31. Applications of the chromatographic methods in drug analysis

Transcription

1 31. Applications of the chromatographic methods in drug analysis Depending on the processes that underlie the chromatographic separation, the following methods exist: A. adsorption chromatography B. partition chromatography C. absorption chromatography D. steric exclusion chromatography E. ion exchange chromatography The common elements of the chromatographic methods are: A. the presence of a stationary phase and a mobile phase B. the two phases are immiscible C. between the quantity of the analytes distributed between the two phases there is no equilibrium D. the migration of the analytes along the stationary phase is carried out at different speeds E. the separation consists of continuous elution of the analytes leaving the column successively *The chromatographic Rf is: A. a measure which depends on the nature of the carrier gas B. the ratio b/a; a = the migration distance of the sample; b = the migration distance of the mobile phase front C. the ratio a/b; a = the migration distance of the mobile phase front; b = the migration distance of the sample D. a measure that depends on the retention time and volume E. the ratio a/b; a = the migration distance of the sample; b = the migration distance of the mobile phase front Which of the following statements are true about the supercritical fluid chromatography: A. is used for the separation of thermolabile substances B. is a complementary method for gas and liquid phase chromatography C. is a complementary method for exclusion-diffusion chromatography D. capillary columns can be used as in gas chromatography E. columns filled with ion exchange resins can be used The detection of the analyte spots in TLC can be performed through the following processes: A. examining the spectra libraries B. the examination of the chromatographic plates in UV C. exposing the chromatographic plates to iodine vapors D. measuring the peaks on the chromatogram E. spraying the plates with various reagents * The following chromatographic methods are officialized by the RP X th edition, except: A. paper chromatography B. thin layer chromatography C. gas chromatography D. pressure liquid chromatography (high performance/pressure liquid chromatography HPLC) E. ion exchange chromatography According to RP X th edition, revealing the spots on the chromatogram (in TLC) is performed as follows: A. examination as such in visible light B. examination in visible light after spraying with appropriate reagents C. measuring the chromatographic peak D. examination under UV light at 366 nm E. examination under UV light at 254 nm

2 Which of the following statements are true regarding the resolution of the separation process in chromatography: A. expresses the ability of the chromatographic system to separate the components of a mixture B. depends on the distance between the tops of the peaks C. depends on the width of each of the two peaks D. the lower its value is, the better the resolution E. is the ratio of the distance traveled by the analyte and the distance traveled by the mobile phase front The dextran gels used as supports in size exclusion chromatography have the following characteristics: A. are obtained from dextran through a crosslinking reaction with the epichlorohydrin of glycerol in a basic medium B. contain galactose molecules C. are also called Sephadex D. have a good mechanical rigidity E. are obtained by the polymerization of acrylamide with a cross-linking agent If we consider a reversible ion exchange reaction between two ions A and B, the following statements are true, except: A. if the resin has a higher affinity for the ion B than for the ion A, the value of the equilibrium constant is greater than the unit, K A/B >1 B. if the resin has a higher affinity for the ion B than for the ion A, the value of the equilibrium constant is smaller than the unit, K A/B <1 C. the value of the equilibrium constant is greater as the difference between the affinities for ions A and B is greater D. the value of the equilibrium constant is greater as the difference between the affinities for ions A and B is smaller E. the value of the equilibrium constant is smaller as the difference between the affinities for ions A and B is greater The scheme of a gas chromatograph contains the following components: A. carrier gas tank B. injector C. chromatographic column D. monochromator E. detector * The determination of the separated components using GC may be achieved by the following processes but one: A. area normalization method B. internal standard method C. calibration curve method D. UV examination method E. external standard method Gas chromatography: A. is a chromatographic method of separation B. uses a gas as a mobile phase C. uses a liquid as a stationary phase D. uses a liquid as a mobile phase E. uses a solid as a stationary phase

