Photometric determination of microgramme quantities of 1,3,5-trinitro-1,3,5-triazacyclohexane in air

1984 ◽  
Vol 49 (6) ◽  
pp. 1464-1467
Author(s):  
Stanislav Eminger ◽  
Marie Vejrostková
Keyword(s):  
Sulphuric Acid ◽  
Silica Gel ◽  
Photometric Determination ◽  
Sampling Tube ◽  
Disulphonic Acid ◽  
Activated Silica Gel

A method is suggested for the determination of 1,3,5-trinitro-1,3,5-triazacyclohexane in workroom atmosphere. The substance is trapped in a sampling tube containing glass microfibres and activated silica gel, decomposed with sulphuric acid to give formaldehyde, the latter is reacted with 1,8-dihydroxynaphthalene-3,6-disulphonic acid, and the derivative of dibenzoxanthiliumtetrasulphonic acid formed is determined protometrically at 580 nm.

Highly-sensitive and rapid determination of protocatechuic aldehyde based on the electrochemical enhancement of activated silica gel

2014 ◽  
Vol 6 (21) ◽  
pp. 8738-8743
Author(s):  
Xuerong Chen ◽  
Kangbing Wu ◽  
Yikai Zhou
Keyword(s):  
Silica Gel ◽  
Electrochemical Method ◽  
Rapid Determination ◽  
Signal Enhancement ◽  
Protocatechuic Aldehyde ◽  
Highly Sensitive ◽  
Activated Silica Gel

A highly-sensitive electrochemical method was developed for the determination of protocatechuic aldehyde (PAL) based on the remarkable signal enhancement of activated silica gel.

scholarly journals SILICA GEL MODIFIED WITH 1,2-NAPHTHOQUINONE THIOSEMICARBAZONE FOR SORPTION-PHOTOMETRIC DETERMINATION OF MERCURY (II)

2017 ◽  
pp. 52-55
Author(s):  
M. Zui ◽  
S. Diduk
Keyword(s):  
Silica Gel ◽  
Natural Water ◽  
Water Samples ◽  
Natural Waters ◽  
Photometric Determination ◽  
Test Method ◽  
Relative Standard ◽  
Edta Solution ◽  
Effects Of Ph

A sorption-photometric test method for preconcentration and determination of mercury (II) was developed using silica gel modified with 1,2-naphthoquinone thiosemicarbazone. Modification of silica gel with a reagent was carried out from the chloroform-hexane solution for 3 hours. Pocket photometer was used for the measurement of reflected (transmitted) light from silica modified after sorption of thiosemicarbazonate of Hg(II). The adsorption capacity of the sorbent has been found to be 35 μmol g-1 for 1,2-naphthoquinone thiosemicarbazone. The effects of pH, sorption time, the volume of aqueous solution were studied. In the optimal conditions (pH 3.0; 5 min; 25°C) the extraction recovery of mercury is 90–95%. The range of concentrations of mercury (ІІ) is 50–600 µg L–1, the detection limit (S/N = 3) is 23 µg L–1. The method is tested in the model tap and natural water samples, relative standard deviation for 50 μg L−1 of Hg(II) is below 9.0 % (n = 3). The interference effect of the most common heavy metals in natural water, as Fe (III), Zn (II) and Mn (II) ions were studied. The EDTA solution was added for the binding of these metals, which forms strong colorless complexes with EDTA. We have shown that in the presence of 0,01 M EDTA solution Fe (III), Zn (II) and Mn (II) ions, each up to 500 μg L−1, do not interfere with the determination of mercury (II) at its content of 50 μg L−1. The method can be used for the determination of mercury in the sewage of various industries and natural waters with its high content. The proposed method is inexpensive, simple, fast, and environmentally friendly for the determination of the micro quantities of mercury (II) in the water samples.

Fluorimetric determination of traces of uranium(VI) in brines and iron(III) oxides using separation on an activated silica gel column

1992 ◽  
Vol 264 (1) ◽  
pp. 115-119 ◽  
Author(s):  
J. de Pablo ◽  
L. Duro ◽  
J. Giménez ◽  
J. Havel ◽  
M.E. Torrero ◽  
...  
Keyword(s):  
Silica Gel ◽  
Fluorimetric Determination ◽  
Activated Silica Gel

A sulphuric acid-impregnated silica gel clean-up procedure for the determination of n-alkanes migration from paraffin based paper packaging into cheddar cheese

2012 ◽  
Vol 134 (1) ◽  
pp. 405-411 ◽  
Author(s):  
Davinson Pezo ◽  
Magdalena Wrona ◽  
Angel Rodriguez-Lafuente ◽  
Cristina Nerin
Keyword(s):  
Sulphuric Acid ◽  
Silica Gel ◽  
Cheddar Cheese
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