Fluorimetric Determination of Some Sulfur Containing Compounds Through Complex Formation with Terbium (Tb<Superscript>+3</Superscript>) and Uranium (U<Superscript>+3</Superscript>)

Two simple, sensitive and specific fluorimetric methods have been developed for the determination of some sulphur containing compounds namely, Acetylcysteine (Ac), Carbocisteine (Cc) and Thioctic acid (Th) using terbium Tb⁺³ and uranium U⁺³ ions as fluorescent probes. The proposed methods involve the formation of a ternary complex with Tb⁺³ in presence of Tris-buffer method (I) and a binary complex with aqueous uranyl acetate solution method (II). The fluorescence quenching of Tb⁺³ at 510, 488 and 540 nm (λ_ex 250, 241 and 268 nm) and of uranyl acetate at 512 nm (λ_ex 240 nm) due to the complex formation was quantitatively measured for Ac, Cc and Th, respectively. The reaction conditions and the fluorescence spectral properties of the complexes have been investigated. Under the described conditions, the proposed methods were applicable over the concentration range (0.2–2.5 μg ml⁻¹), (1–4 μg ml⁻¹) and (0.5–3.5 μg ml⁻¹) with mean percentage recoveries 99.74±0.36, 99.70±0.52 and 99.43±0.23 for method (I) and (0.5–6 μg ml⁻¹), (0.5–5 μg ml⁻¹), and (1–6 μg ml⁻¹) with mean percentage recoveries 99.38±0.20, 99.82±0.28 and 99.93±0.32 for method (II), for the three cited drugs, respectively. The proposed methods were successfully applied for the determination of the studied compounds in bulk powders and in pharmaceutical formulations, as well as in presence of their related substances. The results obtained were found to be in agree statistically with those obtained by official and reported ones. The two methods were validated according to USP guidelines and also assessed by applying the standard addition technique.     

A Simple and Sensitive Spectrofluorimetric Method for Analysis of Some Nitrofuran Drugs in Pharmaceutical Preparations

A simple, rapid, selective and sensitive spectrofluorimetric method was described for the analysis of three nitrofuran drugs, namely, nifuroxazide (NX), nitrofurantoin (NT) and nitrofurazone (NZ). The method involved the alkaline hydrolysis of the studied drugs by warming with 0.1 M sodium hydroxide solution then dilution with distilled water for NX or 2-propanol for NT and NZ. The formed fluorophores were measured at 465 nm (λ _Ex 265 nm), 458 nm (λ _Ex 245 nm) and 445 nm (λ _Ex 245 nm) for NX, NT and NZ, respectively. The reaction pathway was discussed and the structures of the fluorescent products were proposed. The different experimental parameters were studied and optimized. Regression analysis showed good correlation between fluorescence intensity and concentration over the ranges 0.08–1.00, 0.02–0.24 and 0.004–0.050 μg ml⁻¹ for NX, NT and NZ, respectively. The limits of detection of the method were 8.0, 1.9 and 0.3 ng ml⁻¹ for NX, NT and NZ, respectively. The proposed method was validated in terms of accuracy, precision and specificity, and it was successfully applied for the assay of the three nitrofurans in their different dosage forms. No interference was observed from common pharmaceutical adjuvants. The results were favorably compared with those obtained by reference spectrophotometric methods.     

Spectrofluorimetric Determination of Oxamniquine in Dosage Forms and Spiked Human Plasma through Derivatization with 1-dimethylaminonaphthalene-5-sulphonyl chloride

A sensitive, simple and selective spectrofluorimetric method was developed for the determination of oxamniquine (OXM) in pharmaceutical formulations and biological fluids. The method is based on the reaction between the drug and 1-dimethylaminonaphthalene-5-sulphonyl chloride (dansyl chloride) in presence of 0.5 M sodium carbonate (pH 10) to yield a highly fluorescent derivative that is measured at 445 nm after excitation at 335 nm. The different experimental parameters affecting the development and stability of the reaction product were carefully studied and optimized. The fluorescence concentration plot was rectilinear over the range of 0.02–0.2 μg ml⁻¹ with a lower detection limit (LOD) of 0.007 μg ml⁻¹ and limit of quantitation (LOQ) of 0.02 μg ml⁻¹. The proposed method was successfully applied to the analysis of commercial capsules. The results obtained were in good agreement with those obtained using the official spectrophotometric method. Furthermore, the method was applied for the determination of oxamniquine in spiked human plasma, the mean % recovery (n = 4) is 97.77 ± 1.19. A proposal of the reaction pathway was presented.     

