ADSORPTION OF CHLOROFORM AND TRICHLOROETHYLENE IN WATER WITH A NEW KIND OF HYPERCROSSLINKED RESINS

In this paper two newly developed hypercrosslinked resins were used to treat micropolluted drinking water and their static and kinetic adsorption were investigated at 293 K. The results show that these two adsorbents are superior to Amberlite XAD-4 for removing chloroform and trichloroethylene in aqueous solutions. The breakthrough capacity and the total capacities from mini-column adsorption studies for chloroform and trichloroethylene on XAD-4, ZH-01 and ZH-00 are calculated respectively under experimental conditions

Electrochemical dechlorination of chloroform in neutral aqueous solution on palladium/foam-nickel and palladium/polymeric pyrrole film/foam-nickel electrodes

Electrochemical dechlorination of chloroform in neutral aqueous solution was investigated using palladium-loaded electrodes at ambient temperature. Palladium/foam-nickel （Pd/foam-Ni） and palladium/polymeric pyrrole film/foam-nickel （Pd/PPy/foam-Ni） composite electrodes which provided catalytic surface for reductive dechlorination of chloroform in aqueous solution were prepared using an electrodepositing method. Scanning electron microscope （SEM） micrographs showed that polymeric pyrrole film modified the electrode-surface characteristics and resulted in the uniform dispersion of needle-shaped palladium particles on foam-Ni supporting electrode. The experimental results of dechlorination indicated that the removal efficiency of chloroform and current efficiency in neutral aqueous solution on Pd/PPy/foam-Ni electrode could be up to 36.8% and 33.0% at dechlorination current of 0.1 mA and dechlorination time of 180 min, which is much higher than that of Pd/foam-Ni electrode.

Chloroform Aided Extraction Spectrophotometric Determination of Rhenium Using Thiocyanate Complexing Agent

A new technique is developed for quantitative determination of rhenium in aqueous media containing molybdenum, iron and copper ions. The method seems easier and more accurate than the traditional ones. It consists of the formation of rhenium thiocyanate complex, which is extracted with chloroform at the presence of hydrochloric acid. This complex is a highly visible light absorbent that can easily be detected with the aid of a spectrophotometer. The maximum absorbance (λmax) observed for this complex was in the visible range of 430-435 nm. The experimental results showed that in a concentration range from 0.5-8 mg/L, the absorbance behavior of the rhenium thiocyanate complex is followed to the Beer-Lambert law.

An incident of chloroform poisoning on a university campus

Dear editor,University laboratory-related events include fire,explosion,chemical gas leakage,poisoning related to the loss of toxic reagents,specific pathogen infection,leakage of radioactive material,etc.[1]Chloroform is an important material used frequently in the laboratory,for organic synthesis or used as an organic glass binder and organic matter extractor.[2]As a widely used anesthetic in clinics in the 1950s and the 1960s,[3]chloroform was abandoned because of hepatorenal toxicity.We report a case of a 24-year-old suicidal female student with chloroform poisoning.

Encapsulation of a Chloroform Molecule in a Peptide Nanotube

We determine the encapsulation of a chloroform molecule into a D,L-Ala cyclopeptide nanotube by investigating the interaction energy between the two molecular structures. We employ the Lennard-Jones potential and a continuum approach which assumes that the atoms are evenly distributed over the molecules providing average atomic densities. Our result demonstrates that the encapsulation depends on the size of the molecule and the internal diameter of the peptide nantube. In particular, the on-axis chloroform molecule is only accepted into a peptide nanotube whose internal radius is greater than 5 ?. If located near the edge of the nanotube, then it is unlikely that the chloroform molecule will enter the nanotube. This is due to the energy valley that the molecule will need to overcome to move past the edge into the open end of the nanotube.