3 In gas chromatography, programming the temperature by gradually increasing it, determines the: A. obtaining of a good separation through the acceleration of the chromatographic processes B. obtaining of wide peaks C. increase the concentration of the substances in the gaseous mobile phase D. increase of the distribution coefficient E. obtaining of narrower peaks, with smaller base In high performance liquid chromatography: A. the stationary phase is a fine-grained solid B. the stationary phase is a solid impregnated with a liquid C. the mobile phase is a liquid D. the mobile phase is a gas E. the stationary phase is a gel In which of the following chromatographic methods, the two phases, the mobile and stationary phases are not liquid: A. partition chromatography, bound normal or reverse phase B. exclusion chromatography through polar separations C. partition chromatography with adsorbed normal or reverse phase D. exclusion chromatography through non polar separations E. ion exchange chromatography with chelating resins * The following stationary phases are used in size exclusion chromatography, except: A. dextran gel B. silica gel C. sepharose D. polyacrylamide gel E. aerogel In paper chromatography, the stationary phase support has the following characteristics: A. is chromatographic paper B. is made up of cellulose chains C. is hydrophobic D. between the cellulose chains there are a large number of covalent bonds E. can be impregnated alumina, ion exchangers, kieselgur Which of the following statements are true about the retention measures in the chromatographic processes: A. characterizes the analyte retention on the chromatographic column, i.e. on the stationary phase B. the retention time is equal to the volume of mobile phase required to carry an analyte with its maximum concentration in the detector C. the retention ratio is the ratio between the average travel speed of the analyte and the average flow speed of the mobile phase D. comprise retention time, retention volume, retention ratio, retention factor E. the retention factor is the ratio between the amount of analyte that is in the mobile phase and the amount of analyte that is in the stationary phase

4 In the HPLC analysis, the following detectors can be used: A. UV, Vis, IR detectors B. flame ionization detectors C. fluorescence detectors D. mass spectrometry detectors E. refractometric detectors Ion exchange chromatography: A. is a liquid chromatographic technique B. the column is filled with a polymeric stationary phase on which ionizable acidic groups have been grafted C. the column is filled with a polymeric stationary phase on which ionizable basic groups have been grafted D. the stationary phases consist of gels E. the mobile phase consists of non-aqueous solutions The most important characteristics of the chromatographic detectors are: A. specificity B. sensibility C. limit of detection D. liniarity E. the height of the theoretical plate Size exclusion chromatography includes the following techniques, with the exception of: A. gel filtration, in cases where the mobile phase is aqueous B. adsorption to the surface of the stationary phase C. gel permeation, in cases where the mobile phase is organic D. ion exchange E. exclusion size Size exclusion chromatography is used for the: A. separation of polymers or macromolecules with high molecular mass B. separation of molecules of different sizes C. determination of the molecular mass distribution D. determination of the transmittance E. quantitative determination of volatile substances The Van Deemter equation connects the following parameters: A. longitudinal diffusion B. wavelenght C. turbulent diffusion D. absorbance E. the height of the theoretical plate 32. Volumetric methods used in drug analysis In order for a substance to be used as a reference substance it must: A. have a well-defined composition B. be soluble in the chosen solvent, so that to obtain unstable solutions C. be stable D. have a high degree of purity E. not be soluble in the chosen solvent

5 32. 2.* The molarity factor for the volumetric solutions prepared with reference substances, is: A B C D E * According to RP X th edition, for determining the molarity factor of the hydrochloric acid solution 0.1 mol/l, the following reference substance is used: A. sodium hydroxide B. potassium acetate C. ammonium hydrogen carbonate D. potassium hydrogen carbonate E. potassium hydroxide * According to RP X th edition, for determining the molarity factor of the sodium hydroxide solution 0.1 mol/l, the following reference substance is used: A. hydrochloric acid 100 g/l B. hydrochloric acid 200 g/l C. sulfuric acid 100 g/l D. oxalic acid E. no correct answer According to RP X th edition, the following substances can be determined complexonometrically: A. basic magnesium carbonate B. aluminium sulfate C. sodium bromide D. sodium benzoate E. calcium gluconate The phenylbutazone from the ointment with phenylbutazone can be quantitatively determined: A. after dispersion in alcohol B. after dispersion in water C. by titration with HCl 0.1 mol/l D. in the presence of phenol red indicator E. after dispersion and heating, in an alcohol-ether mixture which is previously neutralized According to RP X th edition, the following substances can be quantitatively determined using disodium EDTA: A. calcium carbonate B. calcium gluconate C. sodium chloride D. calcium chloride E. potassium bromide According to RP X th edition, which of the following substances can t be quantitatively determined using disodium EDTA: A. ammonium bromide B. ammonium chloride C. basic bismuth nitrate