Resonance Rayleigh Scattering,Second-Order Scattering and Frequency Doubling Scattering Spectra of Copper(II)-Flutamide System with Anionic Surfactants and its Analytical Application

A simple, sensitive, and rapid method based on ion association, for the determination of FLD has been developed. Flutamide (FLD) can react with Cu(II) to form 1:1 cationic chelate at pH 2.2–7.0 Mclivaine buffer medium, which can further react with anionic surfactants (AS) such as sodium dodecyl sulfate (SDS), sodium lauryl sulfonate (SLS) and sodium dodecylbenzene sulfonate (SDBS) to form 1:1 ion-association complexes. As a result, the resonance Rayleigh scattering (RRS), second-order scattering (SOS) and frequency doubling scattering (FDS) were enhanced to the highest degree. The maximum RRS, SOS and FDS wavelengths of three ion-association complexes were located at 345/345 nm, 610/305 nm and 430/860 nm, respectively. The increments of scattering intensity (ΔI) were directly proportional to the concentration of FLD in certain ranges. The detection limits (3σ) of FLD for SDS, SLS and SDBS systems were 1.9 ng ml⁻¹, 2.1 ng ml⁻¹ and 2.2 ng ml⁻¹(RRS method), 2.4 ng ml⁻¹, 2.7 ng ml⁻¹ and 2.6 ng ml⁻¹ (SOS method) and 2.3 ng ml⁻¹, 2.4 ng ml⁻¹ and 2.5 ng ml⁻¹ (FDS method), separately. The sensitivity of RRS method was higher than those of FDS and SOS methods. The optimum conditions of RRS method and the influence factors, the composition and the reaction mechanism have been discussed. Since the method is highly selective, it does not interference concomitant substances. These methods were applied successfully for the determination of FLD in pharmaceutical formulation and urine samples.     

Simultaneous Determination of Acetylsalicylic Acid and Caffeine in Pharmaceutical Formulation by First Derivative Synchronous Fluorimetric Method

A sensitive, rapid, and specific assay has been developed for the simultaneous determination of acetylsalicylic acid and caffeine in commercial tablets based on their natural fluorescence. The mixture of these drugs was resolved by first derivative synchronous fluorimetric technique using two scans. At Δλ=106 nm, using first derivative synchronous scanning, only acetylsalicylic acid yields a detectable signal at 316 nm (peak to zero method) which is unaffected by caffeine. At Δλ=30 nm, the signal of caffeine at 288 nm (peak to zero method) is not affected by acetylsalicylic acid. The range of application is between 0.021 and 41.62 μg ml⁻¹ (correlation coefficient, R=0.9995) for acetylsalicylic acid and between 0.4486 and 44.86 μg ml⁻¹ (correlation coefficient, R=0.99786) for caffeine. The recovery range of 98.40–102% for acetylsalicylic acid and 90–100.5% for caffeine from their synthetic mixture was reported. Overall recovery of both compounds about 97–99% for acetylsalicylic acid and 97–98% for caffeine was obtained from real sample analysis. The detection limits are 0.0013 μg ml⁻¹ and 0.0306 μg ml⁻¹ for acetylsalicylic acid and caffeine, respectively. The relative standard deviation (n=10) for 20 μg ml⁻¹ of acetylsalicylic acid is 2.75% and for 2.2 μg ml⁻¹of caffeine is 1.7%.     

Generation of coherent tunable deep UV radiation for detection and absorption studies of explosives RDX and TNT

We report a technique for the efficient generation of tunable coherent deep UV radiation and its application in studies of RDX and TNT at the ppm level on the basis of their absorption characteristics. The obtained experimental absorption data are compared with conventional spectrophotometric data. The UV radiation in the range 200–260 nm has been generated by the type-I noncollinear third harmonic of the dye laser radiation (600–700 nm) and also by sum frequency mixing (SFM) of Nd:YAG output (1064 nm) with the second harmonic of the dye laser in β-barium borate (BBO) crystal. The maximum conversion efficiency of the generated signal is estimated to be 57.5% at λ = 218.9 nm wavelength. Apart from measurements of the absorbance of RDX and TNT at different concentrations in their respective solutions, the minimum detection concentrations have also been ascertained. The estimated minimum detectable concentration of RDX is 8.47·10⁻⁹ M, whereas that for TNT is 35.7·10⁻⁹ M. The data were obtained using only ∼100 μJ/pulse of laser energy. Published in Zhurnal Prikladnoi Spektroskopii, Vol. 74, No. 6, pp. 516–521, July–August, 2007.     

