scholarly journals Miniaturized Fluorimetric Method for Quantification of Zinc in Dry Dog Food

2020 ◽  
Vol 2020 ◽  
pp. 1-6
Author(s):  
Rute C. Martins ◽  
Ana M. Pereira ◽  
Elisabete Matos ◽  
Luisa Barreiros ◽  
António J. M. Fonseca ◽  
...  
Keyword(s):  
Limit Of Detection ◽  
Rapid Determination ◽  
Low Cost ◽  
Food Samples ◽  
Dog Food ◽  
Fluorimetric Assay ◽  
Relative Standard ◽  
The Stability ◽  
Cost Determination

Zinc is an essential trace element for animals in several biological processes, particularly in energy production, and it is acquired from food ingestion. In this context, a microplate-based fluorimetric assay was developed for simple, fast, and low-cost determination of zinc in pet food using 2,2′-((4-(2,7-difluoro-3,6-dihydroxy-4aH-xanthen-9-yl)-3-methoxyphenyl)azanediyl)diacetic acid (FluoZin-1) as fluorescent probe. Several aspects were studied, namely, the stability of the fluorescent product over time, the FluoZin-1 concentration, and the pH of reaction media. The developed methodology provided a limit of detection of 1 μg L−1 in sample acid digests, with a working range of 10 to 200 μg L−1, corresponding to 100–2000 mg of Zn per kg of dry dog food samples. Intraday repeatability and interday repeatability were assessed, with relative standard deviation values < 3.4% (100 μg L−1) and <11.7% (10 μg L−1). Sample analysis indicated that the proposed fluorimetric assay provided results consistent with ICP-MS analysis. These results demonstrated that the developed assay can be used for rapid determination of zinc in dry dog food.

scholarly journals A Low Cost and Simple Lab-on-a-Chip for Spectrophotometric Determination of Ethanol

2017 ◽  
Vol 15 (7) ◽  
pp. 529-539
Author(s):  
Thanyaluck SOMSAENG ◽  
Kem PUMSA-ARD ◽  
Piyada JITTANGPRASERT
Keyword(s):  
Limit Of Detection ◽  
Rapid Determination ◽  
Low Cost ◽  
Colorimetric Detection ◽  
Lab On A Chip ◽  
Ceric Ammonium Nitrate ◽  
Alcoholic Beverages ◽  
Manufacturing Cost ◽  
Relative Standard

A simple lab-on-a-chip system was developed for the rapid determination of ethanol in different sample matrices, including gasohol and various alcoholic beverages. The colorimetric detection of ethanol using a spectrophotometer was based on the reaction between ethanol with 0.12 M ceric ammonium nitrate in acidic medium to produce a red colored product which gave a maximum absorption at 470 nm. A non-lithographic method was used for creating lab-on-a-chip molds to reduce  manufacturing cost and preparation steps. The lab-on-a-chip device was fabricated from polydimethylsiloxane which consisted of a simple Y-shaped working channel. Under optimum conditions, a linear calibration graph was obtained in the concentration range of 0.20 - 20 % (v/v) (r2> 0.999). The limit of detection (3 SD) and limit of quantification (10 SD) were 0.039 and 0.13 % (v/v), respectively. The precision reported in terms of relative standard deviation (RSD) values was less than 1.40 % (n = 15). To demonstrate the lab-on-a-chip’s performance, the determination of ethanol in gasohol and various alcoholic beverages was applied. The results obtained from the developed method compared with a standard gas chromatographic method were well correlated using the paired t-test and linear regression test. The results indicate that the proposed method has shown potential to extend the use of this simple lab-on-a-chip analytical device, due to its simplicity, low cost, lower reagent and sample consumption and high analytical performance. Moreover, the method of fabrication would be an additive manufacturing technique featuring a low equipment cost with no need for clean rooms.

scholarly journals Rapid and Sensitive Spectrophotometric Method for the Determination of the Trace Amount of Thallium (III) in Water and Urine Samples by New Oxidative Coupling Reaction

2019 ◽  
Vol 53 (4) ◽  
Author(s):  
Padmarajaiah Nagaraja ◽  
Naef Ghllab Saeed Al-Tayar ◽  
Anantharaman Shivakumar ◽  
Ashwinee Kumar Shresta ◽  
Avinash K. Gowda
Keyword(s):  
Spectrophotometric Method ◽  
Limit Of Detection ◽  
Rapid Determination ◽  
Coupling Reaction ◽  
Molar Absorptivity ◽  
Urine Samples ◽  
Oxidative Coupling Reaction ◽  
Relative Standard ◽  
Student’S T

A very simple, sensitive and fairly selective direct spectrophotometric method is presented for the rapid determination of thallium(III) at trace level. The method is based on the oxidation of 2-hydrazono-3-methyl-2,3-dihydrobenzo[d]thiazole hydrochloride (MBTH) by thallium(III) in phosphoric acid medium to form a diazoniumcation, which couples immediately with 10,11-dihydro-5Hdibenzo[b,f]azepine (IDB) at room temperature giving a blue colored species having a maximum absorption at 660 nm. The reaction conditions and other important analytical parameters were optimized.The calibration curve was found to be linear over the