Determination of guaiphenesin and sodium benzoate in Liqufruta garlic cough medicine by high performance liquid chromatography

A new and simple isocratic high-performance liquid chromatographic method with ultraviolet detection is described for simultaneous determination of active guaiphenesin and preservative sodium benzoate in Liqufruta garlic cough medicine formulation. The chromatographic separation was achieved using a Zorbax CN; 150 mm × 4.6 mm and 5 μm particle size column employing acetonitrile and water (20: 80, v/v) containing 0.1% formic acid (pH 3.5 ± 0.05) as the mobile phase. The method was validated with respect to linearity, range, precision, accuracy, specificity, limit of detection and limit of quantitation. The both analytes were detected by UV-Vis detector at 245 nm. The method was linear over the concentration range of 0.2–0.8 mg/mL and 0.02–0.06 mg/mL for guaiphenesin and sodium benzoate, respectively. The limit of detection was found to be 0.14 μg/mL for GP and 0.06 μg/mL for SB and the quantification limit was 0.54 μg/mL for GP and 0.22 for SB. Accuracy, evaluated as recovery, was in the range of 97.8–100.0%. Intra-day precision and intermediate precision showed relative standard deviation <1% in each case.     

Development and validation of the HPLC method for the analysis of trimetazidine hydrochloride in bulk drug and pharmaceutical dosage forms

A simple, economic, selective, precise, and accurate high-performance liquid chromatographic (HPLC) method for the analysis of trimetazidine hydrochloride in both bulk drug and pharmaceutical formulations was developed and validated in the present study. The mobile phase consisted of water: methanol: triethylamine (75: 25: 0.1 v/v/v), and pH 3.3 was adjusted with orthophosphoric acid. This system was found to give a sharp peak of trimetazidine hydrochloride at a retention time of 3.375 ± 0.04 min. HPLC analysis of trimetazidine hydrochloride was carried out at a wavelength of 232 nm with a flow rate of 1.0 mL/min. The linear regression analysis data for the calibration curve showed a good linear relationship with a regression coefficient of 0.997 in the concentration range of 5–90 μg/mL. The linear regression equation was y = 35362x − 8964.2. The limit of detection (LOD) and limit of quantification (LOQ) were found to be 3.6 and 10.9 μg/mL, respectively. The developed method was employed with a high degree of precision and accuracy for the analysis of trimetazidine hydrochloride. The developed method was validated for accuracy, precision, robustness, detection, and quantification limits as per the ICH guidelines. The wide linearity range, accuracy, sensitivity, short retention time, and composition of the mobile phase indicated that this method is better for the quantification of trimetazidine hydrochloride. The text was submitted by the authors in English.     

Determination of imidacloprid in paddy water and soil by liquid chromatography electrospray ionization-tandem mass spectrometry

A method for the determination of imidacloprid in paddy water and soil was developed using liquid chromatography electrospray ionization-tandem mass spectrometry (LC/ESI-MS/MS). Separation of imidacloprid was carried out on a Shimadzu C18 column (150 mm × 4.6 mm, 4.6 μm) with an acetonitrile-water (50: 50, v/v) mobile phase containing 0.1% of acetic acid. The flow rate was 0.3 mL/min in isocratic mode. The product ion at 209 m/z was selected for quantification in multiple-reaction monitoring scan mode. Imidacloprid residues in soil were extracted by a solid-liquid extraction method with acetonitrile. Water samples were filtered and directly injected for analysis without extraction. Detection limits of 0.5 μg/kg and 0.3 μg/L were achieved for soil and water samples, respectively. The method had recoveries of 90 ± 2% (n = 4) for soil samples and 100 ± 2% (n = 4) for water samples. A linear relationship was observed throughout the investigated range of concentrations (1–200 μg/L), with the correlation coefficients ranging from 0.999 to 1.000.     

Optimization of a high-performance liquid chromatography method to quantify bilirubin and separate it from its photoproducts

A rapid reversed-phase (RP) high-performance liquid chromatography method for the isolation of bilirubin from its photoproducts (e.g., biliverdin) is reported. The method is based on isocratic elution using methanol:water as the mobile phase. A 2⁴ full-factorial experimental design approach was adopted. For the optimization, the best separation was obtained using a flow rate of 1.50 mL/min, a mobile phase of 99∶1 methanol:water (v/v) at pH 3.60, and a 150×4.6 mm id RP (C₁₈) column containing 5-μm particles. These conditions produced the fastest total retention time of 3.38±0.055 min, and other chromatographic parameters were acceptable. Under the optimum conditions, a linear calibration curve for bilirubin was obtained over the 1.0–40.0 μg/L concentration range studied. The limit of quantification was 0.79 g/L and the limit of detection was 0.24 μg/L. Bilirubin in solution was monitored by ultraviolet detection at 450 nm.     