New fluorimetric reagents, sodium pyrophosphate, sodium trimetaphosphate, and sodium tetrametaphosphate, for the determination of cerium(III)

Three sensitive and selective new alternatives for fluorometric determination of cerium(III) are described in this study. Ce(III) is highly fluorescent in sodium pyrophosphate, sodium trimetaphosphate, and sodium tetrametaphosphate solutions. For these reagents, the maximum excitation/emission wavelengths are 300/350, 297/340, and 299/352 nm, respectively. Maximum fluorescence intensities are obtained by irradiating Ce(III) dissolved in 0.033 g L⁻¹ sodium pyrophosphate, 41.4 g L⁻¹ sodium trimetaphosphate, and 0.96 g L⁻¹ sodium tetrametaphosphate at room temperature. The fluorescence intensities are linear over the range 0.001–30, 0.001–75, and 0.001–70 μg ml⁻¹. The detection limits are calculated as 9.5 × 10⁻³, 1.1/10⁻³, and 3.8 × 10^-3 μg ml⁻¹ Ce(III), respectively. The relative standard deviations for 15/0.05 Μg ml⁻¹ Ce(III) are 1.1/1.2, 1/1.1, and 1.2/1.3%, respectively. Quenching effects of other lanthanides and some inorganic anions were investigated. The methods have been applied to rare earth mixtures with a good accuracy.     

Preparation and Characterization of CdHgTe Nanoparticles and Their Application on the Determination of Proteins

CdHgTe nanoparticles (NPs) with the emission in the near-infrared regions were prepared in aqueous solution, and were characterized by transmission electron microscopy, X-ray diffraction spectrometry, spectrofluorometry and ultraviolet-visible spectrometry. Based on the fluorescence quenching of CdHgTe NPs in the presence of proteins, a novel method for the determination of proteins with CdHgTe NPs as a near-infrared fluorescence probe was developed. Maximum fluorescence quenching was observed with the excitation and emission wavelengths of 500 and 693 nm, respectively. Under the optimal conditions, the calibration graphs were linear in the range of 0.04 × 10⁻⁶–5.6 × 10⁻⁶ g ml⁻¹ for lysozyme (Lyz) and 0.06 × 10⁻⁶–6.1 × 10⁻⁶ g ml⁻¹ for bovine hemoglobin (BHb), respectively. The limits of detection were 13 ng ml⁻¹ for Lyz and 27 ng ml⁻¹ for BHb, respectively. Four synthetic samples were determined and the results were satisfied.     

RAYLEIGH LIGHT SCATTERING ENHANCING REACTION OF DIBROMOCHLOROARSENAZO AND PROTEINS SYSTEM AND ITS ANALYTICAL APPLICATION

Based on the enhancement effects of Rayleigh light scattering (RLS) on Arsenazo-DBC, a novel quantitative method for the determination of proteins in aqueous solutions has been proposed. The reaction of Dibromochloroarsenazo (Arsenazo-DBC) and five proteins (BSA, HSA, egg albumin, human γ-IgG, Lysozyme) has been studied. Under optimal conditions the dynamic ranges for proteins were 2.5–60.0 μg·ml^?1, and the detection limits for HSA and BSA were at 98.50 ng·ml^?1 and 88.10 ng·ml^?1, respectively. Comparing with other methods, the method is simple, practical and relatively free from interference from coexisting substances. The method was employed for the determination of total protein in human serum with satisfactory results.     

Determination of Trace Mercury by Solid Substrate-Room Temperature Phosphorimetry Quenching Method Based on Catalytic Effect of Hg2+on Formation of the Ion Association Complex [Sn(XO)6]4+·[(Fin)4]

