Electrochemical methods and analysis of their role in the protection of the nautical medium. Portable electrochemical analyzers Thank you for your respect
Elektrohіmіchnі Methods Analizu - Tsuupnіst Methods of the Yakіsnaya І Kilkіsnya Analiza, Scho Vіdbuyuyu in the village of Dzhuvani Hellovisii Aboy on Cordoni Ridge Phase І Rov'jaki Zi Zmіnu Structuri, Himіchnaya Skala Abo concentrations of analis-free speech.
Electrochemical methods of analysis (ex) are based on processes, proceed on electrodes or in the interelectrode space. Їx advantage is high accuracy and equal simplicity of both equipment and methods of analysis. The high accuracy is determined by the very precise regularities of vikoristovuvanimi in Yehman. The great success is those who, in this method, use an electric infusion, and those who, as a result of this infusion (vіdguk), can also come out at the sight of an electric signal. This ensures a high level of speed and precision, and opens wide possibilities for automation. Ekhman is distinguished by garnoy sensitivity and selectivity, in a number of ways it can be taken to microanalysis, so for analysis it is sometimes possible to take less than 1 ml of rozchiniv.
According to the different types of the analytical signal, it is subdivided into:
1) conductometry - vimir elektroprovіdnostі doslіdzhuvannogo razchin;
2) potentiometry - vimir bezstrumovo equal to the potential of the indicator electrode, for which the speech is potentiated;
3) coulometry - the reduction of the amount of electrical energy, necessary for the re-transformation (oxidation or reduction) of the final speech;
4) voltammetry - vimir of stationary and non-stationary polarization characteristics of electrodes in reactions for the participation of pre-sliding speech;
5) electrogravimetry - vimir mass of speech, seen from a variety in electrolysis.
27. Potentiometric method.
Potentiometer - vimir bezstrumovo ї equal to the important potential of the indicator electrode, for which dosledzhuvan speech є potentiodetermining.
A) standard (electrode povnyannya) - may have a permanent potential, so you can’t lie in the air. minds
B) individual electrode - yogo potential to deposit depending on the concentration of speech.
Potential to deposit in terms of concentration: Е = f (c)
Rivnyannia Nerista Е = Е ° + lna kat
E° - standard. Electron. potential (const)
R- univer. gas supplyconst)
T - absolute pace (t)- +273 °
.p - number of electrons involved. At oxide. / Restore reactions
. a - active concentration
potentiometry method
Onometry potentiometry (before the research. The solution is small. In portions, the standard solution (titran) is added, after the skin addition the potential is reduced - E)
point of equivalence
EСх Vх = l t * Vt
28. Conductometric method.
conductometriya- vimir elektroprovіdnostі doslіdzhuvannogo rozchin.
Conductometric titration
Conductivity meter (attachment)
Conductometric analysis (conductometry) of foundations on vicarious fallows between electrical conductivity (electrical conductivity) of differences in electrolytes and their concentration.
About the electrical conductivity of the differences in electrolytes - conductors of a different kind - to judge on the basis of the vimiryuvannia of the electrical support in the electrochemical center, yak represents a glass vessel (flask) with two soldered in a new electrode, between yakami and Through the center pass a light electric jet. Electrodes are most often made from metal platinum, for the sake of increasing the surface of the electrodes they are covered with a ball of spongy platinum with a path of electrochemical precipitation from platinum alloys (electrodes with platinum-plated platinum).
29. Polarography.
Polarography is a method of acidic and acidic chemical analysis, bases on the original curves of the fallow of the magnitude of the struma and the voltage in the lances, it is composed of the last difference and zanurennye of the new electrodes, one of them is strongly polarized, and the other is practically non-polarizing. Otrimanya such curves - polarogram - slacken for the help of polarographs.
The polarographic method is characterized by great sensitivity. For vikonannya analysis, call for 3-5 ml of the required amount. Analysis for the help of an auto-registering polarograph takes about 10 minutes in total. Polyarografії Vicarious for a visnant in Ok'єktsa bіologico-hiking by ZM_TSti Rutchyniy Rechovyn (RTUTHY, Scholuk Merratі, Swinzyu, Taliu I and In.), For a visit to the dick of blood by Kronovo, Dzlіzzhenna Warehouse Rutter, Scho seeing, Shkіdlivich Rechovin in the Podtrіvіt analysis may have great sensitivity and give the ability to detect speech at an insignificant (up to 0.0001%) concentration in retail.
