scholarly journals Simultaneous determination of Cd and Pb in antibiotics used in sugar-cane fermentation process by GFAAS

2006 ◽  
Vol 31 (2) ◽  
pp. 7-12 ◽  
Author(s):  
V. R. Amorim Filho ◽  
W. L. Polito ◽  
S. R. Oliveira ◽  
G. P. G. Freschi ◽  
J. A. Gomes Neto
Keyword(s):  
Simultaneous Determination ◽  
Sugar Cane ◽  
Fermentation Process ◽  
Chemical Modifier ◽  
Acid Digestion ◽  
Microwave Assisted ◽  
Relative Standard ◽  
Integrated Platform ◽  
Characteristic Mass

A method has been developed for the simultaneous determination of Cd and Pb in antibiotics used in sugar-cane fermentation by GFAAS. The integrated platform of transversely heated graphite atomizer was treated with tungsten to form a coating of tungsten carbide. Six samples of commercial solid antibiotics were analyzed by injecting 20 µL of digested samples into the pretreated graphite platform with co-injection of 5 µL of 1000 mg L-1 Pd as chemical modifier. Samples were mineralized in a closed-vessel microwave-assisted acid-digestion system using nitric acid plus hydrogen peroxide. The pyrolysis and atomization temperatures of the heating program of the atomizer were selected as 600°C and 2200°C, respectively. The calculated characteristic mass for Cd and Pb was 1.6 pg and 42 pg, respectively. Limits of detection (LOD) based on integrated absorbance were 0.02 µg L-1 Cd and 0.7 µg L-1 Pb and the relative standard deviations (n = 10) for Cd and Pb were 5.7% and 8.0%, respectively. The recoveries of Cd and Pb added to the digested samples varied from 91% to 125% (Cd) and 80% to 112% (Pb).

ICP-AES Determination of Mineral Elements in Five Edible Seeds after Microwave Assisted Digestion

2014 ◽  
Vol 881-883 ◽  
pp. 827-830
Author(s):  
Ying Wang ◽  
Qin Chao Ma ◽  
Hao Nan Xu ◽  
Kun Feng ◽  
Yan Tang
Keyword(s):  
Mineral Elements ◽  
Sunflower Seeds ◽  
Acid Digestion ◽  
Microwave Assisted ◽  
Relative Standard ◽  
Edible Seeds ◽  
Pumpkin Seeds ◽  
Melon Seeds ◽  
Microwave Assisted Digestion

The concentrations of 12 elements (Ca, P, K, Na, Mg, Fe, Se, Mn, Zn, Sn, Cu and Al) were determined in raw and roasted pumpkin seeds by ICP-AES following microwave-assisted acid digestion. The accuracy of the method determined by spiking experiments was very good (recoveries 95.48103.2%) and the limits of detection of elements of interest were from 0.1 up to 17.4μg g-1, the relative standard deviations were less than 3.52%. Compared with watermelon seeds, winter melon seeds, sunflower seeds and hanging melon seeds, the results showed the five kinds of roasted melon seeds are all rich in mineral elements.

scholarly journals Reverse phase-liquid chromatography assisted protocol for simultaneous determination of lamivudine and tenofovir disoproxil fumarate in combined medication used to control HIV infection: an investigative approach

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Vaibhav S. Adhao ◽  
Suraj R. Chaudhari ◽  
Jaya P. Ambhore ◽  
Sunil Sangolkar ◽  
Raju R. Thenge ◽  
...  
Keyword(s):  
Liquid Chromatography ◽  
Hiv Infection ◽  
Simultaneous Determination ◽  
Tenofovir Disoproxil Fumarate ◽  
Solvent System ◽  
Array Detector ◽  
Technical Requirements ◽  
Relative Standard ◽  
Limit Of Quantitation

Abstract Background Human immunodeficiency virus (HIV) causes severe life-threatening condition, i.e., AIDS. HIV destabilises an individual’s ability to prevent infection. Therefore, the combine medication lamivudine (LVD) and tenofovir disoproxil fumarate (TDF) are prescribed to suppress the amount of HIV infection in individual’s body; thus, the individual’s immune system could function properly. Consequently, the objective of present research work was to investigate robust and sensitive liquid chromatography avenue for simultaneous determination of lamivudine and tenofovir disoproxil fumarate in pure material and combined dosage form. Results The reversed-phase chromatographic separation has been performed through Hypersil BDS C18 column using solvent system composed of 10 mM potassium dihydrogen phosphate (pH 4.0): acetonitrile (60:40% v/v). The determination was executed at 30 oC at 1 mL/min rate for flow of solvent system through column. The eluents of column were monitored at 265 nm using Photodiode Array detector has revealed admirable retention times, i.e., 4.67 and 8.78 min for both drugs, respectively. The calibration curve demonstrated excellent linearity in the range of 10–50 μg/mL for lamivudine and tenofovir disoproxil fumarate with better determination coefficients was more than (r2 0.999). Conclusion The estimable method was effectively validated with respect to accuracy, precision, sensitive (limit of detection and limit of quantitation), robustness, ruggedness, and for selectivity and specificity. The value less than 2 for percentage relative standard deviation for accuracy, precision, robustness, and ruggedness satisfying the acceptance criteria as per procedure of International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use.

