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Recovery Efficiency (recovery + efficiency)
Selected AbstractsSimple and rapid extraction, separation, and detection of alkaloids in beveragesJOURNAL OF SEPARATION SCIENCE, JSS, Issue 21 2008Christine L. Copper Abstract Implementation of an uncomplicated SPE process for the rapid extraction and preconcentration of the alkaloids, colchicine, strychnine, aconitine, and nicotine, from water, apple juice, and nonfat milk samples is presented. When coupled to analysis via micellar EKC (MEKC), the total analysis time per sample was less than 15 min for the water and juice samples and less than 20 min for the milk. The SPE process allowed for anywhere from a three to a fourteen-fold improvement in the LOD for each alkaloid when compared to detecting the alkaloids in a nontreated water sample matrix. Following SPE, the LODs for colchicine, strychnine, and nicotine were sufficient to meet levels from 150 to 5000 times more dilute than the LD50 for a 50 kg individual drinking 12 oz of a contaminated beverage. Aconitine, on the other hand, was detected at approximately the LD50 level. The percent recoveries for the SPE ranged from 37% to as high as 99%. Nicotine attained the highest recovery efficiencies, followed by colchicine, and finally, aconitine and strychnine, which were nearly identical. The greatest recovery efficiencies were achieved from apple juice and water, whereas nonfat milk yielded the lowest. [source] Evaluation of an internal positive control for Cryptosporidium and Giardia testing in water samplesLETTERS IN APPLIED MICROBIOLOGY, Issue 3 2003M. Warnecke Abstract Aims: An internal positive control for Cryptosporidium and Giardia monitoring was evaluated for use in routine water monitoring quality control. The control, known as ColorSeed C&G (BTF Pty Ltd, Sydney, Australia), is a suspension containing exactly 100 Cryptosporidium oocysts and 100 Giardia cysts that have been modified by attachment of Texas Red to the cell wall, allowing them to be differentiated from unmodified oocysts and cysts. The control enables recovery efficiencies to be determined for every water sample analysed. Methods and Results: A total of 494 water samples were seeded with ColorSeed C&G and with unlabelled Cryptosporidium and Giardia and then analysed. Additionally, the robustness of the ColorSeed labelling was challenged with various chemical treatments. Recoveries were significantly lower for the ColorSeed Texas Red labelled Cryptosporidium and Giardia than recoveries of unlabelled Cryptosporidium and Giardia. However, the differences in recoveries were small. On average ColorSeed Cryptosporidium recoveries were 3·3% lower than unlabelled Cryptosporidium, and ColorSeed Giardia recoveries were 4% lower than unlabelled Giardia. Conclusions: ColorSeed C&G is suitable for use as an internal positive control for routine monitoring of both treated and raw water samples. Significance and Impact of the Study: The small differences in recoveries are unlikely to limit the usefulness of ColorSeed C&G as an internal positive control. The ColorSeed labelling was found to be robust after different treatments. [source] Oil Spill Cleanup from Sea Water by Sorbent MaterialsCHEMICAL ENGINEERING & TECHNOLOGY (CET), Issue 12 2005A. Bayat Abstract Three sorbents were compared in order to determine their potential for oil spill cleanup. Polypropylene nonwoven web, rice hull, and bagasse with two different particle sizes were evaluated in terms of oil sorption capacities and oil recovery efficiencies. Polypropylene can sorb almost 7 to 9 times its weight from different oils. Bagasse, 18 to 45 mesh size, follows polypropylene as the second sorbent in oil spill cleanup. Bagasse, 14 to 18 mesh size, and rice hull have comparable oil sorption capacities, which are lower than those of the two former sorbents. It was found that oil viscosity plays an important role in oil sorption by sorbents. All adsorbents used in this work could remove the oil from the surface of the water preferentially. [source] Evaluation of rayon swab surface sample collection method for Bacillus spores from nonporous surfacesJOURNAL OF APPLIED MICROBIOLOGY, Issue 4 2007G.S. Brown Abstract Aim:, To evaluate US Centers for Disease Control and Prevention recommended swab surface sample collection method for recovery efficiency and limit of detection for powdered Bacillus spores from nonporous surfaces. Methods and Results:, Stainless steel and painted wallboard surface coupons were seeded with dry aerosolized Bacillus atrophaeus spores and surface concentrations determined. The observed mean rayon swab recovery efficiency from stainless steel was 0·41 with a standard deviation (SD) of ±0·17 and for painted wallboard was 0·41 with an SD of ±0·23. Evaluation of a sonication extraction method for the rayon swabs produced a mean extraction efficiency of 0·76 with an SD of ±0·12. Swab recovery quantitative limits of detection were estimated at 25 colony forming units (CFU) per sample area for both stainless steel and painted wallboard. Conclusions:, The swab sample collection method may be appropriate for small area sampling (10 ,25 cm2) with a high agent concentration, but has limited value for large surface areas with a low agent concentration. The results of this study provide information necessary for the interpretation of swab environmental sample collection data, that is, positive