Electrothermal vaporization inductively coupled plasma atomic emission spectrometry determination of gold, palladium, and platinum using chelating resin YPA(4) as both extractant and chemical modifier

A new method for determination of trace gold (Au), palladium (Pd), and platinum (Pt) in environmental and geological samples by electrothermal vaporization (ETV)-inductively coupled plasma atomic emission spectrometry (ICP-AES) with the use of chelating resin YPA₄ as both solid phase extractant and chemical modifier has been developed. The resin loaded with analytes was prepared to slurry and directly introduced into the graphite furnace without any pretreatment. The factors affecting the vaporization behaviors of Au, Pd, and Pt were investigated in detail. It was found that, in the presence of YPA₄, Au and Pd could be quantitatively vaporized at lower vaporization temperature of 1900 °C. Compared with the conventional electrothermal vaporization, the vaporization temperature was decreased by 700 °C, and the detection limits for Au and Pd was decreased by a three-fold. However, a little effect of YPA₄ on the ETV-ICP-AES determination of Pt was found. Under the optimized conditions, the detection limits (3σ) of Au, Pd, and Pt for this method are 75, 60, and 217 pg, respectively; and their relative standard deviations (R.S.D.) are 4.4, 5.6, and 3.7%, respectively (n=9, C=0.2 μg ml⁻¹). The proposed method has been applied to the determination of trace Pd and Pt in sewage sludge, and the results well agreed with the recommended values. In order to further verify the accuracy of the developed method, a GBW07293 certified geological reference material and an auto catalyst NIST SRM 2557 reference material were analyzed, and the determined values coincided with the certified values very well.     

Determination of Pd,Rh, Pt,Au in road dust by electrothermal vaporization inductively coupled plasma mass spectrometry with slurry sampling

Inductively coupled plasma mass spectrometry coupled with ultrasonic slurry sampling electrothermal vaporization (USS-ETV-ICP-MS) has been applied to determine Pd, Rh, Pt and Au in 0.5% m/v slurries of several road dust samples. 2% m/v ammonium pyrrolidine dithiocarbamate (APDC) was used as the modifier to enhance the ion count. The influence of instrument operating conditions, slurry preparation and interferences on the ion count was reported. This method has been applied to the determination of Pd, Rh, Pt and Au in BCR 723 Road Dust and NIST SRM 2709 San Joaquin Soil reference materials and two road dust samples collected locally. The analysis results of the standard reference materials agreed with the certified values. Precision between sample replicates was better than 10% for all the determinations. The method detection limits estimated from standard addition curves were 0.9, 0.4, 0.6 and 0.4 ng g⁻¹ for Pd, Rh, Pt and Au, respectively, in original dust samples.     

Application of low temperature electrothermal vaporization ICP-AES for determination of refractory yttrium with 1-(2-pyridylazo)-2-naphthol as chemical modifier

A low temperature electrothermal vaporization inductively coupled plasma atomic emission spectrometry (ETV-ICP-AES) method was developed for the determination of the refractory yttrium, using 1-(2-pyridylazo)-2-naphthol (PAN) as chemical modifier. The trace yttrium was vaporized as PAN complex into plasma from a graphite furnace at a comparatively low temperature of 1200 °C. The operation conditions were optimized, and the vaporization behavior of Y-PAN chelate and the main factors affecting the determination were investigated in detail. Under the optimized conditions, the detection limit of Y was 0.7 ng ml⁻¹, and the relative standard deviation (R.S.D.) for 0.1 μg ml⁻¹ Y was 4.5% (n=9, v=10 μl). The linear range of calibration curve covered three orders of magnitude. The recommended approach has been applied for analysis of three biological samples with satisfactory results. The accuracy of the method was demonstrated by analyzing two standard reference materials.     

Study on volatilization of ytterbium as 1-(2-pyridylazo)-2-naphthol chelate from electrothermal vaporizer for sample introduction in inductively coupled plasma atomic emission spectrometry

Based on the formation of a volatile 1-(2′-pyridylazo)-2-naphthol (PAN) chelate, a novel method was described for the determination of trace ytterbium by electrothermal vaporization (ETV)-inductively coupled plasma atomic emission spectrometry (ICP-AES). It was found that in the presence of PAN, the trace Yb was quantitatively vaporized from a graphite furnace into ICP at a low temperature of 1100 °C. The main factors affecting the formation and vaporization of the Yb-PAN chelate were investigated in detail. Under the optimized conditions, the 3σ detection limit of Yb for this method was 0.4 ng ml⁻¹ and the relative standard deviation (R.S.D.) for 0.1 μg ml⁻¹ Yb was 3.7% (n=9, v=10 μl). The linear range of calibration spanned three orders of magnitude. The content of Yb in the standard reference material (shrub, GBW 07603) determined by the proposed method was in good agreement with the certified value.     