30. Classification of spectral methods for analysis. Understanding the spectrum.
Spectral analysis - the sequence of methods for determining the quality of the quantity. Warehouse, as well as the very structure of speech (based on the interdependence of the research object with different types of speech production.)
All spectroscopic methods are based on the interplay of atoms, molecules or ions, which enter the warehouse of the analyzed speech, with electromagnetic vibrance. Tsya vzaimodiya is manifested in the clayed or emitted photons (quanta). Depending on the nature of the interaction between the sample and the electromagnetic vibration, two groups of methods are seen -
Emision and absorption. Due to the fact that the analytical signal is often formed, the methods of atomic spectroscopy and the methods of molecular spectroscopy are distinguished
emisiyna
In emis_ynih methods, the analyzed sample as a result of її zbudzhennya viprominyuє photon.
absorption
In absorption methods, vibrating a third-party dzherel is passed through a sample, in which part of the quanta is vibrated by atoms or molecules
range- deciphered the value of a physical quantity (sound energy, frequency or mass). A graphic representation of such a distribution is called a spectral diagram. Sound under the spectrum is affected by the electromagnetic spectrum - the frequency spectrum (or the same as the energy of the quants) of the electromagnetic vibration.
1.reflection of light
2. turn of the beam of light (defraction)
3. light scattering: nephelometry, turbidimetry
4.light absorption
5 re-emission
A) phosphorescence (three days)
B) fluorescence (albeit short)
According to the nature of the distribution, the value of the physical magnitude of the spectrum can be discrete (linear), continuous (successive), and also represent a combination (overlay) of discrete and continuous spectra.
Mass spectra and spectra of bonded-linked electronic transitions of the atom can serve as examples of line spectra; the butts of non-permanent spectra - the spectrum of electromagnetic vibration of a heated solid body and the spectrum of free-willed electronic transitions of the atom; The butts of combined spectra are the spectra of vibrating stars, where chromospheric lines of clay or more sound spectra are superimposed on the superspheric spectrum of the photosphere.
31. Photometry: the principle of the method, zastosuvannya in court.іsledovaniyakh.
Photometry - a spectral method of foundations on the clay of the electromagnetic vibration of the visible and near ultraviolet range (the method of foundations on the clay of the light)
molecular Atomic
Spectroscopy spectroscopy (In electron.Analysis)
Ditch - pass light through it
l
I (intensity of light output)
I ° - intensity of the incident light.
Photometry - a division of physical optics and imaging techniques, assignments to methods for investigating the energy characteristics of optical vibrance in the process of emission, expansion in different media and interaction with bodies. Photometry is carried out in the ranges of infrared (dovzhini hvil - 10 -3, ... 7 10 -7 m), visible (7 10 -7, ... 4 10 -7 m) and ultraviolet (4 10 -7 ... 10 -8 m) optical viprominyuvan. With the widening of the electromagnetic variation of the optical range in the biological medium, a number of main effects are observed: claying and expansion of the distribution of atoms and molecules of the medium, expansion of the medium inhomogeneities on the particles, depolarization of the production Registry data in relation to the optical viability with the medium, you can determine a number of parameters related to the medical and biological characteristics of the object. For vimiryuvannya photometric values zastosovuyut prilad - photometry. From the point of view of photometry, light - tse viprominyuvannya, zdatne vyklikaty vіdchutya brilliance when spitting on the human eye. At the basis of photometry as a science lies A. Gershuni's theory of the light field.
There are two main methods of photometry: 1) visual photometry, in which, when mechanical or optical methods are used to visualize the radiance of two waterings, the quality of the human eye is observed in the radiance; 2) physical photometry, in order to match two dzherel lights, different types of lights of a different kind are used - vacuum photocells, photodiode heaters, etc.
32. The law of Bouguer-Lambert-Beer, yogo quotation in calisthenics analysis.
The physical law that signifies the weakening of a parallel monochromatic beam of light with the expansion of light in the clay center.
