Extraction and isolation of linear alkylbenzenesulfonate and its sulfophenylcarboxylic acid metabolites from fish samples

Linear alkylbenzenesulfonate (LAS) is the most widely used synthetic surfactant. In fish, assessment of the environmental risk and investigation of the biotransformation behavior of LAS require compound-specific methods for extraction and isolation of LAS and its biotransformation products, sulfophenylcarboxylic acids (SPC). Matrix solid-phase dispersion (MSPD) extraction with subsequent ion-pair liquid-liquid (IP-LL) partitioning of the extract was a time-efficient sample preparation method for analysis of LAS. The recovery of parent LAS from spiked fish exceeded 70%, and the limit of quantitation ranged around 0.2 mg.kg-1 corresponding to 0.6 mumol.kg-1. In a simultaneous determination of LAS and SPC in fish, the analytes were MSPD extracted in different fractions. The target compounds were separated from the sample matrix by protein precipitation and subsequent isolation of (a) SPC by graphitized carbon black solid-phase extraction of the supernatant and (b) parent LAS by IP-LL partitioning of the pellet obtained after protein precipitation. The recoveries of the model compounds C12-2-LAS and C4-3-SPC were 84 +/- 6 and 65 +/- 11%, respectively. The use of C3-3-SPC as an internal standard corrected for the loss of the biotransformation product during sample workup. The suitability of both methods was demonstrated by analyzing fish containing LAS and SPC incurred during aqueous exposure.     

Semiautomated device for batch extraction of metabolites from tissue samples

Metabolomics has become a mainstream analytical strategy for investigating metabolism. The quality of data derived from these studies is proportional to the consistency of the sample preparation. Although considerable research has been devoted to finding optimal extraction protocols, most of the established methods require extensive sample handling. Manual sample preparation can be highly effective in the hands of skilled technicians, but an automated tool for purifying metabolites from complex biological tissues would be of obvious utility to the field. Here, we introduce the semiautomated metabolite batch extraction device (SAMBED), a new tool designed to simplify metabolomics sample preparation. We discuss SAMBED's design and show that SAMBED-based extractions are of comparable quality to extracts produced through traditional methods (13% mean coefficient of variation from SAMBED versus 16% from manual extractions). Moreover, we show that aqueous SAMBED-based methods can be completed in less than a quarter of the time required for manual extractions.     

Molecularly imprinted solid-phase extraction of diazepam and its metabolites from hair samples

An anti-diazepam, molecularly imprinted polymer (MIP) has been synthesized and used to extract diazepam and other benzodiazepines from hair samples via a molecularly imprinted solid-phase extraction (MISPE) protocol. Optimum retention of diazepam on the MIP columns was achieved using an apolar solvent, and the binding capacity of the polymer toward diazepam was found to be 110 ng of diazepam/mg of polymer. The recovery of a 50 ng diazepam standard spiked into blank hair was 93%, with good precision (RSD = 1.5%). The LOD and LOQ of diazepam in spiked hair samples were 0.09 and 0.14 ng/mg, respectively. The MISPE method was demonstrated to be applicable to the analysis of diazepam metabolites and other benzodiazepine drugs, in addition to diazepam itself. The application of the extraction method to postmortem hair samples yielded results that were in good agreement with the corresponding ELISA data (from blood samples) and data arising from the analysis of the same blood samples using a validated in-house SPE-LC-MS-MS method.     

MALDI-FTICR imaging mass spectrometry of drugs and metabolites in tissue

A new approach is described for imaging mass spectrometry analysis of drugs and metabolites in tissue using matrix-assisted laser desorption ionization-Fourier transform ion cyclotron resonance (MALDI-FTICR). The technique utilizes the high resolving power to produce images from thousands of ions measured during a single mass spectrometry (MS)-mode experiment. Accurate mass measurement provides molecular specificity for the ion images on the basis of elemental composition. Final structural confirmation of the targeted compound is made from accurate mass fragment ions generated in an external quadrupole-collision cell. The ability to image many small molecules in a single measurement with high specificity is a significant improvement over existing MS/MS based technologies. Example images are shown for olanzapine in kidney and liver and imatinib in glioma.     

