Multichannel Spectrum Analysis Research Articles

FEATURES OF ELEMENTS ACCUMULATION IN FRUIT AND BERRY PLANTS CULTIVATED IN THE VICINITY OF ZELENOGORSK CITY, KRASNOYARSK REGION

The aim of the study is to identify the peculiarities of the elemental composition of berries (fruits) and leaves of raspberry (Rubus idaeus L.), rowan (Sorbus aucuparia L.), black currant (Ribes nigrum L.), sour cherry (Cerasus vulgaris L.), serviceberry (Amelanchier ovalis Medik.) collected in the vicinity of Zelenogorsk, Krasnoyarsk Region, with an assessment of their potential use as sources of elements, ecological safety of use, as well as patterns of distribution of elements between plants, soil, and the surrounding environment. The elemental composition was analyzed using the method of arc atomic emission spectroscopy with a multi-channel analyzer of emission spectra (DAES with MAES) after ashing. As a result, the presence of 30 elements was determined in the ash of the studied plants, 25 of which belong to trace elements, and 22 are (conditionally) essential. The belongingness of the minimum extremes of content to mostly odd ordinal numbers of elements in the Mendeleev table was established, while the maximum extremes belonged to even ones. It is proposed to represent the revealed regularities in the form of combinations of extrema with the corresponding serial numbers of atoms, which clearly indicates the plant's ability to concentrate certain chemical elements. Based on the degree of accumulation from the soil, which indicates the ability of plants to accumulate elements, the highest indicator for all studied species and their raw materials is K, for all raspberry and blackcurrant raw materials – Ca, for cherry and raspberry leaves with berries (fruits) and separately for cherry fruits – Mg, only for blackcurrant leaves with berries (fruits) – Ti, for blackcurrant leaves with berries (fruits) – Sr and Ag. The study identified only Ti and Ag as having a "strong accumulation" in the biological absorption of elements, while the others were common for vegetation. Raspberry was found to have the highest biogeochemical activity among the studied fruit and berry plants (regardless of the raw material), followed by blackcurrant. It is shown that the raw materials "leaves + berries (fruits)" in all the studied cases contain much more trace elements, in contrast to individual berries (fruits). The study demonstrated the potential use of these plant species as sources of macroelements and trace elements, including essential ones.

Multielement atomic emission analysis of rocks, soils, and ash of plants using argon arc two-jet plasmotron and multichannel analyzer of emission spectra (MAES)

A method of quantitative simultaneous determination of 23 trace elements (Ba, Be, Cu, Co, Cr, Ga, La, Mo, B, Ni, Pb, Sc, Sn, Sr, V, Y, Yb, Zn, Zr, Fe, Mn, P, Ti) and 6 macronutrients (Mg, Al, Si, Na, K, Ca) in soils, rocks and ash of plant material using atomic emission spectrometry is described. A two-jet argon arc plasmatron is used as the source of spectra excitation. The samples to be analyzed are introduced into the plasma flow jet by injection of an air suspension of a finely dispersed powder under gas (argon) pressure. A multichannel analyzer of emission spectra (MAES) is used for spectra recording. State standard samples of soils, rocks, and plant ash of various compositions and genesis are used as reference samples. The optimal conditions for excitation, registration of spectra and processing of the useful signal were determined to minimize the random and systematic errors of element determinations. Evaluation of the metrological characteristics, carried out using natural standard samples, revealed no significant systematic error. The relative standard deviation of the method ranges from 0.07 to 0.15, and the calculated value of the Student’s criterion for all the elements considered was shown to be less than the tabular value.

