Automation, leaching

Muller, P.J., and Schneider, R. (1993) An automated leaching method for the determination of opal in sediments and particulate matter. Deep-Sea Res. 40, 425 144. 

In liquid-solid extraction (LSE) the analyte is extracted from the solid by a liquid, which is separated by filtration. Numerous extraction processes, representing various types and levels of energy, have been described steam distillation, simultaneous steam distillation-solvent extraction (SDE), passive hot solvent extraction, forced-flow leaching, (automated) Soxh-let extraction, shake-flask method, mechanically agitated reflux extraction, ultrasound-assisted extraction, y -ray-assisted extraction, microwave-assisted extraction (MAE), microwave-enhanced extraction (Soxwave ), microwave-assisted process (MAP ), gas-phase MAE, enhanced fluidity extraction, hot (subcritical) water extraction, supercritical fluid extraction (SFE), supercritical assisted liquid extraction, pressurised hot water extraction, enhanced solvent extraction (ESE ), solu-tion/precipitation, etc. The most successful systems are described in Sections 3.3.3-3.4.6. Other, less frequently... 

Adoption of continuous schemes for leaching and solution purification, allowing more automation and lower operating costs... 

Grabek et al. [22] has reported a semi-automated isolation procedure and the detection of"strontium in soils. The strontium is leached from soil by employing a water suspension of Amberlite IR-120 and then separating strontium from other cations with Amberlite GC-400 or Dowex. 

Shade, C.W. Automated simultaneous analysis of monomethyl and mercuric Hg in biotic samples by Hg-thiourea complex liquid chromatography following acidic thiourea leaching. Environ. Set Technol. 2008, 42, 6604-6610. 

The designs described in Section 4.3.4 have been used either to leach the target analytes only and then proceed off-line with other steps of the analytical process, or to couple leaching on-line with other steps in order to automate the overall process as far as possible. 

The CUSAL-HPLC couple has been combined additionally with pre- or post-column derivatization. Thus, pre-column derivatization was used for the determination of colistin A and B in feeds following USAL, the analytes were derivatized with o-phthaldialdehyde/2-mercaptoethanol and separated by HPLC for fluorimetric detection [48]. The experimental set-up used is depicted in Fig. 4.1 OA. Another application of CUSAL-HPLC is the determination of A/-methylcarbamates in soils and food [49] (see Fig. 4.10B), where the analytes were also derivatized with o-phthaldialdehyde after separation for fluorescence-based monitoring. A number of steps of the process including leaching, filtration, solid-phase extraction, liquid chromatographic separation, post-column derivatization and fluorescence detection were performed on-line, all in an automated manner. 

Despite recent efforts toward settling operational conditions for metal and metalloid fractionation assays—in terms of concentration, pH, and temperature for each of the leaching reagents, sample weight/extractant volume ratio, extraction time, shaking protocol, analytical instrumentation, and phase separation method —conventional sequential extraction schemes lack automation and are inherently rather time consuming and laborious. This is the consequence of a number of steps needed for the separation, identification, and quantification of TEs in each fraction. For example, the SM T recommended protocol lasts more than 50 hours, whereas the operating time of Tessier s scheme approaches 20 hours. 

A. R. Leach, D. P. Dolata, and K. Prout, /. Chem. Inf. Comput. Sci., 30, 316 (1990). Automated Conformational Analysis and Structure Generation Algorithms for Molecular Perception. 

Leach AR and Prout K (1990) Automated conformational analysis directed conformational search using the A algorithm. J Comp Chem 11 1193-1205. 

The most extensively used macroporous resins are polystyrene-based ion-exchange resins. They are made of poly(styrene-co-divinylbenzene) with subsequent modification to arylsulphonic acids, quaternary ammonium salts or other derivatives mainly located on the internal surface of the pores [33,34]. This renders them accessible to munerous organic solvents including water and alcohols. Recently, these ion-exchange resins have had a revival for the immo-biUsation of ionic reagents [31,32] in automated synthesis. Macroporous beads have also been used for the immobihsation of catalysts [5,7] however, leach-... 

Nineteen AA were detected in beer samples derivatized with napthalene 23-dicarboxaldehyde (NDA) and cyanide (CN ) by capillary zone electrophoresis (CZE) with electrochemical detection Under the optimum conditions, the limits of detection (LODs) for individual AA were between 84 and 893 amol. An interesting method recently developed by Ruiz-Jimenez and Luque de Castro reported the determination of BA in nine solid food samples using a full-automated method based on pervaporation coupled online with CE and indirect UV detection. The pervaporator allowed leaching, formation of the volatile analytes, and their removal by evaporation and diffusion through a membrane. The isolated analytes were injected online into the CE system while the solid matrix remained in the pervaporator. With this approach, BA have been determined in fish, meat, and sausage, with LODs ranging between 0.2 and 0.6 fig/mL. 

Leaching Add a new jarosite filter Add a new jarosite tank Upgrade pumps/piping lines where necessary Automate Convert the existing basics filter to jarosite and install a new basics filter... 

Building a new plant for the different acid leaching stages Increase the residue filtration capacity Expansion of the present purification installation Automation of the leaching and purification processes... 

Operation of the Kidd electrolytic zinc plant commenced in 1972 with a cellhouse capacity of 105,000 tonnes of zinc cathode. The original cellhouse layout consisted of 42 parallel rows for a total of 588 cells. As leaching capacity increased, the cellhouse was expanded to 630 cells. Zinc cathode was manually stripped from plant start-up until the development of a mobile automated stripping system in 1994. Machine development continued until a second unit was placed in production in 1996, from which point, 60 % of the cellhouse was being stripped with the automated system. The final phase of the project was implemented in 1999 with the commissioning of two more automated strippers. This paper describes the implementation of the automated stripping system and its impact on cellhouse productivity. 

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