Simultaneous determination of bromine and chlorine in coal using electrothermal vaporization inductively coupled plasma mass spectrometry and direct solid sample analysis

A new method for the direct analysis of coal using electrothermal vaporization inductively coupled plasma mass spectrometry and direct solid sample analysis was developed, aiming at the determination of Br and Cl. The procedure does not require any significant sample pretreatment and allows simultaneous determination of both elements to be carried out, requiring small mass aliquots of sample (about 0.5 mg). All operating parameters, including carrier gas flow-rate and RF power, were optimized for maximum sensitivity. The use of modifiers/aerosol carriers (Pd, Pd + Al and Pd + Ca) was evaluated, and the mixture of Pd and Ca was chosen, allowing pyrolysis and vaporization temperatures of 700 °C and 1900 °C, respectively. Chlorine was accurately determined using calibration against solid standards, whereas Br could also be determined using calibration against aqueous standard solutions. The limits of quantification were 0.03 μg g⁻¹ for Br and 7 μg g⁻¹ for Cl, and no spectral interferences were observed.     

Monitoring of the exposure to platinum-group elements for two Italian population groups through urine analysis

It is well recognized that automobile catalytic converters are the main source of Pd, Pt and Rh (also called platinum-group elements (PGEs)) in an urban atmosphere. Over recent years, urinary biomonitoring of PGEs has gained considerable importance in assessing the individual human exposure to these elements. This paper reports the concentration ranges of PGEs in the urine of 257 Italian subjects, aged between 23 and 88 years. Subjects were selected on the basis of standardized criteria in two different Italian cities, so as to represent a small urban area surrounded by an essentially rural environment and characterized by low automobile-traffic density (Foligno) and a large urban area with almost constant high-traffic conditions (Rome). The determination of PGEs was performed by sector field inductively coupled plasma-mass spectrometry (SF-ICP-MS) after 1:4 (v/v) dilution of the samples. The 5th and 95th percentiles for PGEs in urine of subjects living in Foligno were the following (in ng l⁻¹): Pd 1.99-17.2, Pt 0.24-3.08 and Rh 0.53-14.8. The 5th and 95th percentiles in the urine of subjects from the area of Rome were (in ng l⁻¹): Pd 0.71-17.0, Pt 0.49-8.13 and Rh 4.10-38.6. Platinum and Rh median concentration values showed large and significant differences (P<0.0001) between the two urban settings considered (0.52 and 3.50 ng l⁻¹ for Pt and Rh in Foligno, respectively, and 1.70 and 12.85 ng l⁻¹ for Pt and Rh in Rome, respectively). On the other hand, no striking differences were found in the Pd concentration (median value of 6.02 ng l⁻¹ in Foligno versus 7.79 ng l⁻¹ in Rome). The sex variable correlates only with Pd concentration (P=0.05), pointing out that in males concentrations are higher than in females.     

Determination of platinum and palladium in road dust after their separation on immobilized fungus by electrothermal atomic absorption spectrometry

A flow solid phase extraction procedure based on biosorption of Pt(IV) and Pd(II) on Aspergillus sp. immobilized on cellulose resin Cellex-T was proposed for the separation and preconcentration of Pt and Pd before their determination by electrothermal atomic absorption spectrometry (ETAAS). The analytical conditions including sample pH, eluent type, flow rates of sample and eluent solutions were examined. The analytes were selectively retained on the biosorbent in acidic medium (pH 1) and subsequently eluted from the column with 1 mL of thiourea solution (0.25 mol L^− 1 thiourea in 0.3 mol L^− 1 HCl). The reproducibility of the procedure was below 5%. The limit of detection of the method was 0.020 ng mL^− 1 for Pt and 0.012 ng mL^− 1 for Pd. The method validation was performed by analysis of certified reference materials BCR-723 (tunnel dust) and SARM-76 (platinum ore). The developed separation procedure was applied to the determination of Pt and Pd in road dust samples by ETAAS.The applied biosorbent is characterized by high sorption capacity: 0.47 mg g^− 1 for Pt and 1.24 mg g^− 1 for Pd.     

