A high sensitivity, low volume HPLC method to determine soluble reactive phosphate in freshwater and saltwater

2003 ◽  
Vol 82 (3-4) ◽  
pp. 185-196 ◽  
Author(s):  
Jaime L Haberer ◽  
Jay A Brandes
2020 ◽  
Vol 23 (10) ◽  
pp. 1010-1022
Author(s):  
Emrah Dural

Aim and scope: Due to the serious toxicological risks and their widespread use, quantitative determination of phthalates in cosmetic products have importance for public health. The aim of this study was to develop a validated simple, rapid and reliable high-performance liquid chromatography (HPLC) method for the determination of phthalates which are; dimethyl phthalate (DMP), diethyl phthalate (DEP), benzyl butyl phthalate (BBP), di-n-butyl phthalate (DBP), di(2- ethylhexyl) phthalate (DEHP), in cosmetic products and to investigate these phthalate (PHT) levels in 48 cosmetic products marketing in Sivas, Turkey. Materials and Methods: Separation was achieved by a reverse-phase ACE-5 C18 column (4.6 x 250 mm, 5.0 μm). As the mobile phase, 5 mM KH2PO4 and acetonitrile were used gradiently at 1.5 ml min-1. All PHT esters were detected at 230 nm and the run time was taking 21 minutes. Results: This method showed the high sensitivity value the limit of quantification (LOQ) values for which are below 0.64 μg mL-1 of all phthalates. Method linearity was ≥0.999 (r2). Accuracy and precision values of all phthalates were calculated between (-6.5) and 6.6 (RE%) and ≤6.2 (RSD%), respectively. Average recovery was between 94.8% and 99.6%. Forty-eight samples used for both babies and adults were successfully analyzed by the developed method. Results have shown that, DMP (340.7 μg mL-1 ±323.7), DEP (1852.1 μg mL-1 ± 2192.0), and DBP (691.3 μg mL-1 ± 1378.5) were used highly in nail polish, fragrance and cream products, respectively. Conclusion: Phthalate esters, which are mostly detected in the content of fragrance, cream and nail polish products and our research in general, are DEP (1852.1 μg mL-1 ± 2192.0), DBP (691.3 μg mL-1 ± 1378.5) and DMP (340.7 μg mL-1 ±323.7), respectively. Phthalates were found in the content of all 48 cosmetic products examined, and the most detected phthalates in general average were DEP (581.7 μg mL-1 + 1405.2) with a rate of 79.2%. The unexpectedly high phthalate content in the examined cosmetic products revealed a great risk of these products on human health. The developed method is a simple, sensitive, reliable and economical alternative for the determination of phthalates in the content of cosmetic products, it can be used to identify phthalate esters in different products after some modifications.


2017 ◽  
Vol 1064 ◽  
pp. 7-13 ◽  
Author(s):  
Philip A. Waghorn ◽  
Bruno L. Oliveira ◽  
Chloe M. Jones ◽  
Andrew M. Tager ◽  
Peter Caravan
Keyword(s):  

Molecules ◽  
2018 ◽  
Vol 24 (1) ◽  
pp. 95 ◽  
Author(s):  
Shuangjiao Xu ◽  
Kehai Zhou ◽  
Dan Fang ◽  
Lei Ma

In this paper, fluorescent copper nanoclusters (NCs) are used as a novel probe for the sensitive detection of gossypol for the first time. Based on a fluorescence quenching mechanism induced by interactions between bovine serum albumin (BSA) and gossypol, fluorescent BSA-Cu NCs were seen to exhibit a high sensitivity to gossypol in the range of 0.1–100 µM. The detection limit for gossypol is 25 nM at a signal-to-noise ratio of three, which is approximately 35 times lower than the acceptable limit (0.9 µM) defined by the US Food and Drug Administration for cottonseed products. Moreover, the proposed method for gossypol displays excellent selectivity over many common interfering species. We also demonstrate the application of the present method to the measurement of several real samples with satisfactory recoveries, and the results agree well with those obtained using the high-performance liquid chromatography (HPLC) method. The method based on Cu NCs offers the followings advantages: simplicity of design, facile preparation of nanomaterials, and low experimental cost.


