nitrogen-dioxide and potassium-hydroxide

A technology of obtaining active carbon from plum stones by chemical activation with KOH is described. The effect of carbonisation temperature as well as activation procedure on the textural parameters, acid-base character of the surface and sorption properties of active carbons has been checked. The sorption properties of the activated carbons obtained were characterised by determination of nitrogen dioxide adsorption in dry and wet conditions. The final products were microporous activated carbons of well-developed surface area varying from 2174 to 3228 m(2)/g and pore volume from 1.09 to 1.61 cm(3)/g, showing different acid-base character of the surface. The results obtained in our study have proved that a suitable choice of the carbonisation and activation procedure for plum stones can produce activated carbons with high capacity of nitrogen dioxide, reaching to 67 and 42 mg NO(2)/g in dry and wet conditions, respectively. The results of our study have also shown that the adsorption ability of carbonaceous sorbents depends both on the method of preparation as well as on the textural parameters and acid-base properties of their surface.

Topics: Adsorption; Carbon; Charcoal; Hydroxides; Nitrogen Dioxide; Porosity; Potassium Compounds; Surface Properties

Nitrogen dioxide is formed during delivery of inhaled nitric oxide for the treatment of patients with pulmonary hypertension. Soda lime has been shown to absorb nitrogen dioxide. We tested three different commercially available soda lime preparations (Sodasorb, Drägersorb 800 and Sofnolime) for their efficacy in absorbing nitrogen dioxide and nitric oxide during simulated nitric oxide inhalation. All soda lime preparation absorbed nitrogen dioxide (15%, 24% and 34%, respectively). To test if this difference could be attributed to the potassium hydroxide (KOH) content of the different preparations, two other preparations with a higher (3.0% and 7.3% w/w, respectively) KOH content were tested and we found an increase in nitrogen dioxide removal up to 47% and 46%, respectively. We conclude that soda lime absorbed nitrogen dioxide during nitric oxide inhalation. This effect seemed to be moderate under simulated clinical conditions, but increased using soda lime with a higher KOH content. Nevertheless, we recommend continuous monitoring of inspired nitrogen dioxide concentration during clinical inhalation of nitric oxide.

Topics: Absorption; Administration, Inhalation; Calcium Compounds; Gas Scavengers; Humans; Hydroxides; Nitric Oxide; Nitrogen Dioxide; Oxides; Potassium Compounds; Sodium Hydroxide; Vasodilator Agents

Nitrogen dioxide (NO2) and sulphur dioxide (SO2) in air were sampled by the use of a Sep-Pak C18 cartridge impregnated with triethanolamine-potassium hydroxide. The trapped NO2 and SO2 were eluted with a 8 mM sodium carbonate-3 mM sodium hydrogencarbonate solution and simultaneously determined by ion chromatography. In the active sampling mode, NO2 was determined with 5.2% relative standard deviation at 95 ppb and SO2 was determined with 2.4-5.3% relative standard deviation at 54-184 ppb. The recoveries were 85-98% for NO2 and 91-105% for SO2. In the passive sampling mode, the average concentrations of NO2 and SO2 were determined with 2.4-6.8 and 2.8-7.9% relative standard deviation, respectively, at atmospheric levels for 6-24 days.

Topics: Air Pollutants, Occupational; Chromatography, Ion Exchange; Ethanolamines; Humidity; Hydroxides; Nitrogen Dioxide; Nitrous Oxide; Potassium; Potassium Compounds; Sulfur Dioxide