Top PDF HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY FOR DETERMINATION OF AROMATIC ALDEHYDES IN WINE DISTILLATES

HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY FOR DETERMINATION OF AROMATIC ALDEHYDES IN WINE DISTILLATES

HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY FOR DETERMINATION OF AROMATIC ALDEHYDES IN WINE DISTILLATES

Abstract. Quality control of alcoholic beverages, coming into the market, is a defi ning element in preventing the production and supplying of defective products. One of the main criteria for quality control of wine distillates is to estimate their age, and more precisely the period of maturation as the dominant factor in determining the quality of cognacs and, consequently, their market price. On the opinion of majority scientists, one of the main factors, which determines the age of wine distillates, is the content of aromatic aldehydes, mostly vanillin, and their ratio.
Mostrar mais

5 Ler mais

Evaluation of solvent extraction by ultrasound by using high performance liquid chromatography for the determination of polycyclic aromatic hydrocarbons in contaminated soils.

Evaluation of solvent extraction by ultrasound by using high performance liquid chromatography for the determination of polycyclic aromatic hydrocarbons in contaminated soils.

ultraviolet absorption and luorescence detections. The detection limits, for a 10 µL of solution injection, were less than 9,917 ng/g in UV detection and less than 1,866 ng/g in luorescence detection. Several organic solvents were tested for extraction of the 17 PAHs from soils. Acetone was the best solvent among the three solvents tested, and the order of the extraction eficiencies was: acetone>methanol>acetonitrile. Ultrasonication using acetone as solvent extraction was used to evaluate the biodegradation of those compounds in contaminated soil during a vermicomposting process.
Mostrar mais

8 Ler mais

J. Braz. Chem. Soc.  vol.28 número5

J. Braz. Chem. Soc. vol.28 número5

An easy and efficient sample preparation method was developed for the determination of natamycin residues in wine samples by solvent extraction and ultra-high performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS) analysis. After choosing acetonitrile as extraction solvent, an experimental design was carried out with different amounts of C18 and primary secondary amine (PSA) sorbents in order to optimize the clean-up step. Validation results were satisfactory, with recoveries from 77 to 95% and relative standard deviation (RSD) lower than 10% for the spike levels 5, 10 and 20 µg L −1 . Method limit of detection (LOD)
Mostrar mais

7 Ler mais

J. Braz. Chem. Soc.  vol.28 número2

J. Braz. Chem. Soc. vol.28 número2

The study protocol was approved by the Ethics Committee in the Use of Animals of the Animal Welfare Policy of the Federal University of Paraná (UFPR), Curitiba city, PR, Brazil (Protocol No. 055/2011). Serum samples were provided by the Laboratory of Production and Research in Sheep and Goats (LAPOC/UFPR), Curitiba city, PR, Brazil. Weaned Suffolk breed lambs (n = 6), aged 69-83 days and body weight ranging from 32.2 to 39.0 kg, who had never received treatment with anthelmintic, were randomly selected. The animals were housed in individual pens with floor slatted suspended, equipped with individual feeders and drinkers, and fed a diet containing ryegrass hay. They received a single MOX subcutaneous injection at a dose of 0.2 mg kg -1 bw. All animals underwent a fasting
Mostrar mais

7 Ler mais

Determination of Pesticide Residues in Banana by Using High Performance Liquid Chromatography and Gas Chromatography-Mass Spectrometry

Determination of Pesticide Residues in Banana by Using High Performance Liquid Chromatography and Gas Chromatography-Mass Spectrometry

Abstract: Problem statement: The occurrence of endosulfan, carbendazim, chloropyripos in 10 banana samples in southern area of Tamilnadu, India (hill banana, karpuravalli, monthan, nendran, ney poovan, pachanadan, poovan, rasthali, red banana, robusta) was investigated. Approach: In 7 samples, Carbendazim was found at concentrations ranging from 0.002-0.11 mg kg −1 . In three samples, carbendazim was not found, whereas endosulfan, chloropyripos was not detected in any sample. Results: Analysis was carried out using HPLC-UV and samples were confirmed by GC-MS. The seven samples contained carbendazim that not exceeded the FAO/WHO codex alimentarius standards for MRLs (Maximum Residue Limit) values of carbendazim pesticide on banana (whole) is 1.0 mg kg −1 . Conclusion/Recommendations: Based on the HPLC results carbendazim is finding in Hill banana (0.007 mg kg −1 ), Monthan (0.019 mg kg −1 ), Nendran (0.002 mg kg −1 ), Pachanadan (0.007 mg kg −1 ), Poovan (0.016 mg kg −1 ), Rasthali (0.017 mg kg −1 ) and Robusta (0.11 mg kg −1 ) and carbendazim is not finding Karpuravalli, Ney poovan and Red banana. Endosulfan, Chloropyrifos and Carbendazim in Robusta Banana sample are identified by matching their retention times and characteristic ion. TIC chromatogram for a positive Robusta Banana sample.
Mostrar mais

