Propan-2-ol. Determining in workplace air with gas chromatography

Propan-2-ol is an easily volatile, colourless liquid with a pungent characteristic odour. In industry it is used as a solvent and a dewatering, cleaning and disinfecting agent. Propan-2-ol has an irritating and narcotic effect. It may cause drowsiness or dizziness. The aim of the study was to amend the PN-Z-04224-02:1992 standard in accordance with the requirements of European standard PN-EN 482. The method was developed in the range of concentrations from 1/10 to 2 of the MAC value. The tests were performed using a gas chromatograph (GC) with a flame ionization detector (FID) equipped with a capillary column HP-INNOWAX (60 m × 0.25 × mm, 0.15 µm). The method is based on adsorption of propan-2-ol vapours on activated carbon, desorption with a mixture of carbon disulphide and N,N-dimethylformamide and chromatographic analysis of the obtained solution. Using an HP-INNOWAX column for the analysis makes it possible to selectively determine propan-2-ol in the presence of carbon disulphide, N,N-dimethylformamide. The measurement range is 90/1 800 mg/m3 for a 9-L air sample. The detection limit of this method is 0.09 µg/ml and the limit of quantification is 0.28 µg/ml. The method is characterized by good precision and accuracy and meets the criteria listed in EN 482 for procedures for measuring chemical agents. The method may be used for assessing occupational exposure to propan-2-ol and the associated risk to workers’ health. The developed method of determining propan-2-ol has been recorded as an analytical procedure (see Appendix). This article discusses the problems of occupational safety and health, which are covered by health sciences and environmental engineering.

Leidenfrost evaporation of a single droplet of gasoline blends of ethanol

The increase in energy consumption is observed since the middle of the 20th century. At the same time, the International Energy Agency (IEA) forecasts a 50% increase in energy consumption by 2030. One of the ways to reduce the consumption of such fuels are small additions received from natural gas and renewable energy sources. Mixtures of alcohols with gasoline and diesel oil are produced. Their small additions allow for a certain share of energy from renewable sources without a noticeable change in the combustion characteristics of such fuels. The paper presents the studies on the evaporation of drops of gasoline with a total composition CnHn+2, where n = 5 to 7. Its components are distillation products of crude oil with a low flash point. It is a colourless liquid mixture which main components are: n-heptane, neohexane and cyclopentane. The evaporation characteristics of such a drop with the addition of ethanol are also given. The result of the conducted research is the loss of mass during the drop carried above the surface with temperature above the Leidefrost point.

Derivatives of cis-NPCl2 (NSOCl)2 and (NPCl2)2NSOCl, IVIsothiocyanato Derivatives of cis-NPCl2(NSOF)2

The compounds NPClNCS(NSOF)2 and NP(NCS)2(NSOF)2 are prepared by reaction of cis-NPCl2(NSOF)2 with KSCN. The mono(isothiocyanato) derivative obtained is a colourless liquid, consisting of two isomers in a ratio of 1:3.8; the bis(isothiocyanato) compound is a white crystalline solid.

IV. On β-lutidine

In the “Bulletin of the Chemical Society of Paris” for June 5, 1880 there appears a notice of a paper read before the Russian Chemical Society, by MM. Boutlerow and Wischnegradsky, m which they state, amono- other things, that by the action of alkalies on cinchonine they had obtained quinoline (chinoline) almost pure, and a volatile colourless liquid alkaloid boiling constantly at 166°, having the formula C 7 H 9 N ; and which they say appears to be identical with the base obtained by me in distilling cinchonine with potash, and also with the lutidine of Anderson. Of the identity of the base obtained by them with β-lutidine there can be no doubt; the boiling point (166°) given by them being to half a degree the mean of the range (163° to 168°) given by me in my “ Researches on Isomeric Alkaloids.”* With regard to the identity which they assume between lutidine and β-lutidine, it is evident that they have not seen my paper last quoted, or they would hardly have ignored the mass of facts which I have adduced to prove the isomerism, and not identity of the two bases.

4. On the Action of Heat on some Salts of Trimethyl-Sulphine. Part II

In the former paper on this subject, the authors stated that when hyposulphite (thiosulphate) of trimethyl-sulphine is heated to about 135° C., it loses sulphide of methyl to the extent of 23·58 per cent., the salt at the same time fusing to a clear colourless liquid. On cooling, this solidifies to a hard, very hygroscopic crystalline mass.

III. On fluoride of silver.—Part III

In this communication the author has finally shown that the action of iodine, under the influence of heat (including the process described by Kammerer, Phil. Mag. 1863, vol. xxv. p. 213, for the isolation of fluorine), does not liberate uncombined fluorine, but produces fluoride of iodine and iodide of silver, a double salt, composed of iodide of silver and fluoride of platinum, being produced at the same time by corrosion of the platinum vessels, if the temperature approaches a red heat. The fluoride of iodine produced is a highly volatile and colourless liquid, does not corrode mercury or red-hot platinum, corrodes glass at 60° Fahr., and crystals of silicon at a red heat, also platinum in contact with argentic fluoride in a state of fusion ; it instantly turns a deal splint black, fumes powerfully in the air, and is decomposed with violence by water into hydrofluoric and iodic acids, in accordance with the following equation:— IF 5 +3H 2 O = 5 HF+HIO 3 . It dissolves iodine, and is absorbed by that substance ; it is also absorbed either by argentic fluoride or iodide when those substances are cooled in its vapour, and may be expelled from them at a red heat. Its vapour quickly darkens the colour of a deal splint, and very gradually turns paraffin brown.

I. On boric ethide

When zincethyl in excess is brought into contact with tribasic boracic ether, (B{C 4 H 5 O 2 C 4 H 5 O 2 C 4 H 5 O 2 ), the temperature of the mixture gradually rises for about half an hour. If it be now submitted to distillation, it begins to boil at 94°C., and between this temperature and 140° a considerable quantity of a colourless liquid distils over. The distillation then suddenly stops, the thermometer rises rapidly, and, to avoid secondary products of decomposition, the operation should now be interrupted. The materials remaining in the retort solidify, on cooling, into a mass of large crystals, which are a compound of ethylate of zinc with zincethyl. On rectification, the distillate began to boil at 70°, but the thermometer rapidly rose to 95°, at which temperature the last two-thirds of the liquid passed over and were received apart. The product thus Collected exhibited a con­stant boiling-point on redistillation. Submitted to analysis, it yielded results agreeing with the formula B{C 4 H 5 C 4 H 5 C 4 H 5