Studies on Photocatalytic Degradation of Acridine Orange and Chloroform Sensing Using As-Grown Antimony oxide Microstructures

Flower shaped antimony oxide (Sb2O3) microstructures were synthesized in a large quantity via simple solution method using aqueous mixtures of antimony chloride and hexamethylene diamine (HMDA). The morphological characterizations were done by field emission scanning electron microscopy (FESEM), which revealed that the synthesized products possess flower-shaped microstructures. The detailed structural characterizations performed by X-ray diffraction (XRD), Fourier transform infrared spectrophotometer (FT-IR) and Raman spectrophotometer confirmed that the synthesized microstructures are well-crystalline antimony oxide. The Energy dispersive spectroscopy (EDS) shows that the grown products are composed of Sb and O. Optical properties of the synthesized products were characterized by UV-Visible spectrophotometer which exhibits a well defined peak at ~ 291.0 nm. The photo-catalytic activity of the Sb2O3 microstructures was evaluated by degradation of acridine orange (AO), which mineralized almost 63.0% in 150 min. The chemical sensing properties of Sb2O3 microstructures was also studied by I-V technique using chloroform as a detecting solvent. The fabricated chloroform sensor demonstrates good sensitivity of 0.1154 μA cm–2 mM–1, lower-detection limit (~0.1 mM), large-linear dynamic range (LDR, 0.122 mM to 1.22 M) with linearity (R = 0.7898) in short response time (10.0 sec).

Determination of Enantiomeric Composition of Substituted Tetrahydroisoquinolines Based on Derivatization with Menthyl Chloroformate

A method for the analysis of the optical purity of a series of chiral substituted tetrahydroisoquinolines (THIQs) was developed. The method is based on pre-column derivatization of the analytes with the derivatization reagent (–)-(1R)-menthyl chloroformate. The derivatization reaction selectively gives diastereomeric carbamates that are resolvable on an achiral non-polar GC column. The developed technique covers variously substituted THIQs, which differ significantly in volatility, steric and electronic properties. In all cases, the resolution factors (R) exceeded the value of 1.5. The method represents a robust way of analysis of mixtures of THIQs, which are often present in various matrixes such as body fluids, tissues and reaction mixtures.

Increase in Organochlorine Contaminant Levels in Major Water Sources of the United States in Response to the Coronavirus Pandemic

Organochlorine contaminants, such as triclosan (TCS), are present in major water sources across the United States. These antimicrobial compounds are widely used as multipurpose ingredients in everyday consumer products. They can be ingested or absorbed through the skin and are found in human blood, breast milk, and urine samples. Studies have shown that the increased use of antimicrobial agents leads to their presence and persistence in the ecosystem, particularly in soil and watersheds. Many studies have highlighted emerging concerns associated with the overuse of TCS, including dermal irritations, a higher incidence of antibacterial-related allergies, microbial resistance, disruptions in the endocrine system, altered thyroid hormone activity, metabolism, and tumor metastasis and growth. Organochlorine contaminant exposures play a role in inflammatory responsiveness, and any unwarranted innate response could lead to adverse outcomes. The capacity of TCS and other organochlorine contaminants to induce inflammation, resulting in persistent and chronic inflammation, is linked to various pathologies, such as cardiovascular disease and several types of cancers. Chronic inflammation presents a severe consequence of exposure to these antimicrobial agents, as any changes could result in the loss of immune competence. Organochlorine contaminant levels were established by the United States Environmental Protection Agency (EPA) in 2019-2020 and have consistently increased in response to the novel coronavirus (nCoV) (COVID-19) pandemic. Our previous research examined the overuse of products containing triclosan (TCS), which led to an increase in total trihalomethane (TTHM) levels affecting the quality of our water supply. We also investigated the impact of the FDA ban that now requires pre-market approval. To comprehend the consequences of excessive antimicrobial use on water quality, we conducted an analysis of the levels of total trichloromethane (chloroform), a byproduct of free chlorine added to TCS, in primary water sources in metropolitan areas across the United States in 2019-2020. We repeated this analysis after the peak of the COVID-19 pandemic in 2021-2022 to examine its correlation with organochlorine exposure. Our study found that the COVID-19 pandemic, along with the increased use of antimicrobial products, has significantly raised the levels of total trihalomethanes compared to those reported in water quality reports from 2019-2020, in contrast to the reports from 2021-2022.