Synchronous fluorescence determination of protein with functionalized CdS nanoparticles as a fluorescence probe

Nanometer-sized fluorescent particles have been successfully synthesized. A synchronous fluorescence method, with high sensitivity and selectivity, has been developed for rapid determination of protein with functionalized CdS as a fluorescence probe. When Δλ=260 nm, maximum synchronous fluorescence is produced at 274 nm at pH 7.0. Under optimal conditions, the calibration graphs are linear over the range 0.1-3.0 μg ml⁻¹ for bovine serum albumin (BSA), 0.1-11.0 μg ml⁻¹ for γ-globulin (γ-G) and 0.1-1.4 μg ml⁻¹ for human serum albumin (HSA), respectively. Limits of determination were 0.01 μg ml⁻¹ for BSA, 0.019 μg ml⁻¹ for γ-G and 0.021 μg ml⁻¹ for HSA, respectively. The relative standard deviations of seven replicate measurements were 1.8% for 1.0 μg ml⁻¹ BSA, 2.2% for 1.0 μg ml⁻¹ γ-G and 2.3% for 1.0 μg ml⁻¹ HSA.     

Ultra-trace level determination of hydroquinone in waste photographic solutions by UV-vis spectrophotometry

A simpler UV-vis spectrophotometric method was investigated for hydroquinone (HQ) determination using KMnO₄ as oxidizing agent for conversion of HQ to p-benzoquinone (BQ) as well as signal enhancer. Various parameters such as analytical wavelength, stability time, temperature, pH, solvent effect and interference of chemicals were checked and parameters optimized by using 1 μg ml⁻¹ standard solution of HQ. Beer's Law was applicable in the range of 0.07-2 μg ml⁻¹ and 0.005-0.05 μg ml⁻¹ at 245.5 nm and at 262 nm for aqueous standard solutions of HQ with linear regression coefficient value of 0.9978 and 0.9843 and detection limit of 0.021 μg ml⁻¹ and 0.0016 μg ml⁻¹ HQ, respectively. Standard deviation of 1.7% and 2.4% was true for 1 μg ml⁻¹ and 0.03 μg ml⁻¹ HQ solution (n = 11) run at respective wavelengths. The method was successfully applied to dilute waste photographic developer samples for free HQ determination.     

Development of integrated chemiluminescence flow sensor for the determination of adrenaline and isoprenaline

A novel integrated chemiluminescence (CL) flow sensor for the determination of adrenaline and isoprenaline is developed based on the enhancing effect of analytes on CL emission of luminol oxidized by periodate in alkaline solution. The analytical reagents luminol and periodate are immobilized on anion exchange resins, respectively, and packed in a glass tube to construct a reagentless sensor. The proposed sensor allows the determination of adrenaline and isoprenaline over the range from 2.0×10⁻⁸ to 1.0×10⁻⁵ g ml⁻¹ and 2.0×10⁻⁷ to 5.0×10⁻⁵ g ml⁻¹, respectively. The detection limits are 7.0×10⁻⁹ g ml⁻¹ for adrenaline and 5.0×10⁻⁸ g ml⁻¹ for isoprenaline with a relative standard deviation of 1.7% for the 1.0×10⁻⁷ g ml⁻¹ adrenaline (n=11) and 2.1% for 1.0×10⁻⁶ g ml⁻¹ isoprenaline (n=11). The sample throughput was 60 samples h⁻¹. The sensor has been successfully applied to the determination of adrenaline and isoprenaline in pharmaceutical preparations.     

Determination of palladium in various samples by atomic absorption spectrometry after preconcentration with dimethylglyoxime on silica gel

