A fast, single column extraction chromatography method for the isolation of Neodymium from iron-rich materials prior to radiogenic isotope ratio measurements

A novel separation method is described for the separation of Nd from Fe-rich, silicate samples in view of isotopic analyses. The procedure is based on the synergistic enhancement of the...

A tandem-column extraction chromatography for Nd separation: minimizing mass-independent isotope fractionation for ultrahigh-precision Nd isotope-ratio analysis

The short-lived 146Sm-142Nd isotope system traces key early planetary differentiation processes that occurred during the first 500 million-years of solar system history. The variations of 142Nd/144Nd in terrestrial samples, typically...

Impact of draw velocity profile on footprint definition for primary rock

In block/panel caving mines the footprint geometry and the undercut level height are key planning elements that have a bearing on the project final value. Selection of these parameters obviously depends on the economic objective, but it is also strongly influenced by rock mass characteristics that define column extraction capacity from draw points. This paper presents a simple methodology that allows defining the footprint and the best height of draw (BHOD) based on column extraction velocities, which are defined with the aim of controlling mass rock dynamic response while caving is propagated. The proposed methodology can be used by industry because of the ease of application. A study case is presented for a block model which is evaluated by both the proposed methodology and nominal profit estimation.

Optimized Batrachochytrium dendrobatidis DNA extraction of swab samples results in imperfect detection particularly when infection intensities are low

Accurate detection of the amphibian fungal pathogen Batrachochytrium dendrobatidis (Bd) is critical for wildlife disease research; however, false negatives in detection do occur. Here we compared different DNA extraction methods to determine the threshold for Bd detection and identify an optimal extraction method to improve detection and quantification of the pathogen. We extracted both lab-created cell suspension standards using PrepMan Ultra, Chelex resin, and 3 spin column DNA extraction kits (Qiagen DNeasy Blood and Tissue, Zymo Quick DNA miniprep, and IBI gMAX mini kit), and further compared extraction methods using field-collected samples. We found that when extracting Bd DNA from cells in lab-created culture, the spin column extraction methods and PrepMan Ultra were equivalent, while the resin method detected higher Bd DNA quantities, especially at higher loads. However, when swabs from live animals were analyzed, low Bd quantities were more than twice as likely to be detected using a spin column extraction than with the PrepMan Ultra extraction method. All tested spin column extraction methods performed similarly across both field and lab samples. Samples containing low Bd quantities yielded inconsistent detection and quantification of Bd DNA copies regardless of extraction method. To manage imperfect detection of Bd, we suggest that presence/absence analyses are more informative than attempting to quantify Bd DNA when quantities are low. Overall, we recommend that a cost-benefit analysis of target species susceptibility and epidemiology be taken into consideration when designing an experiment to determine the most appropriate DNA extraction method to be used, because sometimes detecting low Bd quantities is imperative to the study, whereas in other situations, detecting low DNA quantities is less important.

Application of calixpyrrole modified silica for the removal of 4-chlorophenol from aqueous media

In this research, calixpyrrole modified silica (III) was synthesized and characterized by Fourier transform infrared spectroscopy (FTIR), thermal gravimetric analysis (TGA) and scanning electron microscope (SEM) techniques. The synthesized material was used as an extractant for the removal of 4-chlorophenol from aqueous solution. Its efficiency was examined through both batch and column extraction methods. The effects of temperature, pH, initial chlorophenol concentration and mass of the adsorbent were examined using removal efficiencies. Initial concentration and quantity of adsorbent show a noticeable influence on the uptake capacity of the adsorbent. The kinetics and thermodynamics of chlorophenol removal from aqueous media were also investigated. Kinetic studies indicated that the extraction data can be best represented by pseudo second order model. Column extraction data were analyzed through Thomas, Yoon-Nelson and Yan et al. models to calculate kinetic coefficients and maximum sorption capacity of the modified silica (III). The adsorbent silica was regenerated by acid treatment without changing its properties.

Studies on purification of 89Sr from irradiated yttria target by multi-column extraction chromatography using DtBuCH18-C-6/XAD-7 resin

Abstract89Sr is being produced using yttria target via the nuclear reaction89Y(n,p)89Sr in Fast Breeder Test Reactor (FBTR), Kalpakkam. The isotope89Sr is a pure beta emitter with a half-life of 50.53 days which is useful mainly for bone pain palliation in patients with bone metastases. The existing method for processing the irradiated yttria target to obtain the pure89Sr source involves separation of the bulk yttrium target by solvent extraction using TBP-HNO3followed by purification of89Sr source by cation exchange chromatography technique using Dowex resin. The study described here involves the selective extraction and purification of89Sr by multi-column extraction chromatography technique using the Sr-specific crown ether, DtBuCH18C6 (CE) coated onto an XAD-7 resin matrix for superior separation and increased yield compared to single column technique. The89Sr source thus purified from the irradiated yttria target is free from other radionuclidic impurities produced during the target irradiation i.e.88Y,65Zn,139,141Ce,154Eu and160Tb.