scholarly journals Three Different Spectrophotometric Methods for Simultaneous Determination of Pyriproxyfen and Chlorothalonil Residues in Cucumber and Cabbage Samples

2019 ◽  
Vol 2019 ◽  
pp. 1-11
Author(s):  
Shilan A. Omer ◽  
Nabil A. Fakhre
Keyword(s):  
Simultaneous Determination ◽  
Simultaneous Estimation ◽  
Zero Crossing ◽  
Spectrophotometric Methods ◽  
First Derivative ◽  
The Third ◽  
Mean Centering ◽  
Relative Standard ◽  
One Way Anova

In this study, three simple and accurate spectrophotometric methods for simultaneous determination of pyriproxyfen and chlorothalonil residues in cucumbers and cabbages grown in experimental greenhouse were studied. The first method was based on the zero-crossing technique measurement for first and second derivative spectrophotometry. The second method was based on the first derivative of the ratio spectra. However, the third method was based on mean centering of ratio spectra. These procedures lack any previous separation steps. The calibration curves for three spectrophotometric methods are linear in the concentration range of 1–30 μg·mL−1 and 0.5–7 μg·mL−1 for pyriproxyfen and chlorothalonil successively. The recoveries ranged from 82.12–97.40% for pyriproxyfen and 81.51–97.04% for chlorothalonil with relative standard deviations less than 4.95% and 5.45% in all instances for pyriproxyfen and chlorothalonil, respectively. The results obtained from the proposed methods were compared statistically by using one-way ANOVA, and the results revealed there were no significant differences between ratio spectra and mean centering methods with the zero-crossing technique. The proposed methods are successfully applied for the simultaneous estimation of the residue of both pesticides in cucumber and cabbage samples.

Simultaneous Determination of Four Herbicide and Pesticide Residues in Chinese Green Tea Using QuEChERS Purification Procedure and UPLC-MS/MS Analysis

2013 ◽  
Vol 634-638 ◽  
pp. 1586-1590
Author(s):  
Su Fang Wang ◽  
Shou Jie Zhang ◽  
Chun Hong Dong ◽  
Guo Qing Wang ◽  
Jun Feng Guo ◽  
...  
Keyword(s):  
Formic Acid ◽  
Simultaneous Determination ◽  
Green Tea ◽  
Limit Of Detection ◽  
Multiple Reaction Monitoring ◽  
Graphitized Carbon Black ◽  
Ms Analysis ◽  
Relative Standard ◽  
Limit Of Quantitation

A method for simultaneous determination of residuals of four herbicides and pesticides, simazine, carboxin, diflubenzuron and rotenone, in Chinese green tea was developed. In the proposed method, the tea powder was placed in a centrifuge tube with a plug, extracted in saturated aqueous sodium chloride solution and acetonitrile, agitated using vortex oscillator, and then centrifuged 5 min at 4000 rpm. The supernatant solution was purified by primary secondary amine (PSA) sorbent, C18 power, and graphitized carbon black powder, respectively. Then the purified extracts were dissolved with acetonitrile:0.1% formic acid aqueous solution (40:60, V/V) and agitated, filtered using a syringe with 0.22 μm nylon filter prior to UPLC-MS/MS analysis. The UPLC analysis was performed on an ACQUITY UPLC® HSS T3 column (2.1 mm×100 mm, 1.8 µm), using acetonitrile-0.1% formic acid as mobile phase with the flow rate as 0.3 mL•min-1. Injection volume was 10 µL. Positive ionization mode was applied, and the ions were monitored in the multiple reaction monitoring (MRM) mode with curtain gas 0.069 MPa, collision gas 0.052 MPa, ESI ion spray voltage 5000 V, temperature 550 °C, nebulizer gas 0.24 MPa, and turbo gas 0.28 MPa. The limit of detection (LOD) and limit of quantitation (LOQ) of the proposed method are 1 μg•kg-1and 5 μg•kg-1, respectively. The average recoveries of the four pesticides at 10, 20, and 50 µg•kg-1spiking levels range from 77.4% to 95.3%. TheSupersSuperscript textcript textrelative standard deviation (RSD) (n=6) range form 11.83% to 4.52%.

scholarly journals Simultaneous determination of clobutinol hydrochloride and doxylamine succinate from syrups by RP HPLC using a new stationary phase containing embedded urea polar groups