A new method for the determination of trace mercury by solid substrate-room temperature phosphorimetry (SS-RTP) quenching method has been established. In glycine-HCl buffer solution, xylenol orange (XO) can react with Sn⁴⁺ to form the complex [Sn(XO)₆]⁴⁺. [Sn(XO)₆]⁴⁺ can interact with Fin⁻ (fluorescein anion) to form the ion associate [Sn(XO)₆]⁴⁺·[(Fin)₄]⁻, which can emit strong and stable room temperature phosphorescence (RTP) on polyamide membrane (PAM). Hg²⁺ can catalyze H₂O₂ oxidizing the ion association complex [Sn(XO)₆]⁴⁺·[(Fin)₄]⁻, which causes the RTP to quench. The ΔIp value is directly proportional to the concentration of Hg²⁺ in the range of 0.016–1.6 fg spot⁻¹ (corresponding concentration: 0.040–4.0 pg ml⁻¹, 0.40 μl spot⁻¹), and the regression equation of working cure is ΔIp=10.03+83.15 m Hg²⁺ (fg spot⁻¹), (r=0.9987, n=6) and the detection limit (LD) is 3.6 ag spot⁻¹(corresponding concentration: 9.0×10^–15 g ml⁻¹, the sample volume: 0.4 μl). This simple, rapid, accurate method is of high selectivity and good repeatability, and it has been successfully applied to the determination of trace mercury in real samples. The reaction mechanism for catalyzing H₂O₂ oxidizing the ion association complex ([Sn(XO)₆]⁴⁺·[(Fin)₄]⁻) SS-RTP quenching method to determine trace mercury is also discussed.     

Validated Spectrofluorimetric Method for the Determination of Lamotrigine in Tablets and Human Plasma Through Derivatization with <Emphasis Type="BoldItalic">o</Emphasis>-phthalaldehyde

A sensitive, simple and selective spectrofluorimetric method was developed for the determination of Lamotrigine (LMT) in pharmaceutical formulations and biological fluids. The method is based on reaction of LMT with o-phthalaldehyde in presence of 2-mercaptoethanol in borate buffer of pH 9.8 to yield a highly fluorescent derivative that is measured at 448 nm after excitation at 337 nm. The different experimental parameters affecting the development and stability of the reaction product were carefully studied and optimized. The fluorescence-concentration plot was rectilinear over the range of 0.1–1.0 μg ml⁻¹ with lower limit of detection (LOD) 0.02 μg ml⁻¹ and limit of quantification (LOQ) 0.06 μg ml⁻¹ respectively. The proposed method was successfully applied to the the analysis of commercial tablets. Statistical comparison of the results obtained by the proposed and reference method revealed no significant difference in the performance of the two methods regarding the accuracy and precision respectively. The proposed method was further extended to the in-vitro and in-vivo determination of the drug in spiked and real human plasma. The mean percentage recoveries in spiked and real human plasma (n = 3) were 95.78 ± 1.37 and 90.93 ± 2.34 respectively. Interference arising from co-administered drugs was also studied. A proposal for the reaction pathway with o-phthalaldehyde was postulated.     

Application of 3-methylbenzothiazolin-2-one hydrazone for the quantitative spectrophotometric determination of oxcarbazepine in pharmaceuticals with cerium(IV) and periodate

Two simple, sensitive, selective, accurate, and cost-effective spectrophotometric methods are described for the assay of oxcarbazepine (OXC) in bulk drug and in tablets. The methods are based on an oxidative coupling reaction involving OXC, 3-methylbenzothiazolin-2-one hydrazone (MBTH), and cerium(IV) sulfate at pH 4.28 ± 0.07 (method A) or sodium periodate at pH > 4.0 (method B) to form an orange colored product with an absorption maximum at 450 nm. Under optimized experimental conditions, the calibration graphs are linear over the ranges of 4–80 and 2–32 μg/ml for methods A and B, respectively, with correlation coefficient (r) values of 0.9984 and 0.9976. The apparent molar absorptivity values are 3.13⋅10³ and 9.13⋅10³ l/mol⋅cm for methods A and B, respectively. The other optical characteristics such as Sandell’s sensitivity, limits of detection (LOD) and quantification (LOQ) values are also reported. The accuracy and precision of the methods were evaluated based on intra-day and inter-day variations. The proposed methods were successfully applied to the determination of OXC in tablets: the results were comparable with the published data obtained using the reference method. The reaction stoichiometry of OXC with MBTH (1:1 in method A and 1:2 in method B) was also evaluated using the limiting logarithmic method, and a possible reaction pathway is presented for the both methods.     