Simultaneous quantification of cefpirome and cetirizine or levocetirizine in pharmaceutical formulations and human plasma by RP-HPLC

A rapid and sensitive high-performance liquid chromatographic (HPLC) assay for the simultaneous determination and quantification of cefpirome and cetirizine or cefpirome and levocetirizine in pharmaceutical formulations and human plasma without changing the chromatographic conditions is described. Chromatographic separations were performed on a prepacked Nucleosil 120, C₁₈ (5 μm, 12.5 ± 0.46 mm) column using CH₃CN: H₂O (75: 25, v/v) as a mobile phase at a flow rate of 1 mL/min while UV detection was performed at 232 nm for monitoring the effluent. A number of other brands of C₁₈ columns were also employed which had a significant effect on the separation. The method has been validated over the concentration range of 0.5–50 μg/mL (r ₂ > 0.999). The limit of detection (LOD) and quantification (LOQ) for cefpirome and levocetirzine in pharmaceutical formulations and serum were in the range 0.24–1.31 μg/mL. Analytical recovery from human plasma was >98%, and the within and between-day relative standard deviation was <3.1%. The small sample volume and simplicity of preparation make this method suitable for use in pharmaceutical industries, drug research centers, clinical laboratories, and forensic medical centers. The text was submitted by the authors in English.     

HPLC assay method for ceftibuten in plasma and its application to pharmacokinetic study

The purpose of this study was to validate a reliable analytical method for pharmacokinetic study of ceftibuten in human plasma by high performance liquid chromatography (HPLC) system with UV detection. Ceftizoxime was used as the internal standard. After plasma sample was precipitated with acetonitrile and dichloromethane, the supernatant was directly injected into the HPLC system. Separation was performed on a Capcell Pak C₁₈ UG120 column (4.6 mm × 250 mm, 5 μm particles) with a mobile phase of acetonitrile/50 mM ammonium acetate (5: 95, v/v) and UV detection at a wavelength of 262 nm. The intra- and inter-day precision expressed as the relative standard deviation was less than 15%. The lower limit of quantification was 0.5 hg/mL of ceftibuten using 0.5 mL of plasma. The calibration curve was linear in concentration range of 0.5–30 μg/mL (r ² = 0.9998). The mean accuracy was 96–102%. The coefficient of variation (precision) in the intra- and inter-day validation was 0.9–3.9 and 0.9–2.4%, respectively. The pharmacokinetics of ceftibuten was evaluated after a single oral administration of 400 mg to healthy volunteers. The AUC_{0–9 h}, c _max, T _max, and T _1/2 were 86.6 ± 12.7 μg h/mL, 18.4 ± 1.5 μg/mL, 2.63 ± 0.83 and 2.65 ± 0.41 h, respectively. The method was demonstrated to be highly reproducible and feasible for pharmacokinetic studies of ceftibuten in eight volunteers after oral administration (400 mg as ceftibuten).     

GC-FID optimization and validation for determination of 3,4-methylenedioxymethamphetamine, 3,4-methylenedioxyamphetamine and methamphetamine in ecstasy tablets

A methodology for the determination of 3,4-methylenedioxymethamphetamine (MDMA), 3,4-methylenedioxyamphetamine (MDA) and methamphetamine (MA) in seized tablets using gas chromatography with a flame ionization detector (GC-FID) is described. The chromatographic conditions, i.e. gas flow rates and temperatures for the column, injector and detector were optimized. The optimum chromatographic conditions were as follows: a CP-SIL 24 CB WCOT fused silica capillary column (30 m × 0.32 mm I.D., 0.25 μm film thickness), N₂ carrier gas flowing at 2.6 mL/min, injector temperature at 290°C and detector temperature at 300°C. The oven temperature was ramped from 80°C at a rate of 20°C/min to final temperature of 270°C (1 min). All analytes were well separated within 7 min with an analysis time of 10.5 min. Calibration curves were linear over the concentration ranges of 3.125–200 μg/mL for MDMA and 6.25–200 μg/mL for MDA and MA (r > 0.990). The intra- and inter-day precisions for determining all analytes were 2.32–10.38% RSD and 1.15–9.77% RSD, respectively. The intra- and inter-day accuracies ranged from −19.79 to +17.51% DEV and −6.84 to +5.2% DEV, respectively. The lower limits of quantification (LLOQs) were 3.125 μg/mL for MDMA and 6.25 μg/mL for MDA and MA. All analytes were stable at room temperature during 24 h but significant loss occurred after 2-month storage at −20°C. The method was shown to be useful for determining the purity of MDMA in seized tablets.     