The law is expressed by the offensive formula:
,
de intensity of the incoming beam, - tovshchina to the ball of speech, through which it is light to pass, - Pokaznik poglanannya (do not stray with the infinite pokaznik poglanyannya, some kind of po'azaniya formulas, here dozhina hvili).
Pokaznik pokalinannya characterizes the power of the speech and fall in the old days of the wind, λ svetla svetla. Tsya staleness is called the spectrum of the slurry of speech.
For the opening of clay speeches in non-absorbing light-filled containers, an indication of the claying can be recorded as
de - coefficient that characterizes the interaction of the clay molecule of the dispersed speech with light and long quill λ, -concentration of the dissolved speech, mol / l.
The firmness that does not lie in water is called Beer's law (do not stray with Beer's law). This is the law of transmission, so that it is not light to pour into the building of the clay molecule other distinct molecules of speech and speech in different. However, one should beware of numerical compliance with the law, especially with the great ones.
Jacgsho through the actant ball Retaching Abo Gas to Tovshchino (passing Svitloviy Potіk іntensnіsti I, then for the law of Lamberta - Bera Kilkіt Pontown Svіtla Buda Proportoiniyino, Scho Pieoto Svіtlo, i Tovshchini Schu) Law BMB, IKTLY , which falls on the speech and the past yogo, with the concentration of the speech and the tovshchina of the clay ball Yake lightly dries under the singing vіdsotkom. Tobto surplus in the exit of light є
33.IR spectroscopy.
The purpose of this method is to analyze the bases on the recording of infrared spectra of the slurry of speech. Poglinannya rechovina in the area of infrachervonogo viprominyuvanya vіdbuvayutsya for rahunok so kolivanie atoms in molecules. The ringing is carried out on the valence (if in the course of the ringing they change in the course of the ringing between atoms) and the ringing (if in the course of the ringing the rings are changed between the links). Go between different staves in quantization molecules, why zavdyanya in the ІЧ-region may change the shape of the spectrum, de kozhny kolyvannyu in іdpovidaє its own dozhina whilі. It dawned on me that it’s not enough to lie down for dermal kolivany in order to take a fate in the new, and moreover, it’s not enough to lie down in the form of sharpening.
The method of IF-spectroscopy is not divided by the method, so that in the case of a certain speech, it can be shown that the sum of a dozen speeches is truly summed up, which greatly contributes to the results of deciphering the spectrum. Well, it’s still not entirely correct to talk about the unambiguous identification of speech for the help of the IC-spectroscopy method, since the method allows you to reveal the same functional groups, and not their number in one and the same way.
The method of IF-spectroscopy is victorious in the course of investigations of polymeric materials, fibers, lacofarb coatings, narcotic drugs (when identified, they often act as carbohydrates, including polysaccharides). The method is especially indispensable in the case of advanced oiling materials, since it gives the possibility of one-hour determination of nature as the basis of the oiling material, as well as possible additives (additives) to the strength of the base.
34. X-ray fluorescence analysis.
(XRF) is one of the modern spectroscopic methods for investigating speech with a method of omitting the elemental warehouse, that is, the elemental analysis. For help, they can analyze different elements from beryllium (Be) to uranium (U). The method of X-ray diffraction analysis of the foundations for the selection of a long-term analysis of the spectrum, taken with a vein on the follow-up material to x-ray vibrance. When the atom is passed, the atom goes into an excitation camp, which goes into the transition of electrons to a higher energy level. At the awakened station, the atom is rested for a very small hour, about one microsecond, after which it turns in a calm position (the main camp). With this electron from the outer shells, either the vacant spaces have disappeared, and too much energy is lost at the visible photon, or the energy is transferred to the other electron from the outer shells (Auger electron)
Ecology and protection of the natural environment: the importance of important metals in soils, litter, water, aerosols and in.
Geology and mineralogy: yakіsny і kіlkіsny analysis of gruntіv, mineralіv, gіrskіh porіd i іn.