A preconcentration method based on the adsorption of palladium-dimethylglyoxime (DMG) complex on silica gel for the determination of palladium at trace levels by atomic absorption spectrometry (AAS) has been developed. The retained palladium as Pd(DMG)₂ complex was eluted with 1 mol l⁻¹ HCl in acetone. The effect of some analytical parameters such as pH, amount of reagent and the sample volume on the recovery of palladium was examined in synthetic solutions containing street dust matrix. The influence of some matrix ions on the recovery of palladium was investigated by using the developed method when the elements were present both individually and together. The results showed that 2500 μg ml⁻¹ Na⁺, K⁺, Mg²⁺, Al³⁺ and Fe³⁺; 5000 μg ml⁻¹ Ca²⁺ ; 500 μg ml⁻¹ Pb²⁺; 125 μg ml⁻¹ Zn²⁺; 50 μg ml⁻¹ Cu²⁺ and 25 μg ml⁻¹ Ni²⁺ did not interfere with the palladium signal. At the optimum conditions determined experimentally, the recovery for palladium was found to be 95.3±1.2% at the 95% confidence level. The relative standard deviation and limit of detection (3s/b) of the method were found to be 1.7% and 1.2 μg l⁻¹, respectively. In order to determine the adsorption behaviour of silica gel, the adsorption isotherm of palladium was studied and the binding equilibrium constant and adsorption capacity were calculated to be 0.38 l mg⁻¹ and 4.06 mg g⁻¹, respectively. The determination of palladium in various samples was performed by using both flame AAS and graphite furnace AAS. The proposed method was successfully applied for the determination of palladium in the street dust, anode slime, rock and catalytic converter samples.     

Spectrofluorimetric determination of iridium(IV) traces using 4-pyridone derivatives

A new spectrofluorimetric determination of iridium(IV) with 3-hydroxy-2-methyl-1-phenyl-4-pyridone (HX) or 3-hydroxy-2-methyl-1-(4-tolyl)-4-pyridone (HY) is reported. Iridium(IV) react with HX or HY and chelates were extracted into chloroform or dichloromethane. The organic phase showed fluorescence. The fluorescence measurements to quantify iridium were carried out in its fluorescent band centred at λ_ex=373 nm and λ_em=480 nm. Under optimal conditions, the calibration graphs were linear over the concentration range of 0.1-7.6 μg ml⁻¹ of iridium for Ir(IV)-HX and 0.1-5.8 μg ml⁻¹ for Ir(IV)-HY with a correlation coefficients of 0.999 and 0.992 and relative standard deviation of ±1.1%.The method is free from interference by Rh(III) and Pt(IV), which normally interfere with other methods. Iridium can be determined in the presence of 300-fold excess of rhodium(III) and 10-fold excess of platinum(IV).The method was applied successfully to the determination of iridium in some synthetic mixtures and mineral sample gave satisfactory results.     

Chemiluminescence determination of ultramicro DNA with a flow-injection method

A high sensitive flow-injection chemiluminescence method for determination of calf thymus DNA and herring sperm DNA has been developed. The method is based on the chemiluminescence reaction of Rhodamine B-cerium(IV)-thermally denatured DNAs in sulfuric acid media. The proposed procedure allows quantitation of DNAs in the range 2.6×10⁻⁵ to 0.26 μg ml⁻¹ for calf thymus DNA and 5.0×10⁻⁸ to 5.0×10⁻⁵ μg ml⁻¹ for herring sperm DNA with correlation coefficients 0.9998 and 0.9996 (both n=11), respectively. The detection limits (3σ) are 6.5×10⁻⁶ μg ml⁻¹ for calf thymus DNA and 4.3×10⁻⁸ μg ml⁻¹ for herring sperm DNA. The possible mechanism of chemiluminescence in the system is discussed.     

Slurry sampling electrothermal vaporization inductively coupled plasma mass spectrometry for the determination of As and Se in soil and sludge

Slurry sampling electrothermal vaporization (ETV) inductively coupled plasma mass spectrometry (ICP-MS) has been applied to determine As and Se in soil and sludge samples. The influences of instrument operating conditions and slurry preparation on the ion signals were reported. Pd and ascorbic acid were used as mixed modifiers to enhance the ion signals. The effectiveness of ETV sample introduction technique for alleviating various spectral interferences in ICP-MS analysis has been demonstrated. This method has been applied to determine As and Se in NIST SRM 2709 San Joaquin soil reference material and NIST SRM 2781 domestic sludge reference material and a farmland soil sample collected locally. Since the sensitivities of As and Se in slurry solution and aqueous solution were different, analyte addition technique was used to determine As and Se in these samples. The As and Se analysis results of the reference materials agreed with the certified values. The precision between sample replicates was better than 5% for all determinations. The method detection limit estimated from analyte addition curves was about 0.03 and 0.02 μg g⁻¹ for As and Se, respectively, in original soil and sludge samples.     