Validation of a high-performance chromatographic method for determination of cefotaxime in biological samples

An analytical method for detecting and quantifying cefotaxime in plasma and several tissues is described. The method was developed and validated using plasma and tissues of rats. The samples were analyzed by reversed phase liquid chromatography (HPLC) with UV detection (254 nm). Calibration graphs showed a linear correlation (r > 0.999) over the concentration ranges of 0.5–200 μg/mL and 1.25–25 μg/g for plasma and tissues, respectively. The recovery of cefotaxime from plasma standards prepared at the concentrations of 25 μg/mL and 100 μg/mL was 98.5 ± 3.5% and 101.8 ± 2.2%, respectively. The recovery of cefotaxime from tissue standards of liver, fat and muscle, prepared at the concentration of 10 μg/g was: 89.8 ± 1.2% (liver), 103.9 ± 6.5% (fat) and 97.8 ± 2.1% (muscle). The detection (LOD) and quantitation (LOQ) limits for plasma samples were established at 0.11 μg/mL and 0.49 μg/mL, respectively. The values of these limits for tissues samples were approximately 2.5 times higher: 0.3 μg/g (LOD) and 1.25 μg/g (LOQ). For plasma samples, the deviation of the observed concentration from the nominal concentration was less than 5% and the coefficient of variation for within-day and between-day assays was less than 6% and 12%, respectively. The method was used in a pharmacokinetic study of cefotaxime in the rat and the mean values of the pharmacokinetic parameters are given. Received: 25 May 1998 / Revised: 27 July 1998 / Accepted: 1 August 1998     

Simultaneous analysis of sarin, pyridostigmine bromide and their metabolites in rat plasma and urine using HPLC

Summary A method was developed for the separation and quantification of the warfare nerve agent sarin (O-isopropylmethylphosphonoflouridate), its metabolite methylphosphonic acid, the anti nerve agent drug pyridostigmine bromide (PB;3-dimethylaminocarbonyloxy-N-methyl pyridinium bromide) and its metaboliteN-methyl-3-hydroxypyridinium bromide in rat plasma and urine. The method involved using solid phase extraction and high performance liquid chromatography (HPLC) with reversed phase C₁₈ column, and UV detection at 280 nm. The compounds were separated using gradient of 1% to 55% acetonitrile in 0.1% triflouroacetic acid water solution (pH 3.20) at flow rate of 0.9 ml/min in a period of 15 min. The retention times ranged from 4.4–12.1 min. The limits of detection were 50 ng mL⁻¹ for PB andN-methyl-3-hydroxypyridinium bromide, and 10 μg mL⁻¹ for sarin and methylphosphonic acid, while limits of quantitation were between 100 ng mL⁻¹–12 μg mL⁻¹. Average percentage recovery of five spiked samples from plasma were 84.6±8.4, 86.5±9.0, 76.4±8.5, 81.3±8.2, and from urine 78.5±7.9, 76.4±7.8, 74.4±8.4, 80.6±6.8 for sarin, methylphosphonic acid, pyridostigmine bromide andN-methyl-3-hydroxypyridinium bromide, respectively. This method was applied to analyze the above chemicals and metabolites following combined administration in rats.     

Determination of ambroxol hydrochloride in tablets using flow-injection UV spectrophotometry and HPLC

A flow-injection UV spectrophotometric method was developed for the determination of ambroxol hydrochloride in tablets. The quantitative determination of ambroxol was performed at 245 nm using distilled water as the carrier solvent. In this study, the flow rate, loop volume, and the number of injections per hour were 15 mL/min, 193 μL, and 100, respectively. The analytical signal of ambroxol was linear in the concentration range of 40–200 μg/mL. The detection limit and limit of quantification were found as 11.55 and 38.49 μg/mL, respectively. The results for the determination of ambroxol in tablets, 29.99 ± 0.23 mg (mean ± SD), were in good agreement with the labeled quantities (30 mg/tablet). A relatively high recovery value (100.4%) shows the accuracy of the proposed method. Furthermore, the results obtained were in accordance with those obtained by the HPLC method, which were used as a comparison method for the determination of ambroxol HCl, as far as the Student’s t-test and Fisher test results were concerned. It was concluded that the proposed flow-injection UV spectrophotometric method was fast, accurate, precise, and suitable for automation in the determination of ambroxol. The text was submitted by the authors in English.     