Metallurgy and chemical industry: quality control of syrovine, manufacturing process and finished products
Lakofarb's industry: analysis of lead farb
35. Atomic emission spectroscopy.
Atomic emission spectral analysis is a set of methods of elemental analysis based on the production of spectra of the release of free atoms and ions from the gas phase. Record emission spectra in the most transparent optical region at a wavelength of 200 to 1000 nm.
AES (Atomic Emission Spectrometry) - a method for determining the elemental composition of speech according to optical spectra of vibrating atoms and ions in an analyzed sample, which are destroyed in the flasks of light. Yak dzherela light for atomic emission analysis see different plasma, including electric spark or arc plasma, laser spark plasma, inductively coupled plasma, fluorescent discharge and in. AES is the most extensive express highly sensitive method for identifying the most important elements of houses in gas-like, rare and hard cavities, including high-purity ones.
Areas of congestion:
Metallurgy: analysis of the stock of metals and alloys,
Girnichodobouvna craftsmanship: research of geological sights and mineral syrovina,
Ecology: analysis of water and soil,
Technique: analysis of motor oils and in. Tekhnіchnyh rіdin on metal houses,
Biological and medical research.
Principle dії.
The principle of operation of an atomic emission spectrometer is simple. There are grounds for the fact that the atoms of the skin element can viprominuate the light-singing lengths of the wind - spectral lines, moreover, the number of the lengths of the wind is different for different elements. In order for the atoms to begin to be lightened, it is necessary to destroy them - by heating, by an electric discharge, by a laser, or in some other way. The more atoms of this element are present in the analyzed eye, the better will be the improvement of the future sickness.
The intensity of the spectral line of the analyzed element, the concentration of the analyzed element, to deposit due to a large number of different factors. Because of this reason, it is impossible to theoretically loosen the link between the intensity of the line and the concentration of the viable element. The axis of why for the analysis of the necessary standard samples, close behind the warehouse to the analyzed sample. In front of the standard eyes are displayed (disappeared) on the prilad. Following the results of the treatment for the skin analyzed element, there will be a graduation of the graph, so that the intensity of the spectral line intensity of the element depends on its concentration. Every year, at the hour of the analysis of samples, for these graduation schedules, a re-run of the measured intensities in concentrations is carried out.
Preparation of samples for analysis.
Follow the mother on the uvazi, scho really analysis is given a little milligram sample from її surfaces. Therefore, in order to obtain the correct results, the sample must be identical to the warehouse and structure, while the warehouse of the sample must be identical to the warehouse of the analyzed metal. When analyzing metal in a liquor or smelter, it is recommended to use special molds to infuse samples. With this, the form of the sample can be sufficient. It is more necessary to analyze the surface with enough space and momentarily squeeze it in a tripod. For the analysis of other sights, for example, rods or rods, you can use special adapters.
Advantages of the method:
non-contact,
Possibility of a one-hour celebration of a great number of elements,
high precision,
Low mezhі vyavlennya,
Ease of sample preparation
Low sociability.
36. Atomic absorption spectroscopy.
the method of quantity determination of the elemental warehouse of the finished speech by the atomic spectra of clay, based on the density of atoms in vibirk clay of electromagnet viprominium in decomp. spectrum plots. A.-a.a. carry out on a special attachment - absorption. spectrophotometers. The sample of the analyzed material is divided (especially with the solutions of salts); rozchin at the sight of an aerosol is served in half an ointment. Under half-moon (3000 ° C), the molecules of salts dissociate into atoms, which can turn bright. Then, through the half-light, the burners pass a beam of light, in the spectrum of a large and similar to the other element of the spectral line. From a global perspective, the resulting spectral lines are seen with a monochromator, and the intensity is fixed with a registration block. Mat. processing is carried out according to the formula: J = J0 * e-kvI,
de J і J0, - intensity of the past and incident light; kv - coefficient poglinannya, scho to lie in its frequency; I - tovshchina of a clay ball
more sensitive lower AES
37. Nephelometry and turbidimetry.
S = lg (I ° / I) In solution (I °) divisible by the intensity of the exit from the difference (I) \u003d
k-const
b - dozhina way beam of light
N-number of chastok in one. r-ra
In nephelometric and turbidimetric analyses, there is a manifestation of the emergence of light by solid particles, which are found in difference in the advanced state.