6 D. methenamine E. sodium cefotaxime According to RP X th edition, the molarity factor for the sodium thiosulfate solution 0.01 mol/l is determined using: A. potassium permanganate as reference substance B. bromothymol blue as indicator C. potassium dichromate as reference substance D. phenol red as indicator E. starch as indicator The molarity factor for the volumetric solution of potassium permanganate 0.02 mol/l is determined using (according to RP X th edition): A. hydrochloric acid 0.1 mol/l (R) B. oxalic acid as reference substance C. sulfuric acid 100 g/l (R) D. phenolphthalein as indicator E. methyl orange as indicator The molarity factor for the volumetric solution of sodium nitrite 0.1 mol/l is determined using (according to RP X th edition): A. oxalic acid (R) B. sulfanilic acid (R) C. ammonia 100 g/l (R) D. potassium bromide (R) E. metanil yellow - solution (I) When determining the molarity factor for the volumetric solution of iodine 0.01 mol/l the following reagents are used, except (according to RP X th edition): A. potassium hydrogen phosphate (R) B. arsenic trioxide as reference substance C. sodium hydroxide 1 mol/l D. sodium hydrogen carbonate (R) E. methyl orange as indicator According to RP X th edition, for the quantitative determination of theophylline, the following reagents and indicators are used, except: A. silver nitrate 0.1 mol/l B. phenolphtalein - solution (I) C. sodium hydroxide 0.1 mol/l D. perchloric acid 0.1 mol/l in dioxane E. bromothymol blue - solution (I) According to RP X th edition, for the quantitative determination of potassium iodide, the following reagents and indicators are used, except: A. sodium hydroxide 0.1 mol/l B. phenolphtalein - solution (I) C. hydrochloric acid (R) D. phenol red as indicator (I) E. potassium iodate 0.05 mol/l

7 According to RP X th edition, for the quantitative determination of caffeine, the following reagents are used: A. sulfuric acid 100 g/l B. acetic anhydride (R) C. hydrochloric acid 0.1 mol/l D. perchloric acid 0.1 mol/l in anhydrous acetic acid E. sodium hydroxide 0.1 mol/l According to RP X th edition, for the quantitative determination of sodium benzoate, the following reagents and indicators are used: A. phenolphtalein as indicator B. thymol blue in methanol (I) C. sodium hydroxide 0.1 mol/l D. acetic anhydride (R) E. perchloric acid 0.1 mol/l in dioxane According to RP X th edition, for the quantitative determination of ephedrine hydrochloride, the following reagents and indicators are used, except: A. anhydrous acetic acid (R) B. mercury acetate (II) in anhydrous acetic acid (R) C. metanil yellow in dioxane as indicator D. hydrochloric acid 0.1 mol/l E. phenolphtalein as indicator For the quantitative determination of metronidazole from the suppositories with metronidazole, the following reagents and indicators are used (according to RP X th edition): A. chloroform (R) B. methyl red in chloroform (I) C. phenolphtalein solution (I) D. hydrochloric acid 0.1 mol/l E. perchloric acid 0.1 mol/l in dioxane For the quantitative determination of acetylsalicylic acid in tablets, the following reagents and indicators are used (according to RP X th edition): A. methyl red (I) B. chloroform (R) C. alcohol (R) neutralized to phenolphthalein (I) D. sodium hydroxide 0.1 mol/l E. bromothymol blue (I) For the quantitative determination of procaine hydrochloride in injectable solutions, the following reagents and indicators are used (according to RP X th edition): A. sulfuric acid 100 g/l (R) B. sodium nitrite 0.1 mol/l C. potassium bromide (R) D. methyl red (I) E. tropeolin 00 (I)