Development and validation of an HPLC-UV method for the simultaneous quantification of carbamazepine, oxcarbazepine, eslicarbazepine acetate and their main metabolites in human plasma

For the first time, a simple, selective and accurate high-performance liquid chromatography method with ultraviolet detection was developed and validated to quantify simultaneously three structurally related antiepileptic drugs; carbamazepine, oxcarbazepine, and the recently launched eslicarbazepine acetate and their main metabolites, carbamazepine-10,11-epoxide, 10,11-trans-dihydroxy-10,11-dihydro-carbamazepine, and licarbazepine. The method involves a solid-phase extraction and a reverse-phase C18 column with 5 cm length. The mobile phase consisting of water, methanol, and acetonitrile in the ratio 64:30:6 was selected as the best one and pumped at 1 mL/min at 40 °C. The use of this recent column and an aqueous mobile phase instead of buffers gives several advantages over the method herein developed; namely the fact that the chromatographic analysis takes only 9 min. The method was validated according to the guidelines of the Food and Drug Administration, showing to be accurate (bias within ±12%), precise (coefficient variation <9%), selective and linear (r ² > 0.997) over the concentration range of 0.05–30 μg/mL for carbamazepine; 0.05–20 μg/mL for oxcarbazepine; 0.15–4 μg/mL for eslicarbazepine acetate; 0.1–30 μg/mL for carbamazepine-10,11-epoxide; 0.1–10 μg/mL for 10,11-trans-dihydroxy-10,11-dihydro-carbamazepine, and 0.1–60 μg/mL for licarbazepine. It was also shown that this method can adequately be used for the therapeutic drug monitoring of the considered antiepileptic drugs, carbamazepine, oxcarbazepine, eslicarazepine acetate, and their metabolites.     

Preconcentration of 2,4-dichlorophenoxyacetic acid on molecularly imprinted polymers and its subsequent determination by high performance liquid chromatography

The potency of molecularly imprinted polymers (MIP) for 2,4-dichlorophenoxyacetic acid (2,4-D) in the dynamic sorption preconcentration (solid phase extraction) of 2,4-D and three other structurally related species (2,4-dichlorophenol, 2-chlorophenol, and dikamba) from aqueous solutions is assessed. The optimal conditions for preconcentration are found: 0.01 M HCl, 25–100 mL of solution, flow rate of solution 0.7 mL/min, column (15 × 2.7 mL), and sorbent weight 0.04 g. The analytes are desorbed with 1 mL of methanol and detected in the eluate by reversed-phase HPLC with spectrophotometric detection at 225 nm. The detection limit for 2,4-D makes 0.4 μg/mL without preconcentration and 0.01 μg/mL with preconcentration from a volume of 100 mL. The procedure is applied to the analysis of model mixtures based on fresh river water.     

Determination of roxythromycin in blood serum by liquid chromatography with mass spectrometric detection

A procedure has been developed for the determination of a macrolide antibiotic roxythromycin (RX) in blood serum using HPLC with mass spectrometric detection using clarithromycin (CL) as the internal standard. RX and CL have been extracted from the samples by solid-phase extraction in a cartridge filled with a polar adsorbent, cyanopropylsilyl silica gel. The absolute recoveries of RX and CL are 89.6 and 92.5%, respectively. Chromatographic separation has been performed on a Nucleodur C₁₈ Isis column with the mobile phase composed as follows: water-methanol-acetonitrile-formic aid (499: 250: 250: 1 by volume). Registration has been performed in the mode of selected ion monitoring with m/z 837.7 (RX) and m/z 748.7 (CL). The analytical range for RX is 0.097–14.81 μg/mL, the quantification limit is 0.097 μg/mL, the detection limit is 0.03 μg/mL, and the intraday and interday relative standard deviation are 2–6 and 4–8% respectively. The procedure has been applied to the pharmacokinetic studies of the Rulid pharmaceutical preparation.     