Characterization of Methylocystis strain JTA1 isolated from aged refuse and its tolerance to chloroform

To accelerate the efficiency of methane biodegradation in landfills, a Gram-negative, rod-shaped, non-motile, non-spore-forming bacterium, JTA1, which can utilize methane as well as acetate, was isolated from the Laogang MSW landfills, Shanghai, China. Strain JTA1 was a member of genus Methylocystis on the basis of 16S rRNA and pmoA gene sequence similarity. The maximum specific cell growth rates （μmax= 0.042 hr-1, R2= 0.995） was derived through Boltzmann simulation, and the apparent half-saturation constants （Km（app） = 7.08 mmol/L, R2 = 0.982） was calculated according to Michaelis-Menton hyperbolic model, indicating that Methylocystis strain JTA1 had higher-affinity potential for methane oxidation than other reported methanotrophs. By way of adding the strain JTA1 culture, the methane consumption of aged refuse reached 115 mL, almost two times of control experiment. In addition, high tolerance of Methylocystis strain JTA1 to chloroform could facilitate the methane oxidation of aged refuse bio-covers. At the chloroform concentration of 50 mg/L, the methane-oxidation rate of bio-cover reached 0.114 mL/（day.g）, much higher than the highest rate, 0.0135 mL/（day.g）, of reported bio-covers. In conclusion, strain JTA1 opens up a new possibility for environmental biotechnology, such as soil or landfills bioremediation and wastewater decontamination.

Fenton process for degradation of selected chlorinated aliphatic hydrocarbons exemplified by trichloroethylene,1,1-dichloroethylene and chloroform

The degradation of selected chlorinated aliphatic hydrocarbons(CAHs)exemplified by trichloroethylene(TCE),1,1-dichloroethylene(DCE),and chloroform(CF)was investigated with Fenton oxidation process.The results indicate that the degradation rate was primarily affected by the chemical structures of organic contaminants.Hydroxyl radicals(·OH)preferred to attack the organic contaminants with an electron-rich structure such as chlorinated alkenes(i.e.,TCE and DCE).The dosing mode of Fenton’s reagent,particularly of Fe^(2+),significantly affected the degradation efficiency of studied organic compound.A new“time-squared”kinetic model,C=C_(oexp)(-k_(obst)^(2)),was developed to express the degradation kinetics of selected CAHs.This model was applicable to TCE and DCE,but inapplicable to CF due to their varied reaction rate constants towards·OH.Chloride release was monitored to examine the degree of dechlorination during the oxidation of selected CAHs.TCE was more easily dechlorinated than DCE and CF.Dichloroacetic acid(DCAA)was identified as the major reaction intermediate in the oxidation of TCE,which could be completely removed as the reaction proceeded.No reaction intermediates or byproducts were identified in the oxidation of DCE and CF.Based on the identified intermediate,the reaction mechanism of TCE with Fenton’s reagent was proposed.

雾水葛提取物抑制脂多糖诱导的人泪腺上皮细胞炎症反应的实验研究

目的 观察雾水葛提取物对人泪腺上皮细胞活力和炎症的影响,鉴定活性单体并探索药理机制。方法 选取宁波市眼科医院收治的一位25岁女性泪腺炎患者,分离培养其人泪腺上皮细胞,免疫荧光法检测细胞标志物表达以鉴定细胞,不同剂量脂多糖(LPS)诱导细胞炎症反应,四甲基偶氮唑盐比色(MTT)检测细胞活力筛选LPS最佳剂量。使用水、氯仿、乙酸乙酯、正丁醇分别提取雾水葛活性成分,MTT法检测不同溶剂和剂量雾水葛提取物对人泪腺上皮细胞活力的影响。通过电喷雾质谱和核磁共振谱图确定氯仿提取物中活性成分的结构,将鉴定得到的5种化合物(LF1~5)进行药物靶标的预测,Western Blot法检测5种化合物的雾水葛提取物对人泪腺上皮细胞炎症相关蛋白表达的影响。结果 (1)细胞鉴定:角蛋白(CK)14、CK7、E-钙黏蛋白(E-cadherin)等阳性表达确定得到的是人泪腺上皮细胞和少量肌上皮细胞。(2)剂量筛选:处理48 h和72 h后,当LPS浓度为80 mg/L时,细胞活力开始低于对照组,差异有统计学意义(t_(48 h)=6.827、t_(72 h)=6.222,均P=0.002),故LPS浓度80 mg/L、处理时间为24 h为最佳诱导方法。高浓度下,不同雾水葛提取物都具有对细胞活力的抑制作用,2.5、5、10、20μg/mL为提取物的适宜浓度。(3)雾水葛氯仿提取物中物质鉴定:LF-1为(-)-Epicatechin,LF-2为8-(2-Pyrrolidinone-5-yl)-(-)-epicatechin,LF-4为3’-Demethylicariside E3,LF-3、LF-5为首次发现。(4)药物靶标筛选:5种氯仿提取物中,一共有5个共同靶点,分别为花生四烯酸5-氧化酶活化蛋白(ALOX5)、白细胞介素(IL)-2、IL-6、核因子κB1(NF-κB1)和血管内皮生长因子A(VEGFA)。(5)炎症相关蛋白:5种雾水葛的氯仿提取物都能不同程度地抑制炎症相关蛋白的水平,其中以LF-3的抑制效果最佳。结论 雾水葛提取物能够抑制LPS诱导的人泪腺上皮细胞的炎症反应,其中以氯仿提取物中的LF-3成分的药理活性最佳。