Nephelometry is a method of determining the dispersion and concentration of column systems for the intensity of the light scattered by them. Nephelometriya, vimiryuvannya carried out in a special device nephelometriya, vrazhayuchi dії yakikh osnovanі on porіvnіnіnі іtensії rozsіyannogo doslіdzhuvanії svetla s іntensivnosti svіtla, rosіany іnshim іnshіmi scho serve as standard. Teorіya rozsіyuvannya Svitla koloїdnimi systems, yakih rozmіri chastok not perevischuyut dovzhini napіvhvilі padayuchogo Svitla, Bula rozroblena anglіyskim fіzikom J. Rayleigh in 1871. Zgіdno іz law Rayleigh іntensivnіst Svitla I, rozsіyanogo in napryamku perpendicular to padayuchogo Promen, virazhaєtsya formula I = QNvlk - de q - intensity of the incident light, N - total number of particles per unit volume, or partial concentration, v - total of one particle, \ - length of the incident light, k - constant dispersive medium, in the presence of light, as well as in those taken alone
Turbidimetry is a method for the analysis of calamity mediums, bases on the vimiryuvannі intensity of the light clayed by them. Turbodimetric measurement is carried out in the light for additional turbidimetry of visual or photoelectric colorimeters. The technique of vimiryuvan is similar to the colorimetric one and it is grounded on the stagnation to the calamity mediums of Bouguer-Lambert - Beer's law, which in times of suspension is fair only for narrower thin balls or for significant dilutions. With turbidimetry, it is necessary to trim the amount of light to illuminate the dispersed phase, which is similar to the amount of time required for nephelometry. Significantly improved turbidimetry is used in the turbidimetric titration to the maximum turbidity for the help of photoelectric colorimeters. Turbidimetry is successfully victorious for the analytical designation of sulphates, phosphates, chlorides, cyanides, lead, zinc and others.
The main advantage of the nephelometric and turbidimetric methods is their high sensitivity, which is especially valuable in relation to the elements or ions, for any daily color reactions. In practice, it is widely zastosovuetsya, for example, nephelometrically assigned to chloride and sulfate in natural waters and similar objects. For the accuracy of turbidimetry and nephelometry, photometric methods are acquitted, which is attributed to the main rank, with difficulties in removing suspensions, which allow the same sizes of particles, stability in hours, etc. insufficient reproducibility of chemical and analytical powers of suspensions.
Nephelometry and turbidimetry stop, for example. between the appointed values \u200b\u200b~ 0.1 μg / ml. To standardize the minds of analysis in experiments, it is necessary to strictly control the temperature, the total suspension, the concentration of reagents, the speed of mixing, the hour of the experiment. The settling may run smoothly, but the parts of the guilty mother are small in size and low in size. To prevent coagulation of the great chasts, a stabilizer is often added to the solution, for example. gelatin, glycerin.
38. Chromatography: history of vindication, principle to method, litigation. Follow-up.
Chromatography is a dynamic sorption method for the separation and analysis of the sums of speeches, as well as the development of the physical and chemical power of speeches. Foundations on the distribution of speeches between two phases - non-destructive (solid phase of aboridine, tied on an inert nose) and loose (gas abortive phase, eluent). Calling the method associated with the first experiments on chromatography, in the course of which the Mikhailo Kolir method was developed, he clearly captured the growing pigments.
The method of chromatography was first developed by the Russian botanist Mikhail Semyonovich Kolor in 1900. Vіn vikoristovuvav column, filled with calcium carbonate, for the bottom of the pigment dewdrop. The first information about the development of the chromatography method was broken by Kolor on December 30, 1901 on XI Z'їzdі naturalists and doctors in St. Petersburg. The first work on chromatography was published in 1903, in the journal Practices of the Warsaw Association of Doslidnik_v prirody. first term chromatography appearing in two other robots of Colori in 1906, published in a German journal Berichte der Deutschen Botanischen Gesellschaft. In 1907, Rotis Kolir demonstrates his method To the German Botanical Society.
In 1910-1930, the rocky method was undeservedly neglected and practically did not develop.
