scholarly journals A silica gel-bound macrocycle system for the selective separation of toxic cadmium from metal-affluent aqueous matrix

2013 ◽  
Vol 11 (3) ◽  
pp. 341-347 ◽  
Author(s):  
Hiroshi Hasegawa ◽  
Ismail Rahman ◽  
Zinnat Begum ◽  
Yoshihiro Umehara ◽  
Teruya Maki ◽  
...  
Keyword(s):  
Molecular Recognition ◽  
Solid Phase Extraction ◽  
Natural Waters ◽  
Solid Phase ◽  
Selective Separation ◽  
Phase Extraction ◽  
Solution Ph ◽  
Retention Capacity ◽  
Flow Rates ◽  
Ph Range

AbstractAbstract Selective separation of cadmium(II) on a macrocycle immobilized solid phase extraction (SPE) system namely AnaLig Cd-01, and commonly known as molecular recognition technology (MRT) gel, have been examined. The MRT-SPE able to retain the cadmium from the metal-affluent aqueous matrix at the pH range of 2 to 8, and the captured species can be recovered via elution with 1 and 6 M HNO3. Besides the effects of solution pH and eluent concentration, the impacts of sample loading flow rates and coexisting matrix ions were also investigated and optimized. The Cd(II) retention capacity of the MRT-SPE was 0.26 mmol g-1, and it can be reused for more than 100 loading and elution cycles. The Cd(II) recovery attained from the metal-spiked natural waters was satisfactory (95.3–98.1%). However, the Cd(II) retention ability of the MRT-SPE was significantly decreased when excess of chelant remain in the aqueous waste matrix. Graphical abstract

Measurement of Free Desipramine in Serum by Ultrafiltration with Immunoassay

1992 ◽  
Vol 38 (12) ◽  
pp. 2468-2471 ◽  
Author(s):  
M J Hursting ◽  
G D Clark ◽  
V A Raisys ◽  
S J Miller ◽  
K E Opheim
Keyword(s):  
Solid Phase Extraction ◽  
Therapeutic Range ◽  
Serum Proteins ◽  
Solid Phase ◽  
Equilibrium Dialysis ◽  
Phase Extraction ◽  
Standard Laboratory ◽  
Ph Range ◽  
Phosphate Buffered Saline

Abstract We developed an ultrafiltration method for assaying free desipramine (DMI) in serum. An ultrafiltrate of DMI-containing serum was prepared by centrifugation through an Amicon Centrifree micropartition filter. Syva DMI solid-phase extraction (SPE) columns were used to extract the DMI from the serum and ultrafiltrate. The Syva monoclonal EMIT assay was used to quantify the DMI in the extract. In some experiments, the percent free DMI was quantified with radioactivity. Nonspecific losses of DMI in serum to the ultrafilter system were low (recoveries > 91%). Extraction of [3H]DMI from phosphate-buffered saline (to mimic serum ultrafiltrate) with the Syva SPE system was quantitative (recoveries of 98.4% +/- 4.6%). Free DMI concentrations, derived from serum containing 2.5-2500 micrograms/L DMI, were determined by ultrafiltration; results agreed well with values determined by equilibrium dialysis, the average percent of free DMI being 18.4% +/- 0.25% and 15.9% +/- 0.51%, respectively. To increase the sensitivity of the free DMI assay in the therapeutic range (total DMI 125-300 micrograms/L), we increased fourfold the ultrafiltrate volume applied to the SPE column. For free DMI at 11-130 micrograms/L, the within-run and between-run CVs for the ultrafiltration method were < 9% and < 15%, respectively. Binding of DMI to serum proteins decreased over the pH range 6.0-8.0, although temperatures between 20 and 28 degrees C did not affect binding. The ultrafiltration assay is fast, accurate, simple, and adaptable to standard laboratory instrumentation.

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