A surface-modified silica gel has been developed for the pre-concentration of arsenite from natural waters. The reaction of silica gel with (3-mercaptopropyl)trimethoxysilane produces a mercapto-modified silica gel with a silver capacity of ca. 0.9 mmol g–1. This material selectively removes arsenite from samples that also contain arsenate, monomethylarsonate and dimethylarsinate, and can be employed for both the column and batch pre-concentration of arsenite. Under column and batch conditions recoveries of ca. 96 and 94% are obtained but reproducibility is better for the column technique.


Preconcentration of germanium on mercapto-modified silica gel
Gokturk, G; Delzendeh, M; Volkan, Mürvet (2000-07-14)
A simple method for the determination of ultra-trace amounts of germanium in natural waters has been developed. Germanium was preconcentrated using silica having mercapto functional groups, namely mercapto silica and determined by hydride generation flame atomic absorption spectrometry (HGAAS). Utilising mercapto silica, satisfactory recovery values (> 95%) were obtained at natural pH, for germanate concentrations as low as 50 ng 1(-1) Considering the highest preconcentration factor (400-fold) obtained, the...
Selective methane bromination over sulfated zirconia in SBA-15 catalysts
Yılmaz, Ayşen; Üner, Deniz (2009-04-15)
Methane activation via bromination can be a feasible route with selective synthesis of mono-bromomethane. It is known that the condensation of brominated products into higher hydrocarbons can result in coking and deactivation in the presence of di-bromomethane. In this study, selective production of methyl bromide was investigated over sulfated ZrO2 included SBA-15 structures. It was observed that the higher the ZrO2 amounts the higher the conversion, while the catalyst remained >99% selective for the monob...
Speciation and preconcentration of inorganic tellurium from waters using a mercaptosilica microcolumn and determination by hydride generation atomic absorption spectrometry
Korez, A; Eroglu, AE; Volkan, Mürvet; Ataman, Osman Yavuz (2000-12-01)
A separation-preconcentration method utilising a mercapto-modified silica microcolumn was developed for the determination of trace amounts of Te(rv) and Te(VI) in waters by hydride generation atomic absorption spectrometry. Bottled drinking water, tap water and sea-water samples were spiked with sub-ng ml(-1) concentrations of Te(IV) and the spiked solutions were subjected to the mercapto-modified silica microcolumn separation and enrichment procedure. The spike recovery values varied between 86 and 114%. I...
Synthesis, characterization and application of a novel mercapto- and amine-bifunctionalized silica for speciation/sorption of inorganic arsenic prior to inductively coupled plasma mass spectrometric determination
Boyacı, Ezel; Shahwan, Talal; Eroglu, Ahmet E. (2011-09-15)
A bifunctional sorbent, (NH(2) + SH)silica, containing both amine and mercapto functionalties was prepared by modification of silica gel with 3-(triethoxysilyl)propylamine and (3-mercaptopropyl)trimethoxysilane. In addition to the bifunctional sorbent, silica gel was modified individually with the functional mercapto- and amino-silanes, and the mono-functional sorbents, namely (SH)silica and (NH(2))silica, were also mechanically mixed ((NH(2))silica +(SH)silica) for the sake of comparison of sorption perfor...
Comparison of TOC concentrations by persulphate UV and high temperature catalytic oxidation techniques in the Marmara and Black Seas
Tuğrul, Süleyman (Elsevier BV, 1993-01-01)
Total organic carbon (TOC) concentrations were determined in the Marmara Sea and both oxic and anoxic waters of the Black Sea, using the Shimadzu high-temperature catalytic oxidation technique and the Technicon persulphate-UV oxidation method. The TOC values in the deep waters of the Marmara Sea ranged between 60 and 73 μ MC by the Shimadzu technique and from 40 to 50 μMC by the Technicon method. The TOC values obtained by both methods in the deep anoxic waters of the Black Sea varied between 105 and 130 μM...
Citation Formats
A. HOWARD, M. Volkan, and O. Y. Ataman, “SELECTIVE PRECONCENTRATION OF ARSENITE ON MERCAPTO-MODIFIED SILICA-GEL,” ANALYST, pp. 159–162, 1987, Accessed: 00, 2020. [Online]. Available: