when the vortex speed was at 2000 rpm. Meanwhile, when the volume ratio of derivatization solution to n-hexane was at 10:4, the recovery of PCP was 103% with a RSD of 0.7%. The linearity of the calibration curve for PCP determination ranged from 1.25 μg L−1 to 4000 μg L−1, with a correlation coefficient (R2) of 0.9999. The detection limit of PCP in water samples was below 0.2 μg L−1 and the measuring range was relatively wide, and suitable for trace- and micro-analysis of PCP. Compared with traditional extraction methods (liquid-liquid and solid-phase), VALLE consumes less extractant, requires fewer steps, and achieves higher recovery (96.8%) and smaller RSD (3.7%). The reliability of VALLE was verified in four distinct types (paddy, red, black and alluvial) of soil samples spiked with 1 and 10 mg kg−1 PCP. The total recoveries of PCP in the soil samples were in the range of 89.5%–98.9% by water extraction and 88.7%–98.4% by 3 consecutive extractions with methanol in a sequential procedure. The results indicated that VALLE-GC satisfied the requirements for extracting and determining water- and methanol-extractable PCP in soils polluted by PCP at varying levels.

Recovery of Pentachlorophenol from Aqueous Solution via Silicone Rubber Membrane

Although pentachlorophenol (PCP) has been widely employed as a biocide for over 60 years, its production and use are currently severely curtailed in many countries due to its extreme toxicity. In recent years, the contamination of both soil and surface waters by PCP has become a concern. In this study the permeation characteristics of PCP penetrating silicone rubber membranes (SRM) were studied, in order to determine the feasibility of separation of PCP from water via the permeation and chemical desorption (PCD) method. It was found that efficient separation and recovery of PCP could be obtained using an acidic feed solution and an alkaline recovery solution. The permeation rate of PCP into the SRM was optimized when the feed solution was maintained at a pH of 4 or lower. The SRM thickness did not significantly affect the permeation rate, indicating that the rate determining step for the process is the initial movement of the PCP into the SRM. The activation energy for the penetration process was determined to be quite high, and thus thermal controls will play an important role in the recovery of PCP by this method. The membrane distribution coefficient (mc) for PCP moving into SRM was large and showed a strong correlation to permeation rates reported previously, confirming that PCD is a suitable technique for the separation and recovery of PCP from aqueous solution.

Development of an enzyme-linked immunosorbent assay for the detection of pentachlorophenol residues in water samples

An indirect competitive enzyme-linked immunosorbent assay (ELISA) for pentachlorophenol (PCP) was developed with a polyclonal antiserum produced against a hapten, 4-(2,3,5,6-tetrachloro-4-hydroxyphenoxy)-butyric acid, conjugated to bovine serum albumin (BSA). The ELISA of PCP showed an IC50 of 18 ng/ml and a limit of detection (LOD) of 0.9 ng/ml at the optimal concentration of NaCl (0.2 M) in the assay buffer. This assay was slightly affected by up to 10% (v/v) methanol or acetone. The IC50 and A max values showed little change in a pH range of 5 and 7. Very low cross reactivities (≤2.5%) were observed for some structurally-related compounds, except for 2,3,4,6-tetrachlorophenol (5.6%) and 2,3,5,6-tetrachlorophenol (9.2%). The average recoveries of PCP from fortified water were in the range of 71–118%. The results by GC and ELISA for the same fortified water samples showed non-significant difference (p>0.05). Finally, this ELISA was applied to monitor PCP in 100 river water samples and no PCP was detected. This ELISA is a good alternative tool for monitoring PCP residues in water samples.

Gas chromatographic methods for monitoring of wastewater chlorophenol degradation in anaerobic reactors

Wastewater samples from an anaerobic reactor were extracted with hexane and derivatized with diazomethane (method 1) and with acetic anidride (method 2). Gas chromatography with electron-capture detection (ECD) was employed for separating the parent compound and intermediates trichlorophenols (TCP) and dichlorophenols (DCP) which originated from the penta chlorophenol (PCP) degradation process. The relations between concentrations of PCP, TCP and DCP areas were linear in the range of concentrations of 0.2 to 8 mg/L and 0.025 mg/L to 5 mg/L for methods 1 and 2, respectively. The repeatability of the extraction methods was satisfactory, with variation coefficients lower than 11%. For method 1, at the fortification level of 0.2 mg/L, recovery of PCP, TCP, and DCP was 112%, 74% and 45%, respectively. For method 2, the corresponding recovery values at the fortification level of 0.1 mg/L were 91%, 93% and 103%, respectively. Storage of the frozen samples did not alter their PCP determination properties. The chromatographic methods adapted for chlorophenol determination in wastewater were suitable with relatively simple manipulation techniques. The obtained results were reproducible and allowed identification of intermediates formed during the PCP degradation process.

Cetyltrimethylammonium Bromide as a Regulator in Paper Separation of Pentachlorophenol Herbicide and Methyl Orange Dye

AbstractAn experimental investigation is presented for separation of pentachlorophenol (PCP) and methyl orange (MO) from an aqueous solution by use of cetyltrimethylammonium bromide (CTAB) as a regulator in the paper capillary permeation adsorption process (PCPA). The effects of pH, concentration of CTAB, and ionic strength on the separatability of the molecules were studied. The maximum separatability of nearly 100% PCP and MO was obtained in the optimum pH range 5–11 and 7–11, respectively. The ionic strength has an appreciable effect on separatability. The recovery of PCP and MO from paper by elution with acetone: isooctane solvent gradients was also studied. The selective separation of PCP and MO admixed in aqueous solution by a developed solvent elution technique was also reported. It was believed that PCP and MO were separated as their ion pairs with CTA cations by adsorption on the fiber surface.