6 Ler mais

Emprego de cromatografia líquida de alta eficiência hidrofílica na determinação dos aminoácidos de hidrolisados de caseína.

Emprego de cromatografia líquida de alta eficiência hidrofílica na determinação dos aminoácidos de hidrolisados de caseína.

USE OF HIGH PERFORMANCE LIQUID HYDROPHILIC CHROMATOGRAPHY FOR DETERMINING AMINO ACIDS IN CASEIN HYDROLYSATES. In this work, the use of hydrophilic-interaction chromatography (HILIC) was thoroughly studied for the first time in order to separate and quantify essential amino acids. Some parameters, such as the composition of the mobile phase and the flow rates were studied. The detection limit, the linearity and the repetibility of this technique were also determined. The results showed that, comparing to other methods for analysing amino acids mixtures, this technique presented some advantages, in terms of time, economy and simplicity, since the pre-column derivatisation is not needed and an isocratic condition can also be used. The utilisation of this technique for analysing the chromatography fractions of casein hydrolysates showed the importance of HILIC in the nutritional evaluation of these preparations.
Mostrar mais

4 Ler mais

J. Braz. Chem. Soc.  vol.21 número12

J. Braz. Chem. Soc. vol.21 número12

The authors have studied a TCM formula named Yi- Gong-Ning-Xue oral solution which consists of ingredients from twelve herbal plants including Radix fructus psoraleae, Coastal glehnia root, Radix polygoni multilori, Fructus ligustri lucidi, Fructus schisandrae, Radix rubiae, Herba leonuri, Radix glycyrrhizae etc. Yi-Gong-Ning-Xue in line with State Food and Drug Administration Standard WS-5092 (B-0092)-2002) is commercially available. The capsule form of this formula (YGC) is used in our study. YGC is held in TCM to be able to restore vital energy, nourish YIN, and promote kidney function and homeostasis. It is also often prescribed as adjunctive treatment for some gynecological illnesses like menometrorrhagia, prolonged and/or irregular menstruation. In a previous study, the authors demonstrated that coumarins such as psoralen, isopsoralen, imperatorin and isoimperatorin are a major group of ingredients of YGC. 3 These coumarins have
Mostrar mais

9 Ler mais

DEGRADATION OF BENZO [A] PYRENE BY A NOVEL STRAIN Bacillus subtilis BMT4i (MTCC 9447) Madhuri Kaushish Lily

DEGRADATION OF BENZO [A] PYRENE BY A NOVEL STRAIN Bacillus subtilis BMT4i (MTCC 9447) Madhuri Kaushish Lily

Present study is the first report demonstrating the utilization of BaP as a sole source of carbon and energy by bacteria. The novel strain Bacillus subtilis BMT4i (MTCC 9447) showed 10 29 fold enhancement in biomass with in 7 days and about 84.66% of BaP degradation after 28 days of growth. The HPLC profile of 7 days incubation showed six additional peaks indicating intermediate metabolites. The identification of metabolites is under study. At present it is not clear whether the decrease in CFU/ml after 7 days is due to the accumulation of toxic metabolites or exhaustion of BaP as carbon and energy source. Our study is different from other studies in following three aspects. First, all the reported BaP degradation by bacteria have been shown to occur co- metabolically i.e., in the presence of additional carbon sources. Second, none of the bacterial species showed viability for such a long duration (40 days) in BaP-BSM medium. Third, this much of high BaP degradation efficiency has not been reported by earlier studies. Early observation of BaP biodegradation was made with mutant Beijerinckia sp. strain B8/36 and Pseudomonas sp. strain NCIB 9816 grown on succinate plus biphenyl and succinate plus salicylate (1, 7). Mycobacterium vanbaalenii PYR-1 using peptone, yeast extracts, and soluble starch as the additional carbon sources was able to degrade 24.7 % of BaP in pure culture where as in sediment water microcosm experiment it was able to mineralize 36 % of added BaP after 28 days (10, 11). In
Mostrar mais