Extraction–thermal lens quantification of cobalt with Nitroso-R-Salt in two-phase aqueous systems with water-soluble polymer polyethylene glycol

A novel method is proposed for the extraction-thermal lens quantification of cobalt with Nitroso-R-Salt based on the distribution of the colored complex in a two-phase aqueous system on the basis of poly-ethylene glycol (PEG) and an ammonium sulfate solution followed by its thermal lens detection in the extract. The limit of detection is 0.3 μM (20 ng/mL); the lower limit of the analytical range is 0.7 μM (40 ng/mL); the relative standard deviation for the concentrations 1–50 μM makes 1–3% (n = 6, P = 0.95). In the determination of cobalt by spectrophotometry under the same conditions, the detection limit is 10 μM (0.6 μg/mL) and the lower limit of the analytical range is 40 μM (2.5 μg/mL). The precision of thermal lens measurements in PEG solutions is higher in comparison to that in aqueous ones because of the weaker interference of convection in aqueous solutions of PEG.     

Determination of carbaryl in foods by solid-phase room-temperature phosphorimetry

A phosphorimetric solid phase assay is proposed for the determination of the pesticide carbaryl (CBL) at room temperature. CBL was spotted on filter paper together with Tl(I) as heavy metal, and dried for 3 min, after which the diffuse transmitted phosphorescence was measured using two quartz plates to avoid the quenching effect produced by atmospheric oxygen. The linear dynamic range was 0.5–4.0 μg/mL and the detection and quantification limits were 0.09 and 0.31 μg/mL, respectively. The precision of the method, expressed as relative standard deviation, was 2.3% for a sample containing 2.0 μg/mL of CBL. The method was applied to the determination of CBL residues in cereals, potatoes and waters, obtaining recoveries ranging between 92 and 105%. Received: 10 October 1997 / Revised: 2 February 1998 / Accepted: 7 February 1998     

Determination of Trihalomethanes in Drinking Water by Dispersive Liquid–Liquid Microextraction then Gas Chromatography with Electron-Capture Detection

Dispersive liquid–liquid microextraction (DLLME) has been used for preconcentration of trihalomethanes (THMs) in drinking water. In DLLME an appropriate mixture of an extraction solvent (20.0 μL carbon disulfide) and a disperser solvent (0.50 mL acetone) was used to form a cloudy solution from a 5.00-mL aqueous sample containing the analytes. After phase separation by centrifugation the enriched analytes in the settled phase (6.5 ± 0.3 μL) were determined by gas chromatography with electron-capture detection (GC–ECD). Different experimental conditions, for example type and volume of extraction solvent, type and volume of disperser solvent, extraction time, and use of salt, were investigated. After optimization of the conditions the enrichment factor ranged from 116 to 355 and the limit of detection from 0.005 to 0.040 μg L⁻¹. The linear range was 0.01–50 μg L⁻¹ (more than three orders of magnitude). Relative standard deviations (RSDs) for 2.00 μg L⁻¹ THMs in water, with internal standard, were in the range 1.3–5.9% (n = 5); without internal standard they were in the range 3.7–8.6% (n = 5). The method was successfully used for extraction and determination of THMs in drinking water. The results showed that total concentrations of THMs in drinking water from two areas of Tehran, Iran, were approximately 10.9 and 14.1 μg L⁻¹. Relative recoveries from samples of drinking water spiked at levels of 2.00 and 5.00 μg L⁻¹ were 95.0–107.8 and 92.2–100.9%, respectively. Comparison of this method with other methods indicates DLLME is a very simple and rapid (less than 2 min) method which requires a small volume of sample (5 mL).     

Chromatographic and electrophoretic determination of thioamides based on thiazole, 1,3,4-thiadiazole, 1,2,4-triazole,and tetrazole

