In this paper we report first results from the developed cavity ring-down spectrometer for application in human breath analysis for the diagnostics of diabetes and later for early detection of lung cancer. Our cavity ring-down spectrometer works in UV region with pulsed Nd:YAG laser at 266 nm wavelength. First experiments allow us to determine acetone and benzene at the level bellow ppm. In our experiment, first results from breath samples from volunteers after doing different activities were collected and examined. Influence of the smoking on the breath signals also was examined.
In this paper we report the current stage of the development of a cavity ring-down spectrometer (CRDS) system using exhaled human breath analysis for the diagnostics of different diseases like diabetes and later lung cancer. The portable CRDS system is made in ultraviolet spectral region using Nd:Yag laser 266 nm pulsed light. Calibration of the CRDS system was performed using generated samples by KinTek automated permeation tube system and self-prepared mixtures with known concentration of benzene and acetone in air. First experiments showed that the limits of detection for benzene and acetone are several tens of ppb.
This paper is devoted obtaining the threshold of the credibility of the solution by means of Tikhonov's regularization method in case of spectral lines, emitted from microsize plasma sources. The reliability of Tikhonov algorithm was verified by means of solving model tasks with different ratio between instrumental function and measured profile and, with different levels of noise.
In this paper we show our first results of research for creation a detector for benzene vapor and possibly other volatile organic compounds detection in air based on Zeeman atomic absorption technique. First the detailed study of benzene absorption spectra with high resolution spectrometer Jobin-Yvon 1000M was done. The absorption spectra of benzene were registered in the spectral range from 200-900 nm. More detailed analysis was done for the 240 – 260 nm spectral range to test a possibility to detect benzene by means of emission line of 254 nm of mercury.
High-frequency electrodeless light sources (HF EDLS) are widely used as bright radiators of narrow and intensive atomic and ionic spectral lines, covering the spectrum from VUV to IR. Main characteristics of HF EDLS are high emitted spectral line intensity, long service life, and in general, narrow spectral line shapes because of low-pressure of filling elements. In this work we give a short overview of the use of HF EDLS, containing Hg, Te, Se, Zn, Pb, As, Sb, Bi, Tl, In, Cd, Sn, in Zeeman Atomic absorption devices for assaying natural, drinking, waste and technical water as well as air, soil, food products and biological samples. The first steps are made for optimization of Ge, Ga, P, S, Ag, Cu HF EDLS. Enhanced detection limits are obtained in comparison with hollow cathode lamps.
The paper is devoted to problems of employment of high- frequency electrodeless lamps as ultra violet (UV) and vacuum ultra violet (VUV) light sources. Some aspects of lamp preparation technology for UV and VUV are considered. The technology, developed in our laboratory, allows to prepare HFEL-s filled with wide spread of chemical elements. Our experience shows that most important filling elements for UV and VUV spectral regions are Zn, Cd, Hg, Se, As, Sn and Pb, Sb, Bi, Tl, Te, I, H, Hg-Cd, Hg-Zn, Se-Te. The requirements for generators are discussed. Some important spectral characteristics of lamp examples are presented.
The high-frequency electrodes light sources (HFELS) are widely used as bright radiators of narrow and intensive spectral lines covering spectral region from VUV to IR. In this work we shall give a short overview of our experience in preparation of HFELS, containing He, H, Rb, Hg, Zn, Pb, As, Sb, Bi, Tl, Hg-Cd, Hg-Zn, Hg-Cd-Zn, Se-Te for different applications. Special attention would be paid for HFELS use in Zeeman mercury analyzer, in Atomic absorption analyzer and Angle and glass refractive index measurement system.