基于荧光光谱法的Cryptophane-E-Me@氯仿络合作用研究

报道了含甲基取代的cryptophanes合成方法,并用荧光光谱法研究了其对氯仿的识别性能。其中cryptophane-E-Me与氯仿有更强的络合作用,其络合常数为480.5 L·mol^(-1)。这种cryptophane-E-Me与氯仿间较强及稳定的络合作用提供了一种方便、环保的痕量氯仿检测方法。

含氯仿废水处理技术研究进展

对含氯仿废水的处理方法、原理以及研究现状进行综述。处理方法可分为生物法、物理化学法、化学法和其他方法,分析几种方法的优缺点。通过对目前氯仿废水处理技术的分析,提出未来的发展前景和建议。

A New Initiator Cholesteryl Chloroformate for Cupper-Based Atom Transfer Radical Polymerization of Methyl Methacrylate

The polymerization of metyl methacrylate (MMA) was studied in detail by use of CuCl/L as a catalyst and cho-lesteryl chloroformate (CC) as an initiator. It was found that the atom transfer radical polymerization of MMA could proceed when L equals to a multidentate aliphatic amine ligand, N,N,N',N'',N″-penta(methyl acry-late)diethylenetriamine (MA5-DETA), and no polymerization was occurred while L=2,2'-bipyridine and 1,10- phenanthroline. The linear proportionality of the molecular weights to the conversions and straight lines observed in ln[M]0/[M] versus time plots indicated that the present polymerization system had the typical controlled polymeri-zation characteristics.

Evidence of Hydrogen Bonding in Chloroform and Polyacrylates from NMR Measurements

The presence of hydrogen bonding in chloroform and polyacrylate mixtures was demonstrated by observation of 1H and 13 C NMR chemical shifts. Comparison of the nuclear magnetic resonance (NMR) chemical shift in polymer solutions with their low molecular mass analogues showed the effect of steric hindrance on hydrogen bonding. This initial investigation is helpful for understanding the intermolecular interaction in relatively weak hydrogen bonding polymer solutions.

Bioelectrochemically-assisted degradation of chloroform by a coculture of Dehalobacter and Dehalobacterium

Using bioelectrochemical systems(BESs)to provide electrochemically generated hydrogen is a promising technology to provide electron donors for reductive dechlorination by organohalide-respiring bacteria.In this study,we inoculated two syntrophic dechlorinating cultures containing Dehalobacter and Dehalobacterium to sequentially transform chloroform(CF)to acetate in a BES using a graphite fiber brush as the electrode.In this co-culture,Dehalobacter transformed CF to stoichiometric amounts of dichloromethane(DCM)via organohalide respiration,whereas the Dehalobacterium-containing culture converted DCM to acetate via fermentation.BES were initially inoculated with Dehalobacter,and sequential cathodic potentials of-0.6,-0.7,and -0.8 V were poised after consuming three CF doses(500 μM)per each potential during a time-span of 83 days.At the end of this period,the accumulated DCM was degraded in the following seven days after the inoculation of Dehalobacterium.At this point,four consecutive amendments of CF at increasing concentrations of 200,400,600,and 800 μM were sequentially transformed by the combined degradation activity of Dehalobacter and Dehalobacterium.The Dehalobacter 16S rRNA gene copies increased four orders of magnitude during the whole period.The coulombic efficiencies associated with the degradation of CF reached values>60% at a cathodic potential of -0.8 V when the degradation rate of CF achieved the highest values.This study shows the advantages of combining syntrophic bacteria to fully detoxify chlorinated compounds in BESs and further expands the use of this technology for treating water bodies impacted with pollutants.