Shotgun metabolomics approach for the analysis of negatively charged water-soluble cellular metabolites from mouse heart tissue

A shotgun metabolomics approach using MALDI-TOF/TOF mass spectrometry was developed for the rapid analysis of negatively charged water-soluble cellular metabolites. Through the use of neutral organic solvents to inactivate endogenous enzyme activities (i.e., methanol/chloroform/H2O extraction), in conjunction with a matrix having minimal background noise (9-amnioacridine), a set of multiplexed conditions was developed that allowed identification of 285 peaks corresponding to negatively charged metabolites from mouse heart extracts. Identification of metabolite peaks was based on mass accuracy and was confirmed by tandem mass spectrometry for 90 of the identified metabolite peaks. Through multiplexing ionization conditions, new suites of metabolites could be ionized and "spectrometric isolation" of closely neighboring peaks for subsequent tandem mass spectrometric interrogation could be achieved. Moreover, assignments of ions from isomeric metabolites and quantitation of their relative abundance was achieved in many cases through tandem mass spectrometry by identification of diagnostic fragmentation ions (e.g., discrimination of ATP from dGTP). The high sensitivity of this approach facilitated the detection of extremely low abundance metabolites including important signaling metabolites such as IP3, cAMP, and cGMP. Collectively, these results identify a multiplexed MALDI-TOF/TOF MS approach for analysis of negatively charged metabolites in mammalian tissues.     

一株石韦内生真菌S-34的鉴定及其代谢物检测与分析

以药用植物有柄石韦叶为材料,采用组织块法与微量稀释法分离并筛选出一株具有抑菌活性的内生真菌S-34。经形态学观察、ITS测序与序列比对鉴定内生真菌S-34为链格孢属(Alternaria sp.)。进一步利用GC-MS对其代谢物进行检测与分析,结果显示:内生真菌S-34发酵液乙酸乙酯提取物的抑菌成分主要为氟苯甲酸(20.86%)、苯乙醇(4.89%)、2,3-丁二醇(3.64%),菌体乙酸乙酯提取物的抑菌成分主要为苯甲醛(2.27%)、亚麻醇(2.53%)、亚油酸单甘油酯(1.69%)、亚麻酰氯(9.28%)、反式角鲨烯(7.26%)、麦角甾醇(2.78%)。研究表明,有柄石韦内生真菌S-34的代谢物中蕴藏着较为丰富的抑菌活性物质,是开发天然药物的潜在资源。     

Extraction behaviour of 2-octylaminopyridine towards lead(II) from succinate media and its separation from other toxic metals

Liquid-liquid extraction of lead(II) from succinate media was carried out with 2-octylaminopyridine (2-OAP) in chloroform. Lead(II) was quantitatively extracted with 0.036 M 2-OAP in chloroform from 0.005-0.007 M sodium succinate when equilibrated for 5 min. Lead(II) from the organic phase was stripped with three 10 mL portions of 0.4M acetic acid and determined titrimetrically with EDTA. The nature of extracted species was determined from the log-log plot. The optimum conditions have been evaluated based on a critical study of weak acid concentration, extractant concentration, period of equilibration and effect of diluents. The metal loading capacity of the reagent was found to be 8 mg of lead(II) with 10 mL 0.036 M of the extractant. The extraction of the lead(II) was carried out in presence of various ions to ascertain the tolerance limit of individual. Temperature dependence of the extraction equilibrium constants was examined to estimate the apparent thermodynamic functions (Delta H, DeltaS and Delta G) for extraction reaction. Lead(II) was successfully separated from commonly associated metal ions such as Bi(III), Hg(II), Cr(VI), Cd(II), Zn(II), Al(III), Ca(II), Ba(II) and from binary and ternary mixtures. The method was extended for determination of lead(II) in real samples.     

肉苁蓉中多酚类物质提取条件的优化及含量的测定

本研究建立了紫外-可见分光光度法测定肉苁蓉中多酚类物质(以没食子酸计)含量的方法。当乙醇浓度为70%、温度为60℃、提取时间为30min、料液比为1:20时,肉苁蓉中多酚类物质(以没食子酸计)的提取效果最好。同时肉苁蓉样品中多酚类物质(以没食子酸计)的平均质量百分比为0.2422%。精密度、稳定性和加标回收结果显示该方法可行可靠。     