Analysis of aluminum alloys on a Polyvac E980 (Hilger Analytical) atomic emission spectrometer modified with a multi-channel analyzer of emission spectra (MAES)

A Polyvac E980 (Hilger Analytical) photoelectric vacuum optical emission spectrometer has been modified with a multichannel analyzer of emission spectra (MAES). The line of argon supply to the spark stand has been completely renewed. A precision mass flow controller with a microprocessor control unit has been installed to adjust the argon supply for different operation modes and fix the current values with the possibility of saving data for each spectrum. The microprocessor control unit coordinates the operation of the control lines and interrupts the operation of the spark generator when the stand is open or argon is absent. The modified vacuum spark spectrometer, originally designed for the analysis of iron-based alloys, has become suitable for determining the composition of non-ferrous alloys. Analytical programs have been developed for the rapid spectral analysis of AK12M2 and AK9ch aluminum alloys. The main methodological difficulty of the analysis is attributed to the necessity of monitoring high concentrations of silicon, copper, and iron along with the content of calcium impurity in the same sample. Calcium has a negative effect on the quality of castings, thus making the possibility of Ca determination an important motivation for the modification. After the preparatory work and the construction of calibration curves, the short-term and long-term repeatability of the results of spectral analysis of standard samples of aluminum alloys has been studied on the modified spectrometer. The results completely meet the standard requirements for determining the composition of aluminum alloys.

Comparison of the analytical capabilities of a facility with the arc double-jet argon plasmatron and a Grand-Potok complex in determination of the content of rare-earth elements in geological samples by atomic emission spectrometry

The method of atomic emission spectrometry with arc spectrum excitation provides determination of rare earth elements (REE) in geological samples by direct analysis of solid samples without a long-term preliminary sample preparation. Using the analysis of a rare-earth ore sample from the Tomtor niobium-rare-earth deposit as an example, we compared the analytical capabilities of a Grand Potok installation and a two-jet arc plasmatron (TJP) in combination with a DFS-458S spectrograph equipped with a multichannel emission spectrum analyzer (MAES). It is shown that a higher temperature of the TJP plasma (~7500 K) compared to that of the arc discharge (~5500 K) and the shift in the recording range of a DFS-458S spectrum to longer wavelengths (280 – 245 nm) provided a more reliable determination of REE using a larger number of analytical lines with lower detection limits. The correctness of the results of REE determination was confirmed by comparison with the data obtained by the ICP-MS method.

МУЛЬТИСЕНСОРНАЯ ОПТИЧЕСКАЯ СИСТЕМА НЕИНВАЗИВНОГО КОНТРОЛЯ КИСЛОРОДНОГО ОБЕСПЕЧЕНИЯ ТКАНЕЙ ЧЕЛОВЕКА ПРИ ФУНКЦИОНАЛЬНОЙ НАГРУЗКЕ

This work was performed using optical spectroscopy methods. The proposed method is based on the differences in the absorption spectra of oxyhemoglobin and reduced hemoglobin, as well as on the analysis of the response of the system using mathematical methods for processing multidimensional data. In the course of the work, a prototype of the diagnostic optical system for non-invasive monitoring of the oxygen supply of human tissues was created, which is based on a multi-channel optical spectrum analyzer. As a result of experimental studies, it was shown that each subject has his own individual, reproducible "image". The results of the study confirm the effectiveness of the proposed method for assessing the functional state of a person and the prospects for its use in practical medicine.

Chemical codes identification based on periodic dependences of chemical element distribution in biological objects

This work for the first time considers the periodic dependences of logarithm of chemical element concentration in human hair, animal hair, crude drugs and other objects of flora and fauna of Siberia on the atomic number in the periodic table. The hypothesis is put forward that the maxima on the constructed curves can serve as the original code reflecting their interrelation with various factors of a genetic and ecological nature. The samples of the animal origin, blood-sucking insects and fish are selected in Siberia (the Tomsk region), whereas the samples of the drug plants are taken in the Krasnoyarsk region. The diversity of the objects at issue and the regions for sampling is conditioned by the breadth of challenges this paper faces. The chemical element concentration in the objects is determined by the detection limit of the method applied (from 1· 10–5 to 104 µg/g and more). For convenience, this element concentration is represented as logarithmic charts. It is shown that periodic dependences of the living world of Siberia and Siberian regions are of the same genetic nature. In this research performed in the certified Environmental Monitoring Laboratory of the Tomsk Regional Core Facility Center of National Research Tomsk State University we use the Spectrometer “Grand” with a multichannel analyzer of emission spectra.