9 Ler mais

Determination of acetaldehyde in fuel ethanol by high-performance liquid chromatography with electrochemical detection

Determination of acetaldehyde in fuel ethanol by high-performance liquid chromatography with electrochemical detection

high concentration of DNPHi did not produce any visible effects on the signals of the ADNPH product generated after the reaction, which were sufficiently separated from each other. In addition to the peak corresponding to the ADNPH, some extra peaks were present, and further work identified almost all of them. These additional peaks are attributed to the presence of other carbonyl contaminants. In addition, the method was tested for several fuel ethanol samples; the relevant quantitative results are listed in Table 1. In general, the acetaldehyde content in fuel ethanol samples is significantly high, and the values point to a high concentration of acetaldehyde in the fuel, changing from concentration of 83 to 343 mg L –1 . These
Mostrar mais

4 Ler mais

METHOD DEVELOPMENT AND VALIDATION OF RP-HPLC METHOD IN THE DETECTION OF EFAVIRENZ IN BULK DRUG AND TABLET FORMULATION

METHOD DEVELOPMENT AND VALIDATION OF RP-HPLC METHOD IN THE DETECTION OF EFAVIRENZ IN BULK DRUG AND TABLET FORMULATION

Linearity: Appropriate aliquots of drug were pipette out from the standard stock solution into a series of 10ml volumetric flasks. The volume was made up to the mark with mobile phase to obtain concentration levels of efavirenz ranging from 25-200 μg/ ml. Triplicate dilutions of each concentration of drug were prepared separately and chromatographed under the optimized conditions. Analysis of drug was performed with the UV detector set at 284nm and peak area was recorded. The graph was plotted between concentration and area under peak for linearity.
Mostrar mais

4 Ler mais

Comparison of capillary electrophoresis and high performance liquid chromatography methods for caffeine determination in decaffeinated coffee

Comparison of capillary electrophoresis and high performance liquid chromatography methods for caffeine determination in decaffeinated coffee

Jimidar et al. (1993) compared HPLC and CE methods to determine caffeine, aspartame, and benzoic acid in diet cola soft drinks and in artificial sweeteners. They found that relative standard deviations for reproducibility were significantly higher in CE than in HPLC. The separation efficiency of CE was 65- 110-fold higher than that of HPLC, while 10-20-fold lower detection limits were obtained in HPLC. In addition, the matrix effect was higher for CE. Lee and Ong (2000), in comparative studies of these two techniques to evaluate the catechins levels in tea, found that the CE method provided faster results, whereas the HPLC method showed lower detection limits. Kowalski et al. (2007), when comparing the same techniques in the analysis of cotinine in human plasma, verified that the CE method required smaller amounts of reagents, while the HPLC method resulted in lower detection limits. Furthermore, Sombra et al. (2005), while investigating synthetic adulterants in plant protection, also concluded that the CE method was faster, and that the HPLC method had lower detection limits. Conversely, Kowalski and Plenis (2007), in a quantification study on cetirizine di-hydrochloride in human plasma, obtained faster analysis using the HPLC, equivalent detection limits between the two methods, and lower solvent consumption with the CE method. In those studies, the costs, composition and volume of residues generated, and the required treatment and its cost were not measured and compared directly. In addition, there are no comparative studies available on the residual caffeine in decaffeinated coffee samples.
Mostrar mais

6 Ler mais

Determination of the Triacylglycerol Composition of Coffee Beans by Reverse-phase High-performance Liquid Chromatography

Determination of the Triacylglycerol Composition of Coffee Beans by Reverse-phase High-performance Liquid Chromatography