A Novel Laboratory Microcosm for Cocomposting Of Pentachlorophenol Contaminated Soil

A bench-scale composting system was constructed that relied on heat generation by microbial activity in the material rather than extraneous incubation. The system gave reproducible composting temperatures and eight microcosms could be operated simultaneously. These systems were used to investigate the feasibility of cocomposting pentachlorophenol (PCP) contaminated soil as a bioremediation strategy. Laboratory cocomposting of the contaminated soil successfully reduced PCP concentrations by 80%, from 68 mg/kg to 11 mg/kg in a six-week period. Losses of PCP from compost controls were minimal indicating that removal was due primarily to biotic processes. A comparison of residual PCP levels determined by dichloromethane (DCM) extraction and a methanolic potassium hydroxide (MeOH/KOH) digest prior to DCM extraction suggested that the residual PCP was bound to the compost matrix. Recovery of PCP at the end of a composting experiment using eight vessels simultaneously using the MeOH/KOH method indicated residual concentrations of 8-10 mg/kg.

Determination of Pentachlorophenol (PCP) in Samples of the Environmental Specimen Bank Using Isotope Dilution

Within the program of the Environmental Specimen Bank a quick and efficient method for determination of pentachlorophenol (PCP) in various environmental matrices has been developed. The method includes alkaline hydrolysis of bound PCP, acidification, simultaneous steam distillation and extraction in one glass apparatus. After clean-up and derivatization with acetic anhydride the samples were analyzed by gas chromatography/mass spectrometry. Concentrations were calculated using 13C-labeled PCP as the internal standard. Validation was carried out with various environmental samples (soil, fish, conifer needles, kale). The method can be used for various biological samples without any modification. The extracts are free of matrix components (lipids, chloropyll, terpenes, etc.) and other contaminants, which results in clear chromatograms with few peaks; therefore, correct integration is facilitated. Although the recoveries of PCP are in the range of 50–90%, due to losses during the several method steps, these losses can be corrected with the 13C-labeled internal standard, resulting in high precision (1.5–2.2% standard deviation).

Effect of Hydrochloric Acid on Sampling and Analysis of Semivolatile Organic Compounds in Incineration Flue Gas. 1. Chlorophenols

The recoveries of 16 isomers of chlorophenols (CPs) from the adsorbent (XAD-2) of the MM5 train are affected by hydrochloric acid (HCl) present in the incinerator flue gas. At 2.05 and 5.53 mg/L in flue gas, HCl caused desorption of CPs from XAD-2. The desorption is dependent upon the number of chloro substituents in the CPs. The Soxhlet extraction behaviors of CPs from XAD-2 in the presence or the absence of HCl were also studied in the laboratory. The results explain the previously reported low recovery of pentachlorophenol from XAD-2 when the flue gas contained none or very low concentrations of HCl. An extraction procedure for complete CPs recoveries from XAD-2 is proposed that involved two sequential extractions: first with dichloromethane and then with the addition of 1.0 mL of 1.0 M aqueous HCl on XAD-2 and followed by the subsquent extraction with dichloromethane. This procedure does not affect other semivolatile compounds on XAD-2 and leads to [13C6]pentachlorophenol surrogate recovery of 90 ± 6...

Gas Chromatographic Determination of Pentachlorophenol in Gelatin: Collaborative Study

Eleven collaborators participated in this study of a gas chromatographic method for the determination of pentachlorophenol (PCP) in gelatin. Following acid hydrolysis of a 2 g sample, PCP is extracted with hexane and partitioned into KOH solution. After reacidification, PCP is again extracted with hexane for determination by electron capture gas chromatography on a 1% SP-1240DA column. Three duplicate practice samples (0.0, 0.5, and 1.5 ppm) and 5 blind duplicate collaborative samples (0.0, 0.02, 0.1, 0.5, and 2.0 ppm) were analyzed by each collaborator. Mean recoveries of PCP in the collaborative samples ranged from 88% at the 0.02 ppm fortification level to 102% at the 0.1 ppm level; the overall mean recovery was 96%. Interlaboratory coefficients of variation ranged from 16.4% for the 0.1 ppm fortification level to 22.9% for the 0.5 ppm level; the overall interlaboratory coefficient of variation was 19.5%. The method has been adopted official first action.

Analytical Method of Pentachlorophenol in Wooden Chips

A method for the determination of pentachlorophenol (PCP) in wooden chips was investigated.PCP was distilled with steam and extracted with n-hexane from acidified distillate. PCP in n-hexane was extracted with 0.1M sodium carbonate solution and then acetylated with acetic anhydride. PCP acetate was extracted with n-hexane and purified by silica gel column chromatography. The eluate was analyzed by gas chromatography using an electron capture detector.Acetyl derivative of PCP gave heigher recorder response than free PCP.The recovery of PCP from PCP added wooden chips was 98.4%.

Excretion and Tissue Distribution of Uniformly Labeled 14C-Pentachlorophenol in Rats

The excretion and tissue distribution of pentachlorophenol were studied in rats by administration of oral doses of 99.5% radiochemically pure, uniformly labeled 14C-pentachlorophenol dissolved in olive oil. After oral administration, less than 0.04% of the administered radioactivity was detected in the respired air in a 24-hr. period. The recovery of pentachlorophenol and/or metabolites in the urine was greatest at the 16-hr. collection period. The average total percent of the administered activity recovered in the urine after 24hr. was 50.2%, with between 9.2 and 13.2% being recovered in the feces after 10 days. The tissues containing the highest levels of activity were the liver, kidney, and blood, respectively. All other tissues contained less activity than the blood.