Reconstruction of groundwater levels to impute missing values using singular and multichannel spectrum analysis: application to the Ardabil Plain, Iran

ABSTRACT Groundwater-level time series often have a substantial number of missing values which should be taken into consideration before using them for further analysis, particularly for numerical groundwater flow modelling applications. This study aims to comprehensively compare two data-driven models, singular spectrum analysis (SSA) and multichannel spectrum analysis (MSSA), to reconstruct groundwater-level time series and impute the missing values for 25 piezometric stations in Ardabil Plain, northwest Iran. The reconstructed groundwater-level time series are assessed against the complete observed groundwater time series, while the imputed values are appraised against the artificially created gap values. The results show that both SSA and MSSA demonstrate a solid competency in imputation and reconstruction of groundwater-level data. However, depending on the spatial correlation between the piezometers, and the most suitable probability distribution function (pdf) fitted to the time series of each piezometer, the performance may vary from piezometer to piezometer.

Standardization of proton induced X-ray emission for analysis of trace elements in thick samples

This paper presents the standardization of proton induced X-ray emission (PIXE) technique for the analysis of trace elements in thick, standard samples. Three standard reference materials, titanium, copper, and iron base alloys, were used for the study due to their availability. The proton beam was accelerated up to 2.57 MeV energy by 5UDH-II tandem Pelletron accelerator, and samples were irradiated at different geometries and durations. Spectra were acquired using a multi-channel spectrum analyzer, and spectra analyses were done using GUPIXWIN software for determination of elemental concentrations of trace elements. The obtained experimental data were compared with theoretical data and results were found to be in close agreement.

Influence of Substrate Material on the Sensitivity of the Raman Lidar Technique for Detecting Traces of High-Energy Materials

Experimental results on the remote detection of surface traces of some high-energy materials are presented. The detection was performed with the use of a Raman lidar based on a narrow-linewidth excimer KrF laser and a multichannel spectrum analyzer with diffraction spectrograph and time-gated ICCD camera. The sensitivity of the lidar system is estimated for a detection range of 10 m. The influence of a substrate material on the detection sensitivity is analyzed.

Analysis of germanium dioxide using direct current arc atomic emission spectrometry with preconcentration of trace elements

A method for trace element concentration in the microwave accelerated reaction system MARS 5 is developed. The vapor-phase distillation was used to remove high-purity germanium dioxide matrix as volatile germanium tetrachloride (GeCl4). We specified operating conditions of the microwave system and chose a halogenating agent and its volume. The method of quantitative chemical analysis of germanium dioxide by direct current arc atomic emission spectrometry (DCA AES) was developed. The unit for analysis is equipped with a multichannel spectrum analyzer MAÉS produced by «VMK-Optoélektronika». We also determined the residual content of germanium in the resulting solutions after vapor-phase distillation. The limits for detection of 46 trace elements in DCA AES analysis of germanium dioxide with preconcentration of trace elements ranged from 0.5 ng/g to 1 μg/g. We carried out validation of the combined procedure using «spike test».

Elemental analysis of Siberian medicinal plants using arc atomic emission spectrometry with a multichannel analyzer of emission spectra

Study of macro- and microelement composition of the ash of plant raw materials revealed the prevailing matrix elements, their chemical form and content. It is shown that direct determination of the impurities in mineral residues by the method of arc atomic emission spectroscopy with a multichannel analyzer of emission spectra (MAÉS) is complicated by the impact of the macro component and its chemical form on the intensity of the spectral lines of the impurities. Introduction of a corrective additive is proved to eliminate this effect. A technique for measuring the mass fraction of macro elements and trace elements in plant ash is proposed and metrological certification of the procedure is carried out.