A procedure was developed for the determination of the following thioamides based on thiazole, 1,3,4-thiadiazole, 1,2,4-triazole, and tetrazole: 2-mercaptothiazole (I), 2-mercapto-1,3,4-thiadiazole (II), 2-mercapto-5-methyl-1,3,4-thiadiazole (III), 3-mercapto-1,2,4-triazole (IV), 3-mercapto-4-methyl-1,2,4-triazole (V), and 5-mercapto-1-methyltetrazole (VI). The determination was performed by reversed-phase HPLC on a column (150 × 4 mm) packed with Diaspher-110-C18 (5 μm) using elution with an acetonitrile-acetate buffer solution (pH 4.70) mixture (5: 95). Detection was performed at the light absorption maximums of compounds I (320 nm), II (305 nm), III (310 nm), IV (260 nm), V (254 nm), and VI (245 nm). The calibration graphs were linear over the following concentration ranges (μg/mL): 0.47–11.72 (I), 0.47–11.82 (II), 0.53–13.22 (III), 0.40–10.11 (IV), 0.46–11.52 (V), and 0.46–11.62 (VI). The limits of detection were 0.45, 0.43, 0.50, 0.37, 0.41, and 0.42 μg/mL for compounds I–VI, respectively. Conditions for the separation of a mixture of compounds I and III–V and for the quantitative determination of compounds I–VI by capillary zone electrophoresis (CZE) were optimized. CZE was performed on a quartz capillary of size 60 cm (effective length of 50 cm) × 75 μm at a voltage of 20 kV with a borate buffer solution (pH 9.18). The procedure allowed us to evaluate the concentrations of substances in the ranges of 1.17–93.75 (I), 1.18–94.54 (II), 1.32–105.76 (III), 1.01–101.13 (IV) 1.15–115.16 (V), and 1.16–116.15 (VI) μg/mL with the detection limits of 1.10, 1.11, 1.20, 0.96, 1.01, and 1.02 μg/mL for compounds I–VI, respectively.     

Determination of hydrazine by liquid chromatography with preliminary derivatization with naphthalene-2,3-dialdehyde

A method is proposed for the quantification of hydrazine by reversed-phase chromatography after its derivatization with naphthalene-2,3-dialdehyde. The conditions of derivatization and the chromatography separation on a Zorbax Eclipse XDB-C8 column in the gradient mode are optimized. The derivatization and chromatography analysis take 1 and 16 min, respectively. If fluorimetry detection (λ_ex = 273 nm, λ_em = 500 nm) is used and the injection volume is 100 μL, the detection limit is 0.05 μg/L. The procedure is applicable to the quantification of hydrazine in natural waters and soil extracts. A simple and rapid procedure is elaborated for the determination of 0.1–50 μg/L hydrazine in natural waters, RSD = 12% (n = 3).     

Spectrophotometric determination of piroxicam

The possibility of the spectrophotometric determination of piroxicam based on the extraction of its ion associate (IA) with the polymethine dye, 5-thiocyanate-1,3,3-trimethyl-2[(1E)-3-[(2E)-1,3,3-trime-thyl-1-H-indol-2-ilidine]-propenyl]-3H-indolium chloride. The maximal recovery of IA with toluene is achieved when pH of the aqueous phase is 8.0–12.0 and the concentration of the dye is (1.0–2.0) × 10⁻⁴. The molar absorption coefficient of IA is 8 × 10⁴, the detection limit of piroxicam is 0.49 μg/mL. A procedure has been developed for the extraction-spectrophotometric determination of piroxicam in the concentration range 1.0–20.0 μg/mL.     

A validated method for the quantification of curcumin in plasma and brain tissue by fast narrow-bore high-performance liquid chromatography with fluorescence detection

Curcumin, a lipophilic polyphenol derived from the rhizome of the plant turmeric (Curcuma longa), might be useful in the prevention and treatment of a number of degenerative brain disorders, including glioma multiforma and Alzheimer’s disease. Thus, there is growing interest in measuring curcumin concentrations in the brain and other target tissues in relevant animal models. We therefore developed and validated (according to the Food and Drug Administration guidelines for bioanalytical method validation), a simple, fast and reliable method for the quantification of curcumin in biological matrices by fast high-performance liquid chromatography with fluorescence detection. This method involves a simple extraction with 95% ethyl acetate and 5% methanol, rapid separation (<2 min if external standards and <4 min if the internal standard β-estradiol 17-acetate is used) on a Jasco Reprosil-Pur Basic C₁₈ column (75 × 2 mm, 1.8 μm) with an eluent of acetonitrile, methanol, de-ionised water and acetic acid (49:20:30:1, v/v; flow rate, 0.4 mL/min) and fluorescence detection (excitation wavelength, 420 nm; emission wavelength, 470 nm). The method is selective, precise (<15% RSD at the lower limit of quantification), accurate (<15% of the coefficient of variation at the lower limit of quantification) and sensitive over a linear range of 0.05–10 μg/mL for curcumin. The developed method was used for the quantification of curcumin in the brains of mice force-fed (50 mg/kg bw) or i.p. injected (100 mg/kg bw) with curcumin. Brain curcumin concentrations of the mice were below the limit of detection at 30, 60 and 120 min after oral gavage and reached 4–5 μg/g brain 20–40 min after i.p. injection. In conclusion, the developed and validated method should be useful for the accurate and precise quantification of curcumin in target organs from relevant animal models of human diseases.