8 * For the quantitative determination of acetylsalicylic acid in tablets, the following indicator is used (according to RP X th edition): A. methyl orange - solution (I) B. phenolphthalein - solution (I) C. phenol red - solution (I) D. bromothymol blue - solution (I) E. methyl red - solution (I) According to RP X th edition, which of the following substances are dosed through the acido-basic method in anhydrous media? A. papaverine hydrochloride B. caffeine C. sodium tetraborate D. sodium benzoate E. sodium sulfate In order to determine the concentration of the cobalt standard solution, the following reagents and indicators are used (according to RP X th edition): A. ammonium acetate (R) B. eriochrome black T (I) C. murexide (I) D. perchloric acid 0.05 mol/l in dioxane E. disodium edetate 0.05 mol/l In order to determine the concentration of the iron standard solution, the following reagents and indicators are used (according to RP X th edition): A. hydrochloric acid 100 g/l (R) B. potassium iodide (R) C. murexide (I) D. starch (I) E. sodium thiosulfate 0.1 mol/l In order to determine the concentration of the copper standard solution, the following reagents and indicators are used (according to RP X th edition): A. acetic acid 300 g/l (R) B. phenolphtalein - solution (I) C. potassium iodide (R) D. starch (I) E. sodium thiosulfate 0.1 mol/l 33. UV-Vis absorption spectrophotometric methods used in drug analysis *According to RP X th edition, the visible domain is between: A nm B nm C nm D nm E nm

9 *According to RP X th edition, the UV domain is between: A nm B nm C nm D nm E nm The UV-Vis absorption spectrophotometer contains the following parts: A. radiation source B. monochromator C. chromatographic column D. interferometer E. detector Which of the following statements are not true: A. the absorbance is proportional to the concentration of the analyte B. the Lambert-Beer law applies only for concentrated solutions C. the absorbance is the decimal logarithm of the transmittance D. the absorbance is the decimal logarithm of the ratio between the intensity of the incident light and the intensity of the transmitted light E. the absorbance is proportional to the thickness of the absorbent layer The specific absorbance: A. is the absorbance corresponding to a solution layer with a thickness of 1 cm B. is a constant specific to each substance at a given wavelength C. is the absorbance corresponding to a layer of solution containing 1 mg of substance in 100 ml D. is the absorbance corresponding to a layer of solution containing 1 g of substance in 100 ml E. can be used to calculate the concentration of an analyte The absorption spectra in UV-Vis are obtained by graphical representation on: A. abscissa transmittance, ordinate - wavelenght B. abscissa absorbance, ordinate - wavelenght C. abscissa wavelenght, ordinate absorbance D. abscissa wavelenght, ordinate transmittance E. abscissa wavelenght, ordinate absorbance The radiation source in the Visible domain: A. is a hydrogen lamp B. is a tungsten lamp C. is a deuterium lamp D. provides a radiation beam in the range nm E. provides a radiation beam in the range nm The radiation source in the UV domain: A. is a hydrogen lamp B. is a tungsten lamp C. is a deuterium lamp D. provides a radiation beam in the range nm