Multichannel Analyzers of Emission Spectra with Improved Characteristics in the 258–269 nm Region for the Grand Spectrometer

A fast multichannel analyzer of emission spectra (MAES) for the Grand spectrometer with a combined hybrid assembly of 12 BLPP-369M1 arrays (for the 190–350 nm spectral range) and one BLPP-2000 array (for the 258–269 nm spectral range) has been created. The minimum exposition time of the analyzer is 3 ms. It is shown that, at the base exposition time of 3 ms, the signal-to-noise ratio for the flashes of the analytical Au 267.595 nm line is a factor of 10 higher when recorded using the BLPP-2000 array as compared to the BLPP-369M1 array.

Remote detection of traces of high-energy materials on an ideal substrate using the Raman effect

We present experimental results on the remote detection of surface traces of some high-energy materials using a Raman lidar designed on the basis of an excimer KrF laser with a narrow generation line and a multichannel spectrum analyzer based on diffraction a spectrograph and time-gated ICCD camera. The sensitivity of the system is evaluated for a detection range of 10 m. A detection limit is attained for the traces of nitrogen-containing chemical materials with a surface density of 0.5 μg/cm2 at a signal accumulation of over 1000 laser pulses.

Integrated Photonic Chip Enabled Simultaneous Multichannel Wideband Radio Frequency Spectrum Analyzer

Radio frequency (RF) spectrum analysis is an essential technique for monitoring signal quality in ultrahigh-speed optical transmission, broad bandwidth photonic RF arbitrary waveform generation, and for characterization of high repetition rate optical pulse sources. Whereas the intrinsic bandwidth of electronics limits its use for RF spectrum measurement of high-speed signals, a photonic approach based on ultrafast Kerr nonlinear effects can readily measure the RF spectrum of optical signals having a bandwidth beyond 1 THz. The majority of fiber-based or integrated photonic RF spectrum analyzers reported to date can monitor only one channel at a time. We demonstrate how to harness mode-selective excitation of nonlinear optical effects to perform simultaneous multichannel RF spectrum analysis using a single integrated silicon photonic device. This approach, which can be scaled to a higher number of channels, opens up a new degree of freedom for realizing multichannel signal characterization using a single integrated photonic device.

New Applications of a Three-Phase Arc and a MAES Analyzerfor Spectral Analysis of Rocks

The results of using a multi-channel analyzer of emission spectra (MAES) and “Atom” software for multielement atomic-emission spectral analysis ofrocks using spill-injection method are presented. Replacing of the visual interpretation of spectra by high-quality digital processing significantly in creases the performance of the analysis, extendes the range of detectable concentrations, and improves the metrological characteristics of determination of micro and macro components of rocks.

Statistical Analysis of Sea Surface Temperature and Chlorophyll-a Concentration Patterns in the Gulf of Tadjourah (Djibouti)