Coffee samples. About 10 kg of coffee beans (Coffea ara- bica L.; Catuaí Vermelho) were harvested in Machado or Viçosa (Minas Gerais, Brazil) by the ‘derriça’ method (that is beans were removed by hand from the tree and allowed to drop to the floor which had been covered with a cloth). From this population, a mixture of beans was obtained by separating 5 kg randomly. From the remainder of the population, the imma- ture and cherry beans were separated by placing the beans in a tank containing 50 L of water. The dry beans floated immediately and were removed, while the imma- ture and cherry beans remained at the bottom of the tank. After draining the tank, the immature and the cherry beans were separated by hand and allowed to dry in the air for 20 h. One portion of each of the samples of beans so obtained [i.e. random mixture (Viçosa beans only), immature and cherry] was dried separately in a conventional dryer at 40°C for 40 h to ca. 12% humidity. The other portion (Viçosa beans only) was dried on a patio for 10–12 days to a humidity of ca. 14%. In this way a total of eight bean samples (T 1 –T 8 ) were obtained
Mostrar mais

5 Ler mais

Determination of 2,5-hexanedione in urine by high performance liquid chromatography after derivatization with 2,4-dinitrophenilhidrazine.

Determination of 2,5-hexanedione in urine by high performance liquid chromatography after derivatization with 2,4-dinitrophenilhidrazine.

DETERMINATION OF 2,5-HEXANEDIONE IN URINE BY HIGH PERFORMANCE LIQUID CHROMATOGRAPHY AFTER DERIVATIZATION WITH 2,4-DINITROPHENILHIDRAZINE. A method for quantifying urinary 2,5-hexanedione was optimized and validated. Urine samples were hydrolyzed and derivatized with 2,4-dinitrophenylhydrazine. The analyte was separated in a high performance liquid chromatography system with a diode array detector, using a C18 column (150 x 4.6 mm, p.d. 5 μm) and a mobile phase composed of phosphate buffer pH 2.3:acetonitrile (40:60, v/v), at a low rate of 1 mL/min. The chromatograms were monitored at 334 nm. Retention time was 7.3 minutes. Main validation parameters were: coeficient of determination: 0.9994, accuracy: 96 to 107%; intra-assay precision (RSD): 3.08 to 6.72%; inter-assay precision (RSD): 2.54 to 8.17% and limit of quantitation of 0.19 μg/mL.
Mostrar mais

5 Ler mais

Determination of harpagoside in Harpagophytum procumbens DC tablet’s using analytical method by High Performance Liquid Chromatography

Determination of harpagoside in Harpagophytum procumbens DC tablet’s using analytical method by High Performance Liquid Chromatography

In this study, the accuracy evaluation was done using the standard addition method, using nine determinations with three levels of theoretical concentration (low, medium and high) in triplicate for each level. In the case of finished product, according to the Brazilian legislation, if samples of all drug components are unavailable, analysis by the standard chemical addition method may be performed, in which know quantities of reference chemical are added to the solution of the finished prduct 17 . The theoretical concentrations used were calculated at 80, 100 and 120%; these concentrations were achieved using 500 μL of the commercial H. procumbens sample with 500 μL of the harpagoside standard. The harpagoside recovery percentage added to the sample was evaluated by the relation between the experimentally determined concentration and the corresponding theoretical concentration.
Mostrar mais

9 Ler mais

Simultaneous determination of carbamazepine, phenytoin and phenobarbital in dried blood spots by high performance liquid chromatography.

Simultaneous determination of carbamazepine, phenytoin and phenobarbital in dried blood spots by high performance liquid chromatography.

Um método para a determinação simultânea de CBZ, FNB e FNT em MSS empregando cromatografia líquida de alta eficiência com detector de arranjo de diodos foi desenvolvido e validado, apresen- tando características de desempenho analítico que permitem a sua utilização clínica. Os analitos foram estáveis por até 12 dias à tem- peratura ambiente e em refrigeração. Empregando as concentrações determinadas em MSS e fatores de multiplicação obtidos in vitro foi possível estimar concentrações em soro em valores entre 80 e 105% dos valores séricos efetivamente mensurados.
Mostrar mais