Flow-injection chemiluminescence assay for ultra-trace determination of DNA using rhodamine B-Ce(IV)-DNA ternary system in sulfuric acid media

A novel flow-injection chemiluminescence method for the determination of DNA at ultra-trace level has been established. In 0.8 M sulfuric acid media, the chemiluminescence of the rhodamine B-cerium (IV) or Ce(IV) system is enhanced by DNA, activated previously by imidazole-HCl buffer solution (pH 7.0). The enhanced intensity of chemiluminescence is in proportion to log DNA concentration 1.0×10⁻⁸ to 0.1 μg ml⁻¹ for herring sperm DNA and 2.0×10⁻⁶ to 0.2 μg ml⁻¹ for calf thymus DNA with 3σ detection limits of 8.3×10⁻⁹ μg ml⁻¹ for herring sperm DNA and 3.5×10⁻⁷ μg ml⁻¹ for calf thymus DNA, respectively. The relative standard deviation for 1.0×10⁻⁴ μg ml⁻¹ herring sperm DNA was 0.99% and 2.0×10⁻³ μg ml⁻¹ for calf thymus DNA was 1.1% (n=11). Using the optimized system, DNA contents in six synthetic samples has been determined with recoveries of 99.5-109.0%. The possible mechanism has also been studied in this paper.     

Determination of quinolizidine alkaloids in Sophora medicinal plants by capillary electrophoresis

A new capillary electrophoresis (CE) method for the determination of quinolizidine alkaloids in Sophora medicinal plants was developed. A total of seven alkaloid components (cytisine, sophocarpine, matrine, lehmannine, sophoranol, oxymatrine and oxysophocarpine) were separated within 15 min. The running buffer was a 50 mM phosphate buffer containing 1%HP-β-CD and 3.3% isopropanol. The linear calibration ranges were 5.50-88.0 μg ml⁻¹ for cytisine and lehmannine, 5.00-88.0 μg ml⁻¹ for sophocarpine and sophoranol, 5.60-89.6 μg ml⁻¹ for matrine and oxysophocarpine, and 24.0-384 μg ml⁻¹ for oxymatrine. The recoveries of the seven alkaloids were 96.0-102.9% with relative standard deviations from 1.50 to 3.00% (n = 5). The method was successfully applied to different Sophora medicinal plants including Sophora flavescens, Sophora tonkinensis and Sophora alopecuroides.     

Flow-injection chemiluminescence determination of aminomethylbenzoic acid and aminophylline based on N-bromosuccinimide-luminol reaction

A novel and sensitive chemiluminescence (CL) method for the determination of aminomethylbenzoic acid and aminophylline coupled with flow-injection analysis (FIA) technique is developed in this paper. It is based on the inhibition effect of the studied drugs on the chemiluminescence emission of N-bromosuccinimide-luminol (NBS-luminol) system. Under the optimum conditions, the decreased CL intensity is linear with the concentration of aminomethylbenzoic acid in the range of 2×10⁻⁸ to 1.0×10⁻⁶ g ml⁻¹ and with the concentration of aminophylline in the range of 1×10⁻⁷ to 7.0×10⁻⁶ g ml⁻¹, respectively. The detection limit is 7.0×10⁻⁹ g ml⁻¹ for aminomethylbenzoic acid (3σ) and 3.4×10⁻⁸ g ml⁻¹ for aminophylline (3σ). The relative standard deviations (R.S.D.) for 11 parallel measurements of 2.0×10⁻⁷ g ml⁻¹ aminomethylbenzoic acid and 1.0×10⁻⁶ g ml⁻¹ aminophylline are 2.6 and 3.0%, respectively. The proposed methods have been applied for the determination of the studied drugs in their pharmaceutical formulations with satisfactory results. The possible use of the proposed system for the determination of aminomethylbenzoic acid in plasma sample was also tested. The possible inhibition mechanism of aminomethylbenzoic acid and aminophylline on luminol-NBS system was discussed briefly.     

Determination of thyroxine hormone by luminol chemiluminescence

A chemiluminescence (CL) flow system for determination of thyroxine (Thy) is presented. It is based on the catalytic effect of cobalt(II) on the CL reaction between luminol and hydrogen peroxide. The iodinated chemical structure of Thy causes a heavy atom effect. The luminol CL signals show significant quenching by Thy. The calibration graph for Thy is linear for 15-70 μg ml⁻¹ and the 3σ detection limits are 27 μg ml⁻¹ for d-Thy and 23 μg ml⁻¹ for l-Thy.     