2012 ◽  
Vol 48 (2) ◽  
pp. 315-323 ◽  
Author(s):  
Paulo Cesar Pires Rosa ◽  
Isabel Cristina Sales Fontes Jardim
Keyword(s):  
Stationary Phase ◽  
Simultaneous Determination ◽  
Reversed Phase ◽  
Hplc Method ◽  
Array Detector ◽  
Polar Groups ◽  
Ich Guidelines ◽  
Relative Standard ◽  
New Stationary Phase

A new, simple, fast, reproducible and sensitive reversed phase HPLC method, using a new stationary phase containing embedded urea polar groups, has been developed and validated for the simultaneous determination of clobutinol hydrochloride (CLO) and doxylamine succinate (DOX) in syrups. The determination was carried out on a C8 urea column (125 mm x 3.9 mm i.d., 5 µm particle size) synthetized at the Liquid Chomatography Laboratory (LabCrom) of the Chemistry Institute of Unicamp. The mobile phase consisted of a mixture of acetonitrile:methanol:phosphate buffer (pH 2.5) in the gradient mode. The diode array detector (DAD) was operated at 230 nm for CLO and 262 nm for DOX. The method showed adequate precision, with relative standard deviations (RSD) less than 1%. The presence of the excipients did not interfere in the results of the analysis. Accuracy was determined by adding standards of the drugs to a placebo and good recovery values were obtained. The analytical curves were linear (r² 0.9999 for CLO and 0.9998 for DOX) over a wide concentration range (2.4-336 µg mL-1 for CLO and 2.3-63 µg mL-1 for DOX). The solutions were stable for at least 72 hours at room temperature. The criteria for validation using the ICH guidelines were fulfilled.

scholarly journals Application of Liquid Chromatography to the Simultaneous Determination of Acetylsalicylic Acid, Caffeine, Codeine, Paracetamol, Pyridoxine, and Thiamine in Pharmaceutical Preparations

2001 ◽  
Vol 84 (3) ◽  
pp. 676-683 ◽  
Author(s):  
Natividad Ramos-Martos ◽  
Francisco Aguirre-Gómez ◽  
Antonio Molina-Díaz ◽  
Luis F Capitán-Vallvey
Keyword(s):  
Salicylic Acid ◽  
Acetylsalicylic Acid ◽  
Simultaneous Determination ◽  
Pharmaceutical Preparations ◽  
Reversed Phase ◽  
Liquid Chromatographic Method ◽  
Relative Standard ◽  
Phase Liquid ◽  
Liquid Chromatographic

Abstract This paper describes a rapid reversed-phase liquid chromatographic method, with UV detection, for the simultaneous determination of acetylsalicylic acid, caffeine, codeine, paracetamol, pyridoxine, and thiamine in pharmaceutical preparations. A reversed-phase C18 Nucleosil column is used. The mobile phase consists of 2 successive eluants: water (5 min) and acetonitrile–water (75 + 25, v/v; 9 min), both adjusted to pH 2.1 with phosphoric acid. Before determination acetylsalicylic acid is completely converted to salicylic acid by alkaline hydrolysis. Salicylic acid, caffeine, paracetamol, pyridoxine, and thiamine are all detected at 285 nm, whereas codeine is detected at 240 nm. Calibration curves were linear for salicylic acid, caffeine, paracetamol, and pyridoxine in the range of 50–500 mg/L, and for codeine and thiamine in the range of 50–1000 mg/L. The method was applied to the analysis of 13 fortified commercial pharmaceutical preparations. Recoveries ranged from 92.6 to 105.5%, with relative standard deviations of 1.1–5.8%.

Simultaneous Determination of Eight New Generation Amide Insecticide Residues in Complex Matrix Agri-food by Multi-walled Carbon Nanotube Cleanup and UPLC-MS/MS

2021 ◽  
Author(s):  
Tao Lin ◽  
Xinglian Chen ◽  
Li Wang ◽  
Haixian Fang ◽  
Maoxuan Li ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Simultaneous Determination ◽  
High Performance ◽  
Rapid Determination ◽  
Complex Matrix ◽  
Limit Of Quantification ◽  
Relative Standard ◽  
The Matrix ◽  
Multi Walled Carbon Nanotubes