In 1931, R. Kuhn, A. Winterstein and E. Lederer, using additional chromatography, saw α and β fractions of gray carotene in a crystalline appearance, and demonstrated the preparative value of the method.
In 1941, A. J. P. Martin and R. L. M. Sing developed a new variety of chromatography, which was based on the combination of subdivisions of mixed speeches between two immiscible natives in the coefficients. Method by removing the name " rozpodіlna chromatography».
In 1947, T. B. Gapon, E. N. Gapon, and F. M. Shemyakin developed the method of “ion-exchange chromatography”.
In 1952, J. Martin and R. Sing were awarded the Nobel Prize in Chemistry for their work on the method of differential chromatography.
From the middle of the 20th century to the present day, chromatography has been intensively developed and has become one of the most widely used analytical methods.
Classification: Gazova, Ridinna
Fundamentals of chromatography. process. For carrying out chromatographic podіlu v-in or designation of їх fіz.-khіm. characteristics ring vikoristovuyut spec. attach - chromatography. Main nodes of the chromatograph - chromatographic. column, detector, as well as attachments for introducing samples. The column, as a way to avenge the sorbent, vikonuє f-tsіyu dividing the analyzed sums on warehouse components, and the detector - f-tsіyu їkh kіlkost. appointment. The detector, rotting at the exit from the column, automatically and without interruption indicates the concentration of the injected compounds. in the flow of ruhomo After the introduction of the analyzed sum with the flow of the ruhomo phase into the column of the zone of all in - in the chromatographic cob. columns (Fig. 1). Under the flow of the dry phase, the components of the sumish begin to move around the column s decomp. the values, the values of which were taken, were wrapped in proportion to the coefficients subdivided to the chromatographed component. Good sorption capacity, the value of the distribution constants for those took great, shifting the ball of the sorbent over the column more, lower porosity sorption capacity. Therefore, component A should leave the column more quickly, then component B and the rest fill the column with component C (K A<К Б <К В). Сигнал детектора, величина к-рого пропорциональна концентрации определяемого в-ва в потоке элюента, автоматически непрерывно записывается и регистрируется (напр., на диаграммной ленте). Полученная хроматограмма отражает расположение хроматографич. зон на слое сорбента или в потоке подвижной фазы во времени.
Mal. one. Submitted the sum of three components (A, B and C) on the chromatographic column To with detector D: a - the position of the chromatographic zones of the added components in the column through the sing of hour intervals; b - chromatogram (C - signal, t - hour) .
With flat layer chromatography. put the arkush paper or the plate with the ball of the sorbent with the applied samples of the final content is placed in the chromatographic. camera. After the subdivision of the component, it is determined whether it is an appropriate method.
39. Classification of chromatographic methods.
Chromotography - a method of separation and analysis of speeches, foundations on roses By-va between 2 phases: ruhomoyu and indestructible
Razchin sumishi rechovina pіdlyagayut rozpodіlu, pass through a glass tube (adsorption column) filled with adsorbent. As a result, the components of the sum are utrimuyutsya at different heights of the adsorbent at the same time around the zones (balls). Things adsorb more quickly. Nah in the upper part of the stovp, and more adsorbed in the lower part of the stovp. To be adsorbed late - to pass through the column without zatrimuyuchi and get into the filter.
classification:
1. According to the aggregate phase phase.
1) Rukhoma
A) gas (inert gases: helium, argon, azon)
B) native
2. according to the method of conducting
1) on a plane (planar); paper thin layer
2) column
A) packed (packed column filled with sorbent)
B) capillary (thin glass / quartz capillary on the inner surface of which a non-rubber phase is applied)
Can you def. Items in small quantities.
Flying in-va podіlyayutsya.
40. Chromatogram. Main parameters of the chromatographic peak.
The chromatogram is the result of the registration of the concentration of the components at the exit from the column per hour.
H S
The skin peak on the chromatogram is characterized by two basic parameters
1. Hour of morning ( t R) - the same hour from the moment of introduction of the sample, which is analyzed until the moment of registration to the maximum of the chromatographic peak. Vono to lie in the nature of speech and є yakіsnoy characteristic.
2. Visota ( h) Abo area ( S) pik
S = ½ ω × h. (4)
The height and area of the peak lie in the quantity of speech and its characteristics.