The sea surface temperature (SST) and chlorophyll-a concentration (CHL-a) were analysed in the Gulf of Tadjourah from two set of 8-day composite satellite data, respectively from 2008 to 2012 and from 2005 to 2011. A singular spectrum analysis (SSA) shows that the annual cycle of SST is strong (74.3% of variance) and consists of warming (April-October) and cooling (November-March) of about 2.5C than the long-term average. The semi-annual cycle captures only 14.6% of temperature variance and emphasises the drop of SST during July-August. Similarly, the annual cycle of CHL-a (29.7% of variance) depicts high CHL-a from June to October and low concentration from November to May. In addition, the first spatial empirical orthogonal function (EOF) of SST (93% of variance) shows that the seasonal warming/cooling is in phase across the whole study area but the southeastern part always remaining warmer or cooler. In contrast to the SST, the first EOF of CHL-a (54.1% of variance) indicates the continental shelf in phase opposition with the offshore area in winter during which the CHL-a remains sequestrated in the coastal area particularly in the south-east and in the Ghoubet Al-Kharab Bay. Inversely during summer, higher CHL-a quantities appear in the offshore waters. In order to investigate processes generating these patterns, a multichannel spectrum analysis was applied to a set of oceanic (SST, CHL-a) and atmospheric parameters (wind speed, air temperature and air specific humidity). This analysis shows that the SST is well correlated to the atmospheric parameters at an annual scale. The windowed cross correlation indicates that this correlation is significant only from October to May. During this period, the warming was related to the solar heating of the surface water when the wind is low (April-May and October) while the cooling (November-March) was linked to the strong and cold North-East winds and to convective mixing. The summer drop in SST followed by a peak of CHL-a, seems strongly correlated to the upwelling. The second EOF modes of SST and CHL-a explain respectively 1.3% and 5% of the variance and show an east-west gradient during winter that is reversed during summer. This work showed that the seasonal signals have a wide spatial influence and dominate the variability of the SST and CHL-a while the east-west gradient are specific for the Gulf of Tadjourah and seem induced by the local wind modulated by the topography.

Experimental Evaluation of the UV Raman Lidar Sensitivity in Detection of Traces of Chemical Compounds

Experimental results are presented on the remote detection of traces of some chemical compounds on the surface with the help of Raman lidar built on the basis of an excimer KrF laser with a narrow line emission and multi-channel spectrum analyzer based on the diffraction spectrograph and a time gated ICCD camera. The sensitivity of the system is evaluated for the sensing range of 10 m. At the accumulation of the signal over 1000 laser pulses, the detection threshold of the nitrogencontaining chemical compounds of about of units of μg/cm2 has been reached. The effect of the substrate material on the sensitivity of the Ramanlidar method for detecting traces of chemicals on the surface is analyzed.

Spectral Analysis of Hair to Determine the Elemental Status of Human

The article presents the data on development of methods for spectral analysis of human biological substrates in order to determine and restore its elemental balance. The developed method of mass concentration measurement of elements in human biological substrates (hair) by the method of arc atomic emission spectrometry using multichannel analyzer of emission spectra has been submitted for inclusion in the Federal register of RF techniques. By this technique we examined the concentration of macro- and microelements in the hair of 63 patients with ischemic stroke accompanied by depressive disorders (group 1) and post-stroke cognitive impairment (group 2) received in the order of emergency medical care in hospitals. There has been determined the increase of the upper limits of physiological norm of Co, Cd and Al in comparison with the reference values for both groups. In the second group of patients significantly higher content of Cr, Fe, Cd, Pb, Cu, Mn is observed. It is shown the necessity of introduction of new treatment protocols for stroke patients, including macro - and micronutrients to start pharmacological correction treatment as soon as possible.

On certain features of spectrum recording and photometric measurements of spectral lines using a MFS-MAES-based digital spectrograph

Features of recording spectra and performing photometric measurements of spectral lines using a digital spectrograph, which is based on an MFS-8 setup with a MAES multichannel emission spectrum analyzer (photodiode array assembly), are studied. Possibilities of optimizing the analytical signal and time parameters of the spectrum exposure for extending the linear range of the calibration curve and increasing the concentration sensitivities both in areas of low and high contents of determined elements by the atomicemission spectral analysis are shown.

Automated multichannel broadband spectrum analysis of fibre-optic grating sensors

In this paper, we report methods for spectrum analysis and data processing algorithms. An automated multi–channel spectrum measurement system is introduced with controlled fibre–optic signal switching and spectrum analysis with linear CCD photodiode array, diffraction grating and precise stepper motor. The designed system demands advanced measurement and data processing techniques. This paper reports the implemented methods for automated multi–channel measurements, accuracy improvement, noise cancellation techniques and fibre–optic grating sensor measurements.