对羧基苯偶氮硫代若丹宁固相萃取光度法测定环境样品中的铅

合成了新试剂对羧基苯偶氮硫代若丹宁(CPATR),并用红外光谱、核磁共振氢谱和元素分析鉴定其结构。研究了CPATR与铅的显色反应,在pH3 8的HAc—NaAc缓冲介质中,吐温-80存在下,CPATR与铅反应生成2∶1稳定络合物,该络合物可被WatersSep-PakC18小柱固相萃取,小柱上富集的络合物用乙醇洗脱后富集倍数可达50倍,在乙醇介质中,λmax=500nm,体系摩尔吸光系数ε=8.01×104L·mol-1·cm-1。铅含量在0 05～4 0mg/L内符合比耳定律。本方法可用于环境样品中铅含量的测定,结果满意。     

经济转型中的中国废钢铁投资市场

废钢铁产业是我国再生资源产业的主体,其节能减排、低碳环保和不可替代的钢铁原料功效十分显著。阐述了我国废钢铁产业在经济转型中的主导地位、应用价值、投资环境及今后的发展战略。指出我国经济发展方式的转变,赋予了废钢铁产业良好的发展机遇和重大的历史使命,中国废钢产业具有良好的投资市场和巨大的发展空间。     

Early murine immune responses from endotracheal exposures to biotechnology-related Bacillus strains

An immunology-based in vivo screening regime was used to assess the potential pathogenicity of biotechnology-related microbes. Strains of Bacillus cereus (Bc), Bacillus subtilis (Bs), Bacillus thuringiensis (Bt), and Bt commercial products (CPs) were tested. Balb/c mice were endotracheally instilled with purified spores, diluted CP, or vegetative cells (VC) (live or dead). Exposed mice were evaluated for changes in behavioral and physical symptoms, bacterial clearance, pulmonary granulocytes, and pulmonary and circulatory pyrogenic cytokines (interleukins (IL)-1β, IL-6 and tumor necrosis factor (TNF)-α), as well as acute phase biomarkers (fibrinogen and serum amyloid A). Except for some differences in clearance rates, no marked effects were observed in mice exposed to any spore at 10⁶ or 10⁷ colony forming units (cfu). In contrast, live Bc or Bt VCs (10⁵ or 10⁶?cfu) produced shock-like symptoms (lethargy, hunched appearance, ruffled fur, and respiratory distress), and 11–200-fold elevations in pyrogenic cytokines at 2-h post-exposure. In the study, 4-h effects included increased lethargy, ocular discharge, and 1.5–4-fold rise in circulatory acute phase markers, but no indications of recovery. Bs VC did not produce any changes in symptoms or biomarkers. After 2 or 4?h of exposure to dead VC, increases of only plasma IL-1β and TNF-α (4.6- and 12.4-fold, respectively) were observed. These findings demonstrate that purified spores produced no marked effects in mice compared to that of metabolically active bacteria. This early screening regime was successful in distinguishing the pathogenicity of the different Bacillus species, and might be useful for assessing the relative hazard potential of other biotechnology-related candidate strains.     

Oxidized multiwalled carbon nanotubes modified with 2-(2-hydroxy-5-nitrophenyl)-4,5-diphenyl imidazole for solid phase extraction and preconcentration of some metal ions

In this work, a new procedure for the enrichment of the trace amount of Cu²⁺, Ni²⁺, Co²⁺, Pb²⁺, Fe²⁺, and Zn²⁺ ions based on the utilization of multiwalled carbon nanotubes (MWCNT) modified with 2-(2-hydroxy-5-nitrophenyl)-4,5-diphenyl imidazole as chelating agent prior to their determination by flame atomic absorption spectrometry has been described. The influence of effective parameters including pH, amount of ligand and MWCNT, composition of eluent, and coexisting ions on recoveries of understudy metal ions was examined. At the optimum pH of 5.0, all metal ions were quantitatively sorbed onto the proposed solid phase and completely desorbed with 8?mL of 5.0?mol?L^?1 HNO₃. The detection limit of Cu²⁺, Co²⁺, Ni²⁺, Pb²⁺, Fe²⁺, and Zn²⁺ ions was 1.7, 2.4, 2.3, 2.9, 2.8, and 1.4?µg?L^?1, while the preconcentration factor was 63 for Cu²⁺ and 94 for the other metal ions and relative standard deviations between 1.8 less than 3.0%. The proposed procedure was applied for the analysis of various samples.     

Determination of cadmium in water and herbal medicine by Penicillium chrysogenum immobilized on silica gel for flame atomic absorption spectroscopy

Penicillium chrysogenum was immobilized on silica to develop a simple and cost effective method for solid phase extraction of Cd(II) and determination using flame atomic absorption spectrometry (FAAS). The sorbent was characterized by Fourier transform infrared spectroscopy and packed into a column. The conditions for quantitative sorption and desorption of Cd(II) were optimized. The preconcentration factor was 100 while detection limit was 0.61 µg L^?1 with a relative standard deviation of 1.0%. The method was applied for determination of Cd in herbal medicine and tap water.     

Comments on the Carcinogenicity and Mutagenicity of metals and their compounds†

The carcinogenicity of metals has received extensive study, both epidemiologically and in the laboratory. These have included case reports of occasional human occurrence or clusters of cancer cases as well as extensive epidemiologic studies; in addition, there has been significant laboratory research on the whole animals and in vitro systems. This body of information will be examined selectively.