Author(s):  
Zubaidur Rahman ◽  
Vijey Aanandhi M ◽  
Sumithra M

Objective: A simple, novel, sensitive, rapid high-performance liquid chromatographic (RP-HPLC) method has been developed and validated for quantitative determination of atomoxetine HCl (ATH) in bulk and formulations.Methods: The chromatographic development was carried out on RP-HPLC. The column used as Xterra RP 18 (250 mm × 4.6 mm, 5 μ particle size), with mobile phase consisting of methanol: water 80:20 V/V. The flow rate was 1.0 mL/min and the effluents were monitored at 270 nm.Results: The retention time was found to be 5.350 min. The method was validated as per International Conference on Harmonization Guideline with respect to linearity, accuracy, precision, and robustness. The calibration curve was found to be linear over a range of 2–10 μg/mL with a regression coefficient of 0.9999. The method has proved high sensitivity and specificity.Conclusion: The results of the study showed that the proposed RP-HPLC method was simple, rapid, precise and accurate which is useful for the routine determination of ATH in bulk drug and in its pharmaceutical dosage form.


2020 ◽  
Vol 58 (9) ◽  
pp. 789-795
Author(s):  
Amira M El-Kosasy ◽  
Lobna A Hussein ◽  
Nesma M Mohamed ◽  
Nahla N Salama

Abstract A simple, precise, rapid and accurate reversed-phase high-performance liquid chromatography (RP-HPLC) method was developed and validated for analysis of safinamide mesylate (SAF) in presence of its basic degradate, and co-administered drugs levodopa and ondansetron. The mobile phase consisted of acetonitrile and 20 mM potassium dihyrogen orthophosphate buffer having pH = 5 (40: 60 v/v). Quantification was achieved with ultraviolet detector at 226 nm. The linear range was 0.5–10 μg/mL with mean recovery ± SD of 99.72 ± 1.59. The peak purity of SAF in pharmaceutical preparation spiked with its degradate and co-administered drugs revealed symmetry factor (999.8) within the calculated threshold (>998.1). The suggested method was validated in compliance with the International Conference on Harmonization (ICH) guidelines and statistically compared with the manufacturer HPLC method with no significant difference in terms of accuracy and precision. The assay method was successfully used to estimate SAF in tablets with good percentage recoveries. The high sensitivity (lower than Cmax of the drug 0.65 μg/mL) of the proposed HPLC method enabled the determination of SAF in presence of its basic degradate and co-administered drug, ondansetron in human plasma with acceptable accuracy. The suggested HPLC method could be used in Quality Control (QC) lab for analysis of the studied drug in pharmaceutical preparation.


Materials ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 2924 ◽  
Author(s):  
Samar Ezzat ◽  
Mona A. Ahmed ◽  
Abd El-Galil E. Amr ◽  
Mohamed A. Al-Omar ◽  
Ayman H. Kamel ◽  
...  

A novel single-piece all-solid-state ion-selective electrode (SC/ISE) based on carbon-screen printed is introduced. Polyaniline (PANI) is dissolved in a membrane cocktail that contains the same components used for making a conventional ion-selective polyvinyl chloride (PVC) matrix membrane. The membrane, having the PANI, is directly drop-casted on a carbon substrate (screen-printed-carbon electrode). PANI was added to act as an intermediary between the substrate and the membrane for the charge transfer process. Under non-equilibrium sensing mechanism, the sensors revealed high sensitivity towards 2,4-dichlorophenol (DCP) over the linearity range 0.47 to 13 µM and a detection limit 0.13 µm. The selectivity was measured by the modified separate solution method (MSSM) and showed good selectivity towards 2,4-DCP over the most commonly studied ions. All measurements were done in 30 mm Tris buffer solution at a pH 5.0. Using constant-current chronopotentiometry, the potential drift for the proposed electrodes was checked. Improvement in the potential stability of the SPE was observed after the addition of PANI in the sensing membrane as compared to the corresponding coated-wire electrode (membrane without PANI). The applicability of the sensor has been checked by measuring 2,4-DCP in different water samples and the results were compared with the standard HPLC method.