The hour of priming is added up from two warehouses - the hour of rebuking speeches in a ruhomy phase ( t m) I hour of rebuking in a non-volatile phase ( t s):
Identification of peaks of unknown components in the analyzed sum is to be carried out by way of ordering (pairing) to be carried out. values, yakі vynachayutsya without intermediary s chromatograms, s vіdpovіdnimi tabular data for vіdomih spoluk. When identified in chromatography, reliable only negative. confirmation; e.g., pik i is not є in vom A, so the hours of priming pіku i і v-va A are not avoided. Zbіg hrsіv utrimuvannya piku i і in-va A - is necessary, but there is not enough mind for laying, scho peak i - tse in-in A.
At praktichnіy robotі vibіr addition chi іnshogo parameter for kіlkіsnoї rozshifrovki chromatograms viznachaєtsya sukupnim vplivom dekіlkoh faktorіv shvidkіstyu i zruchnіstyu rozrahunku, formyl (br, vuzky) i stage asimetrії hromatografіchnogo pіku, efektivnіstyu vikoristovuvanoї column povnotoyu podіlu Components Connection sumіshі, nayavnіstyu neobhіdnih avtomatizovanih pristroїv (іntegratorіv, computer systems for data processing of chromatographic analysis).
The parameter of the chromatographic peak is manually adjusted by the operator on the chromatogram after the cycle is completed under the component in the analyzed sum
The parameter of the chromatographic peak is automatically controlled by the help of digital voltmeters, integrators or special EOMs at once with the lowest component in the analyzed sum in the column and by recording by chromatograms
Oskіlki tehnіka rozshifrovki chromatograms zvoditsya to vimіryuvannya parametrіv chromatographic pіkіv tsіkavit i standard z'єdnan, minds hromatografuvannya povinnі zabezpechuvati by mozhlivostі Povny їh podіl INSHI skladovі vihіdnoї OOO All samples in priynyatih minds analіzu mozhut not vіdokremlyuvatisya one od one abo navіt vzagalі not proyavlyatisya on hromatogramі (in Why should the internal standard method prevail over the internal normalization method)
41. Qualitative chromatographic analysis.
With a sufficient length of the column, it is possible to expand the separation of the components, no matter how crazy. And after separating the separation of the components in the okremі fraction (Eluat) determine the number of components in the sum (it depends on the number of eluates), establish their oxiological warehouse, determine the quantity of the dermal part of them, and become the most important method of analysis.
Yakіsny chromatograph of the Analizi, Tobto Іntekіfіkatsіyu Rechovini on a yogo chromatogram mozda vico vinevniyuyvnymnia chromatographic characteristics, nipsystіshit to exercise Fazyuha (Tobto Flasy Floying, skipped through the column of Vіdchka introduced Sumyshi to the appendix of the Damn Component on the Vodiki column), validation analyzed the sum and for the purpose.
42. Quantitative chromatographic analysis.
A chromatographic analysis should be carried out on a chromatograph. The method of foundation on the basis of varying parameters of the chromatographic peak, which should lie in the concentration of the chromatographed speech - height, width, area and heightened obyagu, or create a heightened obyagu on the height of the peak.
In the country's gas chromatography, there are methods of absolute calibration and internal normalization, or normalization. Vykoristovuєtsya also the method of internal standard. With absolute grading, experimentally determine the fallowness of the height or the area of the peak in the concentration of the speech and graduating graphs will be used, or the rank of the coefficients will be determined. Then, the same characteristics of the peaks in the analyzed sum are determined, and according to the graduation graph, the concentration of the analyzed speech is known. This simple and accurate method is the main one for the diagnosis of microdomestic shocks.
When using the internal normalization method, the sum of any parameters in the peaks, for example, the sum of the heights of all peaks or the sum of their areas, is taken as 100%. Either changing the height of the peak to the sum of the heights, or changing the area of one peak to the sum of the area when multiplied by 100 will characterize the mass fraction (%) of the component in the sum. With this approach, it is necessary that the value of the value of the measured parameter in terms of concentration is the same for all components of the sum.