I will not in this paper attempt a comprehensive review of the mutagenicity and carcinogenicity of metals and their compounds. Rather, I will attempt to set forth some historical perspectives, and to comment on some current gaps and needs.

Other papers in this workshop have presented thorough and very current reviews of most of the topics briefly noted in this presentation and do not require repetition here.

The cancer issue has been studied and reported on far more extensively than that relating to heritable mutations. There has been in recent years increasing interest in the use of short term tests for mutagenicity and cell transformation. These, however, are primarily with respect to their relationship to cancer production rather than to germ cell injury. Interest in cancer from metal compounds goes back a long time; in fact, one of the earliest reports was on the carcinogenicity of arsenic not many decades after the pioneering report of Sir Perceval Pott on cancer in chimney sweeps. Since then cancer has been definitely associated in humans with chromium compounds, nickel, and with less assurance but probably definitely with beryllium and cadmium. The confirmation of these findings in laboratory animals has been uneven. In the case of arsenic, for example, there has been only limited success in the production of cancer in laboratory animals with arsenic.

Many other metals have been found in laboratory studies to produce cancer, although with most of these, evidence of production of cancer in humans is either absent or extremely uncertain.

The extensive body of recent information relating to the testing of metals with a variety of short term tests will be briefly reviewed.     

Occupational exposures,delivered doses and exposure limits for chromium and nickel†

The interaction of HCH (50 mg/kg) and dietary protein levels on microsomal drug metabolizing enzymes system and liver lipids were studied in the rats for 90 days. The results indicated that rats fed a lower protein diet and HCH has a higher rate of mortality, lower rate of growth and an increased liver weight. A significant induction in the hepatic microsomal aminopyrine‐N‐demethylase, p‐nitroanisole‐O‐dealkylase, benzo(a)pyrene hydroxylase and glutathione‐S‐transferase activity was observed in pesticide treated animals as compared to control animals. The pathological changes observed in liver of HCH treated animals consisted mainly of necrosis and fatty degeneration of hepatocytes. HCH also induced the significant accumulation of cholesterol, triglycerides, phospholipid and total lipid in liver in low protein diet animals. Protein accelerates the metabolism of HCH, resulting in a decrease of HCH concentration with the increase of dietary protein level. A close correlation existed between lipid accumulation, induction of drug metabolizing enzyme system and deposition of HCH in liver.     

Pah characteristics in ambient air within a steel industrial complex

Ambient air samples at ten sites in an iron and steel industrial complex were collected from June to December for analyzing polycyclic aromatic hydrocarbons (PAHs). Sixteen species of PAH components in air samples were identified. The results indicate that both gaseous phase and particle‐bound PAHs at the top of the cokemaking plants are unusually high. The profiles of particle‐bound PAHs indicate that the predominant species at the top of, the coke oven batteries are those of high molecular weight components. The major components of particle‐bound PAHs at sampling sites near the fenceline, however, include the medium molecular weight components. The PAH profiles of air samples within the industrial complex show a strong similarity to those of cokemaking plant samples. The concentrations and the specific content of benzo(a)pyrene in the iron and steel industrial complex are higher than those values measured in urban area, petrochemical industry park, and open‐air burning area.     

Cleanup by solid‐phase extraction and HPLC of organochlorine insecticides and PCBS in various nonfatty and fatty samples

An accurate, simple and cheap extraction and cleanup procedure for capillary GC analysis of organo‐chlorine insecticides (OCs) in vegetables (cabbage and carrots) at the ng/g level, and for soil at the μg/g level is presented. The cleanup is carried out on solid‐phase extraction (SPE) cartridges, filled with 500 mg silica, 1 g of deactivated Florisil (10% w/w water), and 100 mg of anhydrous sodium sulphate. Recoveries >90% are obtained. The cleanup of OCs in fatty samples on an HPLC LiChrosorb Si 100 column is evaluated for subsequent capillary GC analysis. Fractionation of OCs and Aroclor 1254 and 1260 on an HPLC Nucleosil 100 column appears to be satisfactory.     

Evaluation of linear alkylbenzenesulfonate (LAS) biodegradability in sediment by solid‐phase extraction and HPLC analysis

The linear alkylbenzenesulfonate (LAS) sorption on environmental sediments has been known long ago. Their high concentrations reflect the massive input of these chemicals from household and industrial uses. However few attempts were made to identify biodegradation metabolites of LAS in sediment. In this report, a method for the determination of these compounds in sediment samples by high‐performance liquid chromatography (HPLC) is described. The first step of our work was performed by solid‐phase extraction with octadecyl‐bonded silica (C18) mini‐columns and provided a suitable recovery of LAS (90 ± 5%) and most metabolites. Furthermore, laboratory investigations led to study the behaviour of LAS in sediment. The environmental samples used for this purpose were collected from a pond (named étang de Bolmon) located in the French Mediterranean coast. Our results were in agreement with an aerobic biodegradation process of LAS that occurred only with high values of sediment redox potential and needed the samples to be vigorously shaken to ensure adequate mixing and suspension of particulate material. In a stagnant sediment or under anaerobic conditions, LAS is not degraded. p‐Sulfophenylacetic acid and p‐sulfocinnamic acid were evidenced as predominant metabolites and were found not to be persistent.