2010 ◽  
Vol 93 (5) ◽  
pp. 1503-1514 ◽  
Author(s):  
Sumita Dixit ◽  
Subhash K Khanna ◽  
Mukul Das

Abstract A simple and sensitive HPLC method has been developed for the simultaneous determination of eight permitted food colors and five commonly encountered nonpermitted colors in various food commodities, including sugar-, fat-, and starch-based food matrixes. The method uses a specific food category-based cleanup/treatment procedure before color extraction to avoid the interference of food matrixes, and to obtain the optimal color extraction. Analysis was performed on a reversed-phase C18 -Bondapak column with ammonium acetate and acetonitrile gradient elution as the mobile phase; a programmable max-specific visible detection was used to monitor colors to obtain the higher sensitivity and expanded scope needed for multicolor blends having diverse absorption maxima. All colors showed good linearity, with regression coefficients of 0.99740.9999. The LOD and LOQ values ranged from 0.01 to 0.12 mg/L, and from 0.04 to 0.83 mg/L or mg/kg, respectively. The intraday and interday precision tests produced good RSD values, and the recoveries from different food matrixes ranged from 82 to 104%. The method offers high sensitivity for analysis of a wide variety of food matrixes containing a broad scope of multicolor blends. Two nonpermitted colors, orange II and metanil yellow, were found. Also, a number of samples contained permitted colors at levels two-to seven-fold higher than those prescribed.


1993 ◽  
Vol 28 (1) ◽  
pp. 16-24 ◽  
Author(s):  
R. Vieira ◽  
M. Aldegunde

The determination of serotonin (5-HT), N-acetylserotonin (NAS) and 5-hydroxy-3-indoleacetic acid (5-HIAA) in single brains of two acridids (Paracinema tricolor and Oedipoda caerulescens) was accomplished using a HPLC method combined with amperometric detection. A hydrodynamic voltammetry approach was used to assess the identity of each peak by comparing the voltammograms of standards and those of samples. The analytical method gave satisfactory reproducibility and sensitivity, and detected levels of 5-HT, NAS and 5-HIAA as low as 29, 55 and 10 fmol, respectively. This high sensitivity together with the simplicity of sample processing make the present analytical method suitable for a wide range of studies concerning indoleamine analyses in the insect nervous system. In both acridids, 5-HT showed the largest quantities, while its derivatives occurred in extremely low amounts. The results suggest that N-acetylation of 5-HT is quantitatively preferred to oxidative deamination in both species (NAS levels were 4-fold those of 5-HIAA). The relative importance of each catabolic pathway is discussed as related to physiological and genetic aspects.


2020 ◽  
Vol 11 (4) ◽  
pp. 6793-6799
Author(s):  
Birendra Shrivastava ◽  
Sai Rajesh Kollapudi ◽  
Dinakar A

Cinacalcet (INN), a calcium mimetic drug that mimics the activity of calcium in the body. It expresses itself by activation of calcium-sensing receptor allosterically in different organs and tissues. The secretion of parathyroid hormone is regulated principally by calcium-sensing receptors that are present on the surface of the parathyroid gland. Cinacalcet is used in the treatment of hyperparathyroidism, which is the usual consequence of parathyroid cancers and CKF. There had been a rapid increase in the number of drugs that are adding to each class of drugs. These drugs are formulated into newer formulations either in a single or multi-drug dosage forms. These newer marketed formulations demand a new investigation for the estimation of the drug in the formulations. The existing analytical techniques for those drugs are available in the research literature, but not all the methods are stable and economical to use. The objective of this work was to develop an analytical RP-HPLC method for the estimation of cinacalcet in bulk and tablet formulation. The emphasis was given to the short time of analysis, and simplicity in the method. RP-HPLC analysis of the drug satisfies the peak integrity, suitability, recovery of the drug. LOQ and LOD of the drug were achieved with high sensitivity. The data shows the precision of the method and the accuracy of the method. Overall, the data suggest that the proposed analytical method can be used to analyse the drug in the formulation. This method can be recommended for the routine analysis of the drug in its dosage form.


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