Genomic DNA Isolation by Phenol/Chloroform Extracting Method from Sheep Blood Clot

[ Objective] The aim was to establish the method of extracting genomic DNA from sheep blood clot on the basis of the improvement of method for extracting genomic DNA from tissues. [Method]The genomic DNA with complete primary structure and high purity was obtained from the sheep blood clot after the steps of cutting the sheep blood clot with ophthalmic scissors, cell lysis with tissue DNA extracts and digested by proteinase K, extracting with phenol/chloroform and precipitating with ethanol were performed. [ Result] The concentration of the extracted DNA was 159.90 ±0.70 ng/μl and the ratio of the A260/A280 was 1.80 ＋0.01. The sheep microsatellite locus of BM203 was amplified by using the extracted DNA from the sheep blood clot as template of PCR, and the PCR result was perfect. [Conclusion]This method is simple and feasible, the quantity and quality of the extracted DNA can satisfy the demands for the subsequent researches. It is worth to extending and using for reference.

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.

PVDMS-Al2O3 Composite Hollow Fibre Membranes for Chloroform Recovery from Gas Streams

Sorption isotherm of chloroform in polyvinyl dimethylsiloxane (PVDMS) polymer film was measured via the gravimetric method, and this film was confirmed experimentally to be good membrane material to recover chloroform from gas stream with high sorption capacity. A new PVDMS-Al2O3 composite hollow fibre membrane was further prepared by coating a PVDMS film on the outer surface of Al2O3 hollow fibre porpous substrate prepared by a dry/wet phase inversion method. Microstructure of the composite membranes was examined by scanning electron microscopy (SEM), indicating the PVDMS coating layer was uniform, free of defects, and around 15μm thick. Performance of the PVDMS-Al2O3 composite hollow fibre membranes for chloroform recovery was investigated. By comparing the experimental data that derived from a mathematical model, the permeabilities of chloroform and nitrogen in the PVDMS polymer membrane were obtained. The effects of temperature and feed flow rate on the chloroform recovery and permeate concentration were investigated both experimentally and theoretically.

DNA Extraction from Half-grain Wheat Seeds without Using Chloroform

In order to overcome the problems that DNA extraction from wheat leaves for PCR is restricted by seasons and chloroform is difficult to be acquired, a method of DNA extraction from wheat seeds without using chloroform was estab- lished in this study. The DNA extracted from wheat leaves and seeds using chloro- form was used as control, the quality of DNA extracted from wheat seeds without using chloroform was examined by muiti-PCR. The results showed that the concen- tration of DNA extracted from wheat seeds by chloroform-free method was lower than those extracted from wheat leaves and seeds using chloroform. The amplifica- tion effect of DNA extracted from wheat seeds by chloroform-free method was also a little worse than those extracted from wheat leaves and seeds using chloroform, but this problem can be addressed though loading higher quantity of DNA sample or adopting polyacrylamide gel electrophoresis method. Therefore, the chloroform-free DNA extraction method can be used when there are no special requirements for DNA quality or chloroform cannot be acquired timely.

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.

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.

氯甲酸十六酯生产工艺优化及其热稳定性实验

探讨了以光气、十六酯为原料制备氯甲酸十六烷基酯的最优工艺。考察了反应温度、反应溶剂、物料配比、光气用量对产品纯度的影响。结果显示。在20~30℃、m(十六醇)∶m(氯甲酸十六酯)=1∶1、通入1.2~1.4倍(物质的量比)光气的条件下,能够制备出纯度在99%以上、色度在50以下、w(十六醇)小于0.5%的氯甲酸十六酯优等品。基于优化后的生产工艺,探索了影响氯甲酸十六烷基酯色度的因素,并提出了降低色度的操作方法。通过对氯甲酸十六酯的热稳定性、金属离子热稳定性和热分解动力学的研究,进一步提升了生产过程中对安全风险的控制。对长烷烃链的氯甲酸酯类产品的安全工业化生产提供一定的技术支持及指导。

GB/T 5750.8—2023顶空-气相色谱法测定饮用水中三氯甲烷和四氯化碳的问题与建议

对GB/T 5750.8—2023中的顶空-气相色谱法测定生活饮用水中三氯甲烷和四氯化碳方法确认中影响定量准确性的因素,如分流比、色谱柱、基质空白、标准曲线配制等进行了讨论,并结合实验室的7697A顶空自动进样器、7890B气相色谱仪及所用DB-1701石英毛细管柱(30 m×0.25 mm×0.25μm)对方法进行了条件优化.采用优化后的试验条件对方法进行了确认.结果表明,三氯甲烷和四氯化碳分别在质量浓度为0.1~10.0μg/L和0.01~1.0μg/L范围内线性良好,检出限分别为0.025和0.0020μg/L,定量限分别为0.083和0.0067μg/L,相关系数r均大于0.999,相对标准偏差分别为4.2%~6.5%和1.8%~4.0%,加标回收率分别为96.8%~102.5%和104.0%~107.2%.优化后的方法可满足生活饮用水中三氯甲烷和四氯化碳的测定要求,为水中三氯甲烷和四氯化碳含量相关测试提供参考.

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.