Determination of traces of palladium in stream sediment and auto catalyst by FI-ICP-OES using on-line separation and preconcentration with QuadraSil TA

A flow injection analysis (FIA) method using on-line separation and preconcentration with a novel metal scavenger beads, QuadraSil™ TA, has been developed for the ICP-OES determination of traces of palladium. QuadraSil TA contains diethylenetriamine as a functional group on spherical silica beads and shows the highest selectivity for Pd(II) at pH 1 (0.1 mol l⁻¹ hydrochloric acid) solution. An aliquot of the sample solution prepared as 0.1 mol l⁻¹ in hydrochloric acid was passed through the QuadraSil TA column. After washing the column with the carrier solution, the Pd(II) retained on the column was eluted with 0.05 mol l⁻¹ thiourea solution and the eluate was directly introduced into an ICP-OES. The proposed method was successfully applied to the determination of traces of palladium in JSd-2 stream sediment certified reference material [0.019 ± 0.001 μg g⁻¹ (n = 3); provisional value: 0.0212 μg g⁻¹] and SRM 2556 used auto catalyst certified reference material [315 ± 4 μg g⁻¹ (n = 4); certified value: 326 μg g⁻¹]. The detection limit (3σ) of 0.28 ng ml⁻¹ was obtained for 5 ml of sample solution. The sample throughputs for 5 ml and 100 μl of the sample solutions were 10 and 15 h⁻¹, respectively.     

Simultaneous determination of 11 drugs belonging to four different groups in human urine samples by reversed-phase high-performance liquid chromatography method

A new, accurate, sensitive and fast reversed-phase high-performance liquid chromatography (RP-HPLC) as an analytical method for the quantitative determination of 11 drugs in human urine was worked out, optimized and validated. The objects of analysis were imipenem (IMP), paracetamol (PAR), dipyrone (DPR), vancomycin (VCM), amikacin (AMK), fluconazole (FZ), cefazolin (CFZ), prednisolone (PRE), dexamethasone (DEX), furosemide (FUR) and ketoprofen (KET) belonging to four different groups (antibiotics, analgesic, demulcent and diuretic). For HPLC analysis, diode array (DAD) and fluorescence (FL) detectors were used. The separation of analyzed compounds was conducted by means of a LiChroCART^® Purospher^® C₁₈e (125 mm × 3 mm, particle size 5 μm) analytical column with LiChroCART^® LiChrospher^® C₁₈ (4 mm × 4 mm, particle size 5 μm) pre-column with gradient elution. Analyzed drugs were determined within 20 min. The mobile phase was comprised of various proportions of methanol, acetonitrile and 0.05% trifluoroacetic acid in water. AMK was separated and determined from human urine using ortho-phthaldialdehyde-3-mercaptopropionic acid (OPA-3-MPA) as a fluorescent reagent by RP-HPLC-FL. The following retention times for drugs IMP, PAR, DPR, VCM, AMK, FZ, CFZ, PRE, DEX, FUR and KET in human urine were found: 4.01 min, 4.86 min, 6.71 min, 8.14 min, 9.46 min, 10.01 min, 10.90 min, 13.34 min, 14.06 min, 16.03 min and 18.98 min, respectively. Excellent linearity was obtained for compounds in the range of concentration: 0.35-42 μg ml⁻¹, 0.5-45 μg ml⁻¹, 4.5-38 μg ml⁻¹, 0.25-25 μg ml⁻¹, 0.5-35 μg ml⁻¹, 0.25-22 μg ml⁻¹, 0.03-52 μg ml⁻¹, 0.15-25 μg ml⁻¹, 0.25-28 μg ml⁻¹, 0.05-18 μg ml⁻¹ and 0.15-35 μg ml⁻¹ for IMP, PAR, DPR, VCM, AMK, FZ, CFZ, PRE, DEX, FUR and KET, respectively. The limits of detection (LOD) and limits of quantification (LOQ) for analyzed drugs were calculated in all cases and recovery studies were also performed. Ten human urine samples obtained from patients treated in hospital have been tested. In analyzed samples, one or more drugs from the 11 examined drugs were detected. The concentrations of examined drugs in urine samples ranged between: 1.5-12 μg ml⁻¹ of PAR, 5.2-11.5 μg ml⁻¹ of DPR, 0.13-9.5 μg ml⁻¹ of CFZ and 0.1-8 μg ml⁻¹ of FUR. This method can be successfully applied to routine determination of all these drugs in human urine samples.