swab samples are indicative of high surface concentrations and may imply a potential for exposure, whereas negative swab samples do not assure that organisms are absent from the surfaces sampled and may not assure the absence of the potential for exposure. Significance and Impact of the Study:, It is critical from a public health perspective that the information obtained is accurate and reproducible. The consequence of an inappropriate public health response founded on information gathered using an ineffective or unreliable sample collection method has the potential for undesired social and economic impact. [source] Direct detection of bacterial pathogens in representative dairy products using a combined bacterial concentration-PCR approachJOURNAL OF APPLIED MICROBIOLOGY, Issue 6 2004K.A. Stevens Abstract Aims:, To develop a simple, rapid method to concentrate and purify bacteria and their nucleic acids from complex dairy food matrices in preparation for direct pathogen detection using polymerase chain reaction (PCR). Methods and Results:, Plain non-fat yogurt and cheddar cheese were each seeded with Listeria monocytogenes or Salmonella enterica serovar. Enteritidis in the range of 101,106 CFU per 11-g sample. Samples were then processed for bacterial concentration using high-speed centrifugation (9700 g) followed by DNA extraction, PCR amplification, and amplicon confirmation by hybridization. Bacterial recoveries after centrifugation ranged from 53 to >100% and 71 to >100% for serovar. Enteritidis and L. monocytogenes, respectively, in the non-fat yogurt samples; and from 77 to >100% and 69 to >100% for serovar. Enteritidis and L. monocytogenes, respectively, in the cheddar cheese samples. There were no significant differences in recovery efficiency at different inocula levels, and losses to discarded supernatants were always <5%, regardless of dairy product or pathogen. Conclusions:, When followed by pathogen detection using PCR and confirmation by amplicon hybridization, detection limits of 103 and 101 CFU per 11-g sample were achieved for L. monocytogenes and serovar. Enteritidis, respectively, in both product types and without prior cultural enrichment. Significance and Impact of the Study:, This study represents progress toward the rapid and efficient direct detection of pathogens from complex food matrices at detection limits approaching those that might be anticipated in naturally contaminated products. [source] Computer simulation of flow-sheets for the solvent extraction of uranium: a new route to delay the effect of chemical degradation of the organic phase during uranium recovery from acidic sulfate mediaJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 12 2009Alexandre Chagnes Abstract BACKGROUND: The extractants used in solvent extraction processes undergo degradation under thermal, chemical and radiolytical stresses. In the case of uranium plants, tri- n -octylamine, used as an extractant, slowly degrades into di- n -octylamine. Such degradation causes a gradual depletion of the uranium extraction isotherms and as a result, of the efficiency of uranium recovery from feed solutions. The present work highlights a new route to delay this depletion of the extraction efficiency, merely by optimizing the flow-sheets involved in the process. Five flow-sheets have been compared for uranium recovery from acidic sulfate media by a solution of 0.146 mol L,1 tri- n -octylamine in kerosene modified with 5% w/w 1-tridecanol and stripping with a 199 g L,1 Na2CO3 solution. These five flow-sheets include the classical counter-current flow-sheet with four mixers,settlers in extraction and three mixers,settlers in stripping and four unusual combined solvent extraction flow-sheets with two independent extraction stripping loops and with one or two feed inlets. RESULTS: Computer simulation supplied evidence of the strong influence of the studied flow-sheets on the sturdiness of the process. More precisely, the unusual combined solvent extraction flow-sheets appeared to be significantly more efficient than the classical counter-current one and it is shown that an advantage of this can be to delay the negative impact of gradual degradation of tri- n -octylamine on uranium recovery efficiency from acidic sulfate media. CONCLUSION: The replacement of classical counter-current flow-sheets with a unique extraction-stripping loop in unusual combined flow-sheets with two or more independent extraction-stripping loops and with one or more feed inlets is a fruitful approach to delay the periodic addition of fresh tri- n -octylamine necessary for counter-balancing the progressive degradation of the extraction solvent and, as a result, to delay the gradual depletion of the efficiency of uranium recovery. Copyright © 2009 Society of Chemical Industry [source] CD146-based immunomagnetic enrichment followed by multiparameter flow cytometry: a new approach to counting circulating endothelial cellsJOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 5 2008A. WIDEMANN Summary.,Background: Circulating endothelial cells (CECs) have emerged as non-invasive biomarkers of vascular dysfunction. The most widely used method for their detection is CD146-based immunomagnetic separation (IMS). Although this approach has provided consensus values in both normal and pathologic situations, it remains tedious and requires a trained operator. Objectives: Our objective was to evaluate a new hybrid