Spectrofluorimetric Determination of Fluvoxamine in Dosage Forms and Plasma Via Derivatization with 4-Chloro-7-Nitrobenzo-2-Oxa-1,3-Diazole

A highly sensitive and simple spectrofluorimetric method has been developed and validated for the determination of the antidepressant fluvoxamine (FXM) in its dosage forms and plasma. The method was based on nucleophilic substitution reaction of FXM with 4-chloro-7-nitrobenzo-2-oxa-1,3-diazole in an alkaline medium (pH 8) to form a highly fluorescent derivative that was measured at 535 nm after excitation at 470 nm. The factors affecting the reaction was carefully studied and optimized. The kinetics of the reaction was investigated, and the reaction mechanism was presented. Under the optimized conditions, linear relationship with good correlation coefficient (0.9995) was found between the fluorescence intensity and FXM concentration in the range of 65–800 ng ml⁻¹. The limits of detection and quantitation for the method were 21 and 64 ng ml⁻¹, respectively. The precision of the method was satisfactory; the values of relative standard deviations did not exceed 2.17%. The proposed method was successfully applied to the determination of FXM in its pharmaceutical tablets with good accuracy; the recovery values were 97.8–101.4 ± 1.08–2.75%. The results obtained by the proposed method were comparable with those obtained by the official method. The high sensitivity of the method allowed its successful application to the analysis of FXM in spiked human plasma. The proposed method is superior to the previously reported spectrofluorimetric method for determination of FXM in terms of its simplicity. The proposed method is practical and valuable for its routine application in quality control and clinical laboratories for analysis of FXM.     

Solid Substrate–Room Temperature Phosphorimetry for the Determination of Trace Terbutaline Sulfate Based on Its Inhibition Oxidation of Rhodamine 6G by Sodium Periodate

When 1.00 mol l⁻¹ I⁻ is used as ion perturber, rhodamine 6G (Rh 6G) can emit strong and stable room temperature phosphorescence (RTP) on filter paper substrate in KHC₈H₄O₄–HCl buffer solution (pH = 3.50), heated at 70 °C for 10 min. NaIO₄ can oxidize Rh 6G, which makes the RTP signal quench. Terbutaline sulfate (TBS) can inhibit NaIO₄ from oxidizing Rh 6G, which makes the RTP signal of Rh 6G enhance sharply. The content of TBS is linear correlation to ΔIp of the system. Based on the facts above, a new inhibition solid substrate-room temperature phosphorimetry (SS-RTP) for the determination of trace TBS has been established. The linear range of this method is 0.0104–2.08 pg spot⁻¹ (corresponding concentration: 0.026–5.2 ng ml⁻¹, with a sample volume of 0.4 μl) with a detection limit (L.D.) of 2.6 fg spot⁻¹ (corresponding concentration: 6.5 × 10⁻¹² g ml⁻¹), and the regression equation of working curve is ΔIp = 2.040 + 54.54 m_TBS (pg spot⁻¹), n = 6, correlation coefficient is 0.9994. For the samples containing 0.0104 pg spot⁻¹ and 2.08 pg spot⁻¹ TBS, the relative standard deviation (RSD) are 3.8% and 2.3% (n = 8), respectively, indicating good precision. This method has been applied to determination of trace TBS in the practical samples with satisfactory results. The reaction mechanism of NaIO₄ oxidizing Rh 6G to inhibit SS-RTP for the determination of trace TBS is also discussed.     

Sensitive Spectrofluorimetric Determination of Cytochrome c with Spirocyclic Rhodamine B Hydrazide in Micellar Medium

A new spectrofluorimetric method for the determination of cytochrome c using spirocyclic rhodamine B hydrazide (RBH) as fluorogenic reagent in the presence of sodium dodecylbenzene sulfonate (SDBS) surfactant micelles was developed. The method was based on the reaction of cytochrome c with RBH, a colorless, nonfluorescent spirolactam of rhodamine B in SDBS micelles to give highly fluorescent rhodamine B and hence led to a large increase in fluorescence intensity. The dynamic range and detection limit for the determination of cytochrome c are 4.0–120 ng ml⁻¹ and 0.87 ng ml⁻¹ (3σ), respectively. The optimal conditions for the detection of cytochrome c were evaluated and the possible detection mechanism was also discussed.     

Validated spectrophotometric method for the determination,spectroscopic characterization and thermal structural analysis of duloxetine with 1,2-naphthoquinone-4-sulphonate

A novel, selective, sensitive and simple spectrophotometric method was developed and validated for the determination of the antidepressant duloxetine hydrochloride in pharmaceutical preparation. The method was based on the reaction of duloxetine hydrochloride with 1,2-naphthoquinone-4-sulphonate (NQS) in alkaline media to yield orange colored product. The formation of this complex was also confirmed by UV-visible, FTIR, ¹H NMR, Mass spectra techniques and thermal analysis. This method was validated for various parameters according to ICH guidelines. Beer’s law is obeyed in a range of 5.0–60 μg/mL at the maximum absorption wavelength of 480 nm. The detection limit is 0.99 μg/mL and the recovery rate is in a range of 98.10–99.57%. The proposed methods was validated and applied to the determination of duloxetine hydrochloride in pharmaceutical preparation. The results were statistically analyzed and compared to those of a reference UV spectrophotometric method.     