Abstract The simultaneous determination method of 8 amide pesticides by multi-walled carbon nanotubes (MWCNs) cleanup, combined with QuEChERS method and ultra-high performance liquid chromatography-triple quadrupole tandem mass spectrometry has been developed and successfully applied in complex matrix such as green onions, celery, leeks, citrus, lychees, avocado. The matric effect of MWCNs is optimized and compared with QuEChERS materials. The results show that MWCNs can effectively reduce the matrix effect in sample extraction. The mass spectrometry is optimized, through their chemical structure skeletons, the ESI+ and ESI- mode are simultaneously scanned in the method. The coefficient (r) is greater than 0.9990, the limit of quantification ranges from 0.03 to 0.80 μg/kg, the recovery rate ranges from 71.2% to 120%, and the relative standard deviation (RSD) ranges from 3.8% to 9.4%. The method is fast, simple, sensitive, and has good purification effect. It is suitable for the rapid determination of amide pesticides in complex matrix agri-food.

scholarly journals Development and Validation of a Reversed-Phase High-Performance Liquid Chromatographic Method for the Simultaneous Determination of Amiloride Hydrochloride, Atenolol, Hydrochlorothiazide, and Chlorthalidone in Their Combined Mixtures

2009 ◽  
Vol 92 (2) ◽  
pp. 404-409 ◽  
Author(s):  
Abdalla A Elshanawane ◽  
Samia M Mostafa ◽  
Mohamed S Elgawish
Keyword(s):  
Simultaneous Determination ◽  
High Performance ◽  
Chromatographic Method ◽  
High Performance Liquid Chromatographic ◽  
Ternary Mixtures ◽  
Liquid Chromatographic Method ◽  
Relative Standard ◽  
Liquid Chromatographic ◽  
Amiloride Hydrochloride

Abstract A high-performance liquid chromatographic method was developed for the simultaneous determination of 2 ternary mixtures containing amiloride hydrochloride, atenolol, hydrochlorothiazide, and chlorthalidone used in hypertension therapy. The use of cyanopropyl column results in satisfactory separation of both mixtures. The mobile phase consisted of 10 mM KH2PO4 buffer (pH 4.5) and methanol in a ratio of (75 25 v/v), at a flow rate of 1 mL/min. UV detector was operated at 275 nm. Calibration graphs were linear in the concentration ranges of 210, 20200, 10100, and 550 g/mL for amiloride hydrochloride, atenolol, hydrochlorothiazide, and chlorthalidone, respectively. Intraday and interday precision values (relative standard deviation) were <1.13 for mixture I (amiloride hydrochloride, atenolol, chlorthalidone), and <0.93 for mixture II (amiloride hydrochloride, atenolol, hydrochlorothiazide). The method was successfully applied for the determination of the 2 combinations in laboratory-prepared mixtures and commercial pharmaceutical formulation with high accuracy and precision. Statistical comparison of the results with those of the published methods showed excellent agreement and indicates no significant difference between them.

scholarly journals Liquid Chromatography–Tandem Mass Spectrometry for the Simultaneous Determination of Doxorubicin and its Metabolites Doxorubicinol, Doxorubicinone, Doxorubicinolone, and 7-Deoxydoxorubicinone in Mouse Plasma

Molecules ◽  
2020 ◽  
Vol 25 (5) ◽  
pp. 1254 ◽  
Author(s):  
Won-Gu Choi ◽  
Dong Kyun Kim ◽  
Yongho Shin ◽  
Ria Park ◽  
Yong-Yeon Cho ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Tandem Mass Spectrometry ◽  
Simultaneous Determination ◽  
Tandem Mass ◽  
Mouse Plasma ◽  
Chromatography Tandem Mass Spectrometry ◽  
Relative Standard ◽  
Liquid Chromatography Tandem Mass

Doxorubicin, an anthracycline antitumor antibiotic, acts as a cancer treatment by interfering with the function of DNA. Herein, liquid chromatography-tandem mass spectrometry was for the first time developed and validated for the simultaneous determination of doxorubicin and its major metabolites doxorubicinol, doxorubicinone, doxorubicinolone, and 7-deoxydoxorubicinone in mouse plasma. The liquid–liquid extraction of a 10 μL mouse plasma sample with chloroform:methanol (4:1, v/v) and use of the selected reaction monitoring mode led to less matrix effect and better sensitivity. The lower limits of quantification levels were 0.5 ng/mL for doxorubicin, 0.1 ng/mL for doxorubicinol, and 0.01 ng/mL for doxorubicinone, doxorubicinolone, and 7-deoxydoxorubicinone. The standard curves were linear over the range of 0.5–200 ng/mL for doxorubicin; 0.1–200 ng/mL for doxorubicinol; and 0.01–50 ng/mL for doxorubicinone, doxorubicinolone, and 7-deoxydoxorubicinone in mouse plasma. The intra and inter-day relative standard deviation and relative errors for doxorubicin and its four metabolites at four quality control concentrations were 0.9–13.6% and –13.0% to 14.9%, respectively. This method was successfully applied to the pharmacokinetic study of doxorubicin and its metabolites after intravenous administration of doxorubicin at a dose of 1.3 mg/kg to female BALB/c nude mice.

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