43. Planar chromatography. Vykoristannya tonkosharova chromatography for the analysis of ink.
The first form of victorious cellulose in thin sphere chromatography was paper chromatography. Available plates for TSHH and highly productive TSHH allow the separation of the sum of the polar rivers, with which, in the quality of the eluent, at least, the losses of the sum of the water, do not mix with it the organic grower and the water grower, but spray the adopted one
Here DU2 is the difference in potentials between chloride and hydrochloric acid at a concentration of chloride in
acids 0.1 mol / l, DU20 - potential difference between sable chloride and hydrochloric acid at
concentration of chloride in acid 1 mol / l (standard), R, T and F - generally universal gas
constant, absolute temperature and Faraday number. Oskіlki doyucha concentration of chloride in
in chloride it was stable in nature, and in hydrochloric acid it was stable due to the fact that the tube is closed and not
to exchange the speech with the serene expanse, to mean permanently and їх vіdnoshennia and the logarithm of the vіdnosiny:
DU2 = const.
Only one component of the lancet is left behind in succession of the last electrochemical elements DU3.
Price difference of potentials on glass membranes. The material of the membrane is chosen in such a way that
they hardly pass water and do not pass other ions.
Numerical experimental studies have shown that the difference in potential varies
equals:
DU3 = (RT / F) ln (son / [H +] in hydrochloric acid) (8)
Suvoro theory for explaining this fact is not used until the present time, although it is necessary
explanation.
Logarithm of the average cost of logarithms:
DU3 = (RT / F) ln (cal) - (RT / F) ln [H +] in hydrochloric acid) (9)
Another addendum in the right part of the river (9) cannot be deposited in the warehouse of the old ration, so we can
make yogo a constant.
20.
At a wild slope, as if the homeland is part of an electric stake, then get outfor singing minds like an electric opir, conductivity G
which is distinguished by viraz
Electrochemical methods of analysis are based on the variation of potentials, the strength of the strum and other characteristics in the interplay of the analyzed speech with an electric strum.
Electrochemical methods are divided into three groups:
¨ methods based on electrode reactions that flow in the presence of the struma (potentiometry);
¨ methods based on electrode reactions that flow under a deep struma (voltammetry, coulometry, electrogravimetry);
¨ methods based on vimirs without the passage of an electrode reaction (conductometry - low-frequency titration and oscillometry - high-frequency titration).
According to the acceptance of the application of electrochemical methods, they are classified into straight, Based on the non-intermediate occurrence of the analytical signal in terms of the concentration of speech, and indirectly(Installation of equivalence point during titration).
For registration of an analytical signal, two electrodes are required - an indicator and a signal. Electrode, the potential of which to deposit in the form of activity is determined by ions, is called indicator. Vіn is guilty of swidko and reversely reacting to the change in concentration of ions in rozchinі. The electrode, the potential of which cannot be deposited in the form of activity, is characterized by ions and is permanently depleted, is called electrode.
potentiometer
Potentiometric method foundations on the vimiryuvanni elektrorukhomy forces of reverse galvanic elements and zastosovuetsya to determine the concentration of ions in retail.
The method of breaking apart in the last century, after that, since in 1889 Walter Nernst viviv rivnyannia, which links the potential of the electrode with the activity (concentration of speeches):
de - standard electrode potential, V; 0.059 - constant, which includes universal gas constant (), absolute temperature and Faraday constant (); - the number of electrons that take part in the electrode reaction; і - activity of oxidized and derived forms of speech, apparently.
When zanurenny metal plates in the gaps, on the cordon of the metal gaps, equal
Me 0 ↔ Me n + + nē
and vinikaє elektrodny potential. It is not possible to undermine this potential, but it is possible to undermine the electro-destructive power of a galvanic cell.
The additional galvanic element is made up of two electrodes, which can be wired in one and the same size (element without transfer) or in two different sizes outside the warehouse, which can be a common contact (lance with transferred).
Electrode, the potential of which to deposit in the form of activity is determined by ions, is called indicator: E \u003d f (c). Electrode, the potential of which cannot be deposited due to the concentration of ions and is permanently called electrode. Yogo stop for vimiryuvannya potential of the indicator electrode.