5 Ler mais

Braz. J. Pharm. Sci.  vol.47 número2

Braz. J. Pharm. Sci. vol.47 número2

Liquid-liquid extraction is simple and a large num- ber of solvents, pure and commercially available, can be used which provide a wide range of solubility and selectiv- ity. Furthermore, the proteins present in the samples are denatured, eliminating the contamination of the chromato- graphic column (Queiroz, Collins, Jardim, 2001). Coe et al. (1996) reported an LLE procedure for the analysis of luoruracil in plasma samples, using the pH adjustment to 6.0 by adding acetate buffer, followed by a saturated solution of sodium sulfate and 7.0 mL of ethyl acetate, with around 46% of recovery (Coe et al., 1996). For the ifosfamide and cyclophosphamide isomers, Turci et al. (2002) proposed an LLE for urine samples in which 5 mL of sample was adjusted to pH 7, then extracted three times with 10 mL of ethyl acetate (Turci et al., 2002). A percent- age of 85% for both analytes was obtained. Kümmerle et al. (2003) proposed an LLE for DOX using 500 µL of biological luid, pre-treated with a precipitation of the protein, then 250 µL of acetone and 50 µL of an aqueous solution of zinc sulfate 70% as a solvent extractor were added (Kümmerle et al., 2003). In our study, the principles of liquid-liquid extraction were optimized according to the following steps: type and volume of extractor solvent, shaking velocity, number of extractions totaling 10 mL and salting-out effect.
Mostrar mais

9 Ler mais

Development and validation of analytical method for determination of tibolone in capsules by high performance liquid chromatography.

Development and validation of analytical method for determination of tibolone in capsules by high performance liquid chromatography.

DEVELOPMENT AND VALIDATION OF ANALYTICAL METHOD FOR DETERMINATION OF TIBOLONE IN CAPSULES BY HIGH PERFORMANCE LIQUID CHROMATOGRAPHY. Tibolone is a synthetic steroid used for prevention of bone loss and treatment of menopause symptoms. This article describes the development and validation of an analytical method to quantify tibolone in capsules using high performance liquid chromatography with UV detection. After chromatography conditions are established the validation parameters evaluated were specificity, linearity, precision, accuracy, detection and quantification limits and robustness. The method developed is effective to analyze tibolone in capsules, being able to be used in quality control laboratory routine.
Mostrar mais

6 Ler mais

Determination of free urinary cortisol in cushing's syndrome using reversed-phase high performance liquid chromatography

Determination of free urinary cortisol in cushing's syndrome using reversed-phase high performance liquid chromatography

Tables 2 and 3 show the results obtained for samples submitted to the RP-HPLC method. In 30 determinations made with samples from 19 patients, the values ranged between 3.30 and 863 µg/24 h. Regar- ding the reference value (55.0 µg/24 h), 36.6% of the obtained results were suggestive of a Cushing’s syndrome diagnosis. As these samples were obtained from patients under clinical evaluation, we were able to compare the results with the corresponding diagnoses, conirmed by the pathological, imaging, and petrosal sinus catheterism examinations. The results of the samples numbered from 1 to 12 (Table 2) were evaluated for cortisol in serum and/or saliva and correspond to data supplied by the routine laboratory. Cortisol measurement by RIA was performed using an adapted laboratory routine. 21 The concentration in
Mostrar mais

4 Ler mais

Chiral stationary phases for high-performance liquid chromatography.

Chiral stationary phases for high-performance liquid chromatography.

CHIRAL STATIONARY PHASES FOR HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY. The development of Chiral Stationary Phases (CSPs) for high performance liquid chromatography has been studied by various researches around the world, especially, since 1980. This simple interest has been transformed into a tool of great technological value for the industrial community and scholars in general providing the existence of several CSPs, which act through different mechanisms of chiral discrimination. This paper describes the main types of CSPs that are used for the resolution of the majority of chiral compounds.
Mostrar mais

10 Ler mais

Sulfadimethoxyne quantification in milk by high performance liquid chromatography.

Sulfadimethoxyne quantification in milk by high performance liquid chromatography.

SULFADIMETHOXYNE QUANTIFICATION IN MILK BY HIGH PERFORMANCE LIQUID CHROMATOGRAPHY. A method for HPLC determination of sulfadimethoxyne in milk is presented. The analyte isolation and concentration were performed by solid- phase extraction through a C-8 cartridge, pre-conditioned with hexane, methanol and water and eluted with MeOH. The recovery determination was done with a spiked solution of 20, 50 or 100 µg L -1 . In this concentration range, the recovery was 83.2% with a

3 Ler mais

Show all 10000 documents...

temas relacionados