10 E. provides a radiation beam in the range nm With respect to the electrons from a molecule that participate or not in the electronic transitions, we distinguish the following types of electrons: A. closed electron shell, in which the electrons are involved in chemical bonds B. σ type electrons C. n type electrons D. electrons that are found in unshared electron pairs in the outer shell of some atoms with small mass E. π type electrons, in double and triple bonds n-π* transitions: A. consists in the transition of an electron from a n nonbonding molecular orbital to a π* antibonding molecular orbital B. it is a high intensity transition C. occurs in unsaturated systems, for example - carbonyl compounds D. it is a low intensity transition E. occurs in the far UV (below 200 nm) d-d* transitions: A. specific for the inorganic compounds involving electrons from d molecular orbitals B. occur in UV domain C. occur in VIS domain D. are accompanied by a low absorptivity E. specific for the carbonylic compounds * The following statements related to σ σ* transitions are true, except one: A. consists in an electron transition from a σ bonding orbital to a σ* antibonding molecular orbital B. occur in far UV C. require much energy D. are strong transitions E. occur in near UV Which of the following statements are true about the n electrons involved in electronic transitions: A. are found as unshared pairs of electrons in the outer shell of the atoms with small mass B. are more strongly attracted to the nuclei of these atoms than the σ electrons C. can be excited with UV-VIS radiations D. can contribute to absorptions in the IR domain E. can not be excited with UV-VIS radiations Which of the following statements are true regarding the electrons involved in electronic transitions: A. the σ electrons are involved in σ covalent bonds B. the σ electrons do not contribute to absorptions in the UV-Vis domain C. the π electrons are involved in simple bonds D. the π electrons can be excited very hard E. the π electrons are responsable for most of the electronic spectra

11 The π π* transitions: A. occur in saturated systems B. occur in systems containing an isolated unsaturated ethylenic double bond C. very intense absorption bands correspond to them D. weak absorption bands correspond to them E. are strong transitions The Lambert-Beer law: A. is the fundamental law of absorption B. applies only for suspensions C. applies to concentrated solutions D. is valid only for diluted solutions E. the absorbance is proportional to the concentration of the analyte Which of the following statements are true: A. the hypsochromic effect consists in moving the absorption bands towards higher wavelengths B. hyperchromic effect consists in increasing the intensity of bands C. bathochromic effect consists in moving the absorption bands towards lower wavelengths D. hypsochromic effect consists in moving the absorption bands towards smaller wavelengths E. hyperchromic effect consists in decreasing the intensity of the bands When choosing the solvents used in the UV-Vis spectroscopy the following rules must be taken into account: A. any solvent can be used B. the solvent must not significantly absorb in the spectral region used for the determination of an analyte C. choosing a suitable solvent is a particular problem D. the interactions between analytes and solvents produce changes in the UV spectrum E. must have the absorption maximum at the same wavelength as the analyte In the UV-Vis spectroscopy, the following detectors can be used: A. flame ionization detector B. photomultiplier C. photodiodes D. thermionic detector E. thermal conductivity detector In UV-Vis domain, the determination of concentration can be performed using the following methods: A. the area normalization method B. using the specific absorbance C. the relative volatility method D. the method of least squares E. the standard addition method

12 The advantages of the derivative spectrometry are: A. provides an accuracy smaller than the zero order spectrometry B. the derivative spectra peaks are more pronounced C. the derivative spectra peaks are better differentiated D. provides an accuracy greater than the zero order spectrometry E. provides a resolution lower than the zero order spectrum The spectra derived from the absorption spectrometry have the following characteristics, except: A. provides a better resolution than the original spectrum B. the resolution increases with the order of the derivative C. the resolution decreases with the order of the derivative D. the derived peak amplitude increases with the order of the derivative E. does not offer a better resolution than the original spectrum * Which of the following statements is not correct regarding the derivative spectrometry: A. is applied in drug analysis and control, biochemical and clinical laboratory analysis B. applies when the spectra of the compounds in the mixture are not sufficiently differentiated C. the first and second order derivative spectra are used mainly in analytical practice D. the third order derivative spectrum is the most widely used in analytical practice E. the derivative spectra peaks are sharper, more differentiated In the derivative spectrometry the third order derivative spectrum has the following characteristics: A. presents 2 maximums, a smaller one and a larger second one B. presents 2 minimums, one of which is more important C. presents 2 maximums corresponding to the two inflection points of the first derivative D. takes account of the maximums and minimums of the next higher order derivative spectrum E. the most significant peak is situated at the same length as the zero-order maximum peak In the derivative spectrometry the first order derivative spectrum has the following characteristics: A. has a maximum corresponding to the inflection point of the ascending part of the zero order spectrum B. has a minimum corresponding to the inflection point of the descending part of the zero order spectrum C. presents 2 smaller maximums D. presents 2 pronounced minimums E. is used in analytical practice