Flow Injection Spectrofluorimetric Determination of Iron in Industrial Effluents based on Fluorescence Quenching of 1-Naphthol-2- Sulfonate

A sensitive and selective spectrofluorimetric method has been developed for flow injection analysis (FIA) of iron(III) based on its fluorescence quenching effect on the water soluble 1-naphthol-2-sulfonate. The fluorescence emission spectra were collected with excitation at 283 nm. The emission peaks of the neutral and anionic forms of 1-naphthol-2-sulfonate as well as the band area were found to decrease linearly with iron(III) concentrations over the range 0.1–18 μg ml⁻¹ and a detection limit of 3.4 ng ml⁻¹ (emission at 349 nm) with FIA. Possible interferences from different cations and anions, which could affect the analytical response, are evaluated and showed the high selectivity of the method. The effect of solution pH and 1-naphthol-2-sulfonate concentration were examined and the reaction conditions are optimized. The method is successfully applied to determine iron(III) in industrial effluents from different sources without any complications with recoveries of almost 100% with both manual and flow injection methods. Results were found to be very consistent with those obtained using atomic absorption spectrometry.     

A Simple Flow-injection Spectrofluorimetric Method for the Determination of Mercury

A highly sensitive flow-injection spectrofluorimetric method is presented for the rapid and simple determination of Hg (II) in environmental and pharmaceutical samples. Murexide (ammonium purpurate) was used as the fluorescence reagent in the carrier stream. An emission peak of murexide, which is decreased linearly by addition of Hg (II), occurs at 435 nm in aqueous solution with excitation at 335 nm. A linear calibration was obtained for 5–200 ng ml⁻¹ Hg (II) with the relative standard deviation 2.5% (n = 5) for a 20 μl injection volume Hg (II). The limit of the detection was 1 ng ml⁻¹ and the sampling rate was 80 h⁻¹. No significant interference was found by the ions commonly found in the most environmental samples. The proposed method was successfully applied for the determination of trace mercury in real samples and the validation of the proposed methodology is provided.     

Spectrophotometric and Spectrofluorimetric Determination of Certain Diuretics Through Ternary Complex Formation with Eosin and Lead (II)

Simple and sensitive spectrophotometric and spectrofluorimetric methods have been developed for the determination of hydrochlorothiazide (I), indapamide (II) and xipamide(III) based on ternary complex formation with eosin and lead (II) in the presence of methylcellulose as surfactant. The methods do not involve solvent extraction. For spectrophotometric method, the ternary complex showed an absorption maximum at 543 nm. The factors affecting the formation of ternary complex were studied and optimized. The method obeys Beer’s law over concentration range of 8–40 μg mL⁻¹. A fluorescence quenching method for the determination of the cited drugs by forming this ternary complex was also investigated for the purpose of enhancing the sensitivity of the determination. The analytical performance of both methods was fully validated, and the results were satisfactory. The methods have been successfully applied for the determination of the studied drugs in their pharmaceutical tablets and the results obtained ware in good agreement with those obtained by the reference method. Common excipients used as additives in tablets do not interfere with the proposed methods.     

The dynamics of accumulation of electrically active radiation defects on implantation of graded-band-gap HgCdTe films grown by MBE

The dynamics of accumulation of electrically active radiation defects under ion doping of epitaxial Cd _x Hg _1−x Te films is studied for various distributions of film composition in the implantation region. The epitaxial films were irradiated by boron ions at room temperature in the continuous regime, with the dose ranging within 10¹¹−3·10¹⁵ cm⁻², energy — 20–150 keV, and ion current density — j = 0.001–0.2 μA·cm⁻². It is found that the natural logarithm of the introduction rate of electrically active radiation defects linearly depends on the epitaxial-film composition in the range of mean projected path of implanted ions. An analysis of the experimental data shows that the dynamics of accumulation of electrically active radiation defects is determined by the epitaxial-film composition in the implantation region. __________ Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 9, pp. 25–28, September, 2006.