A validated HPLC method for the determination of donepezil in human plasma after derivatization with 9-fluorenylmethyl chloroformate

A new HPLC method has been developed for determining donepezil in human plasma. To find the optimum conditions, a derivatization reaction was performed in different media, and the reaction product was identified by NMR and GC-MS after a semi-preparative HPLC separation. Under optimized conditions, donepezil was derivatized by 9-fluorenylmethyl chloroformate in chloroform and carbonate buffer at pH 9.5 in the presence of NaI after solid-phase extraction from a plasma sample. The reaction product was quantified on a reversed-phase TRACER EXCEL ODS-A, 5 μm column using a mixture of acetonitrile–10 mM acetate buffer(pH 6.0)–THF(60:35:5, v/v/v) as the mobile phase with fluorescence detection at 264 nm(ex) and 313 nm(em). Fluoxetine was used as the internal standard. The total run-time of the analysis was about 10 min, and a clean chromatogram was obtained. The developed method was linear over the range of 1–100 ng/mL in 500 μL of plasma samples(r2>0.998). The intra-day and inter-day precision values were in the range of 2.6%–11.6%. The limit of quantification was 1 ng/mL.

Final Ruling on Imported Chloroform

Chin continues to impose antidumping tariff on imported chloroform (HS code:29031300) originated from the European Union,the United States and Korea for four years,effective November 30th,2010.The nation had taken antidumping measures on imported chloroform from the European Union,the United States,Korea and India for five years since November 30th,2004. (CCR2004 No. 11)

氯仿萃取分离N,N-二甲基甲酰胺工艺

针对某制药企业生产过程中产生的高浓度含N,N-二甲基甲酰胺(DMF)料液,在折流板萃取塔内进行连续萃取分离,结合精馏工艺,实现了DMF的分离与回收。对于DMF初始质量分数为38.46%的料液,以氯仿作为萃取剂,采用脉冲折流板萃取塔对料液中的DMF进行萃取,研究了不同油水相比、流量和脉冲条件下在折流板萃取塔中DMF的萃取效果。结果表明,DMF的萃取效率随着脉冲的加入、油水相比的升高和两相流速的增大而增大,在优化的条件下DMF的萃取率最高为99.94%,分离后的萃余相DMF质量分数达到0.5%以下。进一步,对于负载了DMF的氯仿溶液,分别进行了间歇精馏实验和模拟计算,结果显示通过精馏可以实现氯仿和DMF的有效分离回收。

基于NHANES数据库的血液氯仿与糖尿病及相关糖脂代谢指标的关联性研究

目的:探讨人群血液中氯仿浓度与糖尿病患病风险的相关性,为糖尿病的预防和控制提供依据。方法:使用2017至2018年美国国家健康和营养调查(National Health and Nutrition Examination Survey,NHANES)数据。排除妊娠期妇女和年龄<18周岁的青少年,以及氯仿浓度缺失和未完成糖尿病调查的参与者,共622人纳入本次分析。将所有参与者根据血液中氯仿浓度按照三分位法分为T1组(氯仿<0.011μg/L),T2组(0.011μg/L≤氯仿<0.017μg/L)和T3组(氯仿≥0.017μg/L),使用Logistic回归分析3组间糖尿病患病率的差异,并利用立方样条图展示氯仿与糖尿病患病风险之间的相关性。结果:糖尿病发生风险随氯仿浓度的增高而增加(T3组比T1组增加约1.23倍);使用限制性立方样条分析结果显示,氯仿与空腹血糖、稳态模型评估胰岛素抵抗指数(homeostatic model assessment of insulin resistance,HOMA-IR)和糖尿病发生风险呈正相关且具有统计学意义;进一步使用偏相关分析也同样发现氯仿与空腹血糖和HOMA-IR之间存在正相关;此外,亚组分析结果也显示氯仿是糖尿病的风险因素。结论:氯仿暴露是糖尿病的独立危险因素,可以增加胰岛素抵抗,从而加重糖尿病的患病风险。