Certification of reference materials for the determination of alkylphenols.

Certified reference materials (CRMs) are playing an increasingly important role in national and international standardizing activities. In Japan, primary standard solutions for analyses of endocrine disrupters are supplied under the national standards dissemination system named the Japan Calibration Service System (JCSS). For the traceability on reference materials used for preparation of the primary standard solutions based on the JCSS, the National Metrology Institute of Japan, National Institute of Advanced Industrial Science and Technology (NMIJ/AIST) has developed and certified high-purity reference materials of alkylphenols as NMIJ CRMs, such as 4-n-nonylphenol, 4-tert-octylphenol, 4-n-heptylphenol, 4-tert-butylphenol, and 2,4-dichlorophenol. Thereafter, it is essential to determine the alkylphenols by using these solutions based on the JCSS for environmental monitoring and risk assessments because analytical values obtained by using the solutions can ensure the reliability and traceability of the chemical analyses.

Ecotoxicity of chlorophenolic compounds depending on soil characteristics.

Three chlorophenolic compounds (2-chlorophenol, 2,4,6-trichlorophenol, and pentachlorophenol) were tested to assess their effects on two soils with different properties: a granitic soil (Haplic Arenosol) and a calcareous one (Calcaric Regosol). Different concentrations of the pollutants (ranging from 0.001 to 10,000 mg kg(-1) soil, d.w.) were assayed for their effects on soil microbial activity and composition, using manometric respirometry and PCR-DGGE analysis, respectively. Other ecotoxicity tests such as Lactuca sativa seedling growth in the contaminated soils and algal growth inhibition (Pseudokirschneriella subcapitata) in their water extracts were done. The behaviour of the pollutants in the soils with respect to biodegradability and volatilization was also investigated. In the Haplic Arenosol, volatilization is the main process affecting 2-chlorophenol. Degradation and fixation of this compound in the soil matrix are favored in the Calcaric Regosol. This is the least toxic pollutant assayed. For 2,4,6-trichlorophenol, the soil pH is a critical parameter in the toxicity assays due to the neutral pKa of the compound. It is toxic in the soil microbial activity assay, but some recovery of the biotic processes can be observed, particularly in the Calcaric Regosol. This compound is more toxic in the Haplic Arenosol than in the Calcaric Regosol. Pentachlorophenol is ionized in both soils due to its low pKa, increasing its water solubility. It is highly toxic to the soil microbiota, thus inhibiting respiration, biodegradation and other biotic dissipation processes. Plant and alga tests, were more sensitive than soil microbial tests, except for PCP. The microbial populations tend to show changes at lower concentrations than the microbial activity. Some soil types (abundant in the Mediterranean area), with alkaline pH and fine textures could show higher level of ecotoxicity for ionizable organic pollutants than the soil type recommended by the OECD in ecotoxicity testing.

Evaluation of solid-phase microextraction conditions for the determination of chlorophenols in honey samples using gas chromatography.

A rapid and solvent-free method for the determination of nine chlorophenol (CP) compounds in honey samples using headspace solid-phase microextraction (HS-SPME) and gas chromatography with atomic emission detection (GC-AED) is developed. The different factors affecting the efficiency of the extraction and derivatization steps were carefully optimized. The polydimethylsiloxane-divinylbenzene (PDMS/DVB) fiber was the most suitable for preconcentrating the analytes from the headspace of an aqueous solution containing the dissolved honey samples where the chlorophenols had been submitted to acetylation. When the matrix effect was evaluated for different samples, it was concluded that standard addition calibration was required for quantification purposes. Detection limits roughly ranged from 0.1 to 2.4 ng g(-1), depending on the compound and the honey sample analyzed, with a fiber time exposure of only 15 min at 75 degrees C. The optimized method was successfully applied to different samples, some of the studied chlorophenols being detected in some of the analyzed honeys at concentration levels 0.6-9.4 ng g(-1).

Suppression of mouse complement activity by contaminants of technical grade pentachlorophenol.

Pentachlorophenol (PCP) is an antimicrobial agent used chiefly for the preservation of wood. Subchronic oral exposure (14 days) to Technical Grade PCP significantly inhibited the functional activity of female B6C3F1 mouse complement when measured in a microtiter hemolytic assay. When evaluated one day following the final exposure the highest administered dose (100 mg/kg) significantly suppressed the Classical complement pathway, the Spontaneous C1 autoactivation pathway, the Alternate pathway and the level of complement component, C3. Reconstitution studies using C5-deficient serum also demonstrated deleterious effects on this complement component. The Classical pathway was the most sensitive to Technical Grade PCP effects. Animals treated with 100 mg/kg Technical Grade PCP had CH 50 levels 30% of vehicle controls. Animals treated for 14 days and allowed a 15 day recovery period had CH 50 values 36% of control and animals which recovered for 30 days had only 52% of the complement activity of control animals. C3 recovery studies also demonstrated continued suppression on days 15 and 30 post-final exposure. Doses of 10 and 30 mg/kg did not produce the marked effects observed with the highest dose; however, a dose-dependent trend was observed for all responses. Animals treated with 100 mg/kg of EC-7, a PCP preparation with reduced amounts of contaminating dioxins and dibenzofurans, did not demonstrate detrimental effects on the complement system.