粉煤灰提取白炭黑和氧化铝的研究

粉煤灰是我国当前排量最大的工业废渣之一,年排渣量已达3亿t以上,大量堆积的粉煤灰会对自然生态环境造成严重的危害。综合利用粉煤灰,实现粉煤灰的资源化利用,对于治理粉煤灰的污染具有十分重要的意义。文章提出先采用碱液常压浸出粉煤灰,生产白炭黑,然后采用碱石灰烧结法生产氧化铝,可实现粉煤灰的经济综合利用。研究表明：用苛性碱液在常压（＜125 ℃）下浸取粉煤灰45 min,粉煤灰中硅的提取率达到72.5 %以上,而氧化铝的总溶出率＜1.2 %;碳分浸取得到的硅酸钠溶液,可以生产氧化硅含量＞99 %的优质白炭黑,溶液中氧化硅转化率＞98 %;浸取硅后的渣中氧化铝含量＞55 %,氧化硅含量＜20 %,铝硅比≥2.7,适宜采用碱石灰烧结法生产氧化铝。碱石灰烧结法适宜的配方为：碱比 0.95～1.0,钙比 1.8～2.0;烧结温度宜为1 200～1 250 ℃;熟料溶出温度75～85 ℃,时间10～20 min,氧化铝回收率＞86 %。综合利用粉煤灰生产白炭黑和氧化铝,经济效益和社会效益显著。     

Extraction and recovery of chromium from electroplating sludge

This work reports a study of the extraction and recovery of chromium from the wastes (class I dangerous) generated by a galvanic manufacturer. Commercial HCl at room temperature was employed, and the conditions of the extraction process were optimized according to a sequential experimental design, which also included the acid concentration and contact time as variables. The best extraction conditions (80% v/v; 30 min; 97.6% Cr) for the chromic sludge were chosen in order to make the recovery process economically feasible. After each extraction, the residue was submitted to leaching essays, to assess environmental risks. It was found that sludge could be characterized as no longer dangerous. In the recovery study, a simple and low-cost technique was evaluated for selectivity based on an oxidation step with hydrogen peroxide. A 2(3) factorial design to assess the influence of oxidation time (min), temperature ( degrees C) and peroxide amount (mol/L) was employed. The best conditions, yielding a chromium recovery of about 92%, were a time of 60 min, a temperature of 60 degrees C and 2.1 mol/L peroxide. Additional essays revealed that the same result could be obtained with more economic conditions (40 min, 1.4 mol/L peroxide and 60 degrees C). This technique proved not only effective in comparison with existing alternatives, but also low costing.     

Extraction of Radionuclides from Alkaline and Carbonate Media

The review substantiates the desirability of developing spent nuclear fuel reprocessing technologies alternative to the Purex process. The practical use of radiochemical technologies based on alkaline and carbonate media, such as extraction of radiocesium from alkaline high-level waste and CARBEX process, is considered. Extraction of actinides with aliphatic amines, β-diketones, phenol derivatives (alkylpyrocatechols, aminomethylphenols, alkylphenol oligomers, calixarenes), and carboxylic acids, as well as extraction in two-phase aqueous systems based on water-soluble polymers, is discussed. The extraction of technetium is considered separately.     

Extraction of antioxidants from olive mill wastewater and electro-coagulation of exhausted fraction to reduce its toxicity on anaerobic digestion

Liquid-liquid extraction was used in order to recover phenolic compounds from centrifuged olive mill wastewater (OMW), a polluting by-product of olive oil production process, and to reduce their toxicity for a subsequent aerobic or anaerobic digestion. Phenolic compounds were identified in untreated and treated OMW by gas chromatography coupled to mass spectrometry (GC-MS). The experimental results of ethyl acetate extraction showed that the monomers recovery efficiency was over 90%. This pre-treatment resulted in the removal of the major LMM phenolic compounds and a small part of HMM polyphenols. The aerobic treatment of the exhausted OMW fraction removed 78.7% of the soluble COD. In the case of anaerobic digestion at OLR ranged from 1 to 3.5 gCOD l(-1)day(-1), methanisation process exhibited high methane yield as 0.3 l CH4 produced per g COD introduced and high COD removal (80%). However, a disruption of the process was observed when the OLR was increased to 4.5 gCODl(-1)day(-1). A pre-treatment by electro-coagulation resulted in decreasing the toxicity and enhancing the performance of methanisation operated at higher OLR from 4 to 7.5 gCODl(-1)day(-1).     

分形噪声中谐波信号的提取

本文提出一种分形噪声中谐波信号的提取算法。它利用小波变换对1／f噪声的白化作用,结合自适应自调谐滤波器组,在小波域实现了分形噪声与谐波信号的分离。仿真结果表明,该算法能够有效地抑制分形噪声,显著地提高信噪比。     

Kinetics of Thermal Extraction from Soot

An experimental result on the extraction of fullerene from graphite evaporated soot by thermal sublimation in vacuum is reported. the kinetics shows a complex time dependence, an indication of a fullerene diffusion from the interior of the soot granule to the surface of the granule in order to sublime. the total fullerene yield by thermal extraction is proven to be equal to a better than the yield from the commonly used organic solvent extraction process. In addition, thermal extraction is an ecologically conscious process, while the solution extraction is not.