assay for CEC measurement using a combination of pre-enrichment of CD146+ circulating cells and multiparametric flow cytometry measurement (FCM). Patients and methods: CECs were determined in peripheral blood from 20 healthy volunteers, 12 patients undergoing coronary angioplasty, and 30 renal transplant recipients, and blood spiked with cultured endothelial cells. CD146+ cells were isolated using CD146-coated magnetic nanoparticles and labeled using CD45,fluorescein isothiocyanate and CD146,PE or isotype control antibody and propidium iodide before FCM. The same samples were also processed using CD146-based immunomagnetic separation as the reference method. Results: The hybrid assay detected CECs, identified as CD45dim/CD146bright/propidium iodide+, with high size-related scatter characteristics, and clearly discriminated these from CD45bright/CD146dim activated T lymphocytes. The method demonstrated both high recovery efficiency and good reproducibility. Both IMS and the hybrid assay similarly identified increased CEC levels in patients undergoing coronary angioplasty and renal transplantation, when compared to healthy controls. In patients, CEC values from these two methods were of the same order of magnitude and highly correlated. Bland,Altman analysis revealed poor statistical agreement between methods, flerrofluid,FCM providing higher values than IMS. Conclusion: This new hybrid FCM assay constitutes an accurate alternative to visual counting of CECs following CD146-based IMS. [source] Toxico-kinetics, recovery efficiency and microsomal changes following administration of deltamethrin to black Bengal goatsPEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 3 2001Sanis Juliet Abstract A study of the toxico-kinetics, recovery percentage from different substrates, cytotoxicity and role of cytochrome P450 and b5 of liver microsome in the metabolism of deltamethrin were carried out in female black Bengal goat. The ALD50 value of deltamethrin in goat by intravenous route lies between 0.2 and 0.6,mg,kg,1. Intravenous disposition kinetics using a dose of 0.2,mg,kg,1 showed that the maximum blood concentration of deltamethrin was recorded at 0.5,min, followed by rapid decline, and a minimum concentration was detected at 6,min after administration. The following values were obtained,:,Vdarea 0.148 (±,0.02) litre,kg,1; t1/2 (,) 0.22 (±,0.02),min; t1/2 (,) 2.17 (±,0.37),min; Kel 1.05 (±,0.24) min,1; AUC 4.30(±,0.45),µg min,ml,1; ClB 0.05 (±,0.006) litre,kg,1 min,1; T,B 1.93 (±,0.58); fc 0.40(±,0.05). After 10,min, liver retained the maximum residue, and heart, adrenal gland, kidney, spleen, fat and brain also held the insecticide; liver, fat, heart and spleen retained residue after 30,min, and bone, liver and fat retained residue after 60,min of intravenous administration. Oral absorption of deltamethrin was poor and inconsistent, and approximately 65% of administered dose was recovered from faeces and gastrointestinal contents. The excretion of deltamethrin through urine was meagre, and only 0.01 and 0.013% of the administered dose was recovered after 3 and 5 days of oral administration respectively. All the tissues retained the residue after 3 days; while fat, rumen, reticulum, omasum, abomasum, large and small intestine and bone retained the residue after 5 days of oral administration; and the percentage recoveries were 1.73 and 0.027 respectively. Deltamethrin reduced the level of cytochrome P450 content of liver microsomal pellet of goat after 5 days of oral administration. Histopathological examination of liver, kidney, heart, spleen brain and lung sections of treated goats did not reveal any pathological changes. © 2001 Society of Chemical Industry [source] Development and validation of a simple thin layer chromatographic method for the analysis of artemisinin in Artemisia annua L. plant extractsBIOMEDICAL CHROMATOGRAPHY, Issue 5 2008Els Marchand Abstract Owing to the development of parasite resistance to standard antimalarial treatments like chloroquine and sulfadoxine,pyrimethamine, the demand for Artemisia annua, a key ingredient for new and highly effective antimalarial drugs, is huge. Therefore selective and precise methods to determine the content of artemisinin in dry plant material and in raw impure extracts are needed. In this work a method is described for the clear separation and extraction of artemisinin from other plant components in the Artemisia annua L. plant by thin-layer chromatography (TLC). To obtain optimal extraction and recovery efficiency, several parameters were evaluted, including choice of extraction solvent, TLC plate type and sensitivity between UV and visible light. Method validation was performed on both the dry plant material and non-purified plant extracts. Toluene presented the highest extraction efficiency compared with petroleum ether, hexane and methanol. Reversed-phase plates showed more concentrated spots than normal-phase plates, while the sensitivity of the analysis in UV was comparable to that in visible light but less precise. The impure plant extracts were analyzed by both TLC and HPLC-UV at 215 nm and both methods met the requirements for linearity, selectivity, precision and accuracy. Hence, the proposed TLC method can easily be used for both qualitative and quantitative control of the raw plant extract in areas where advanced methods are scarce. Copyright © 2007 John Wiley & Sons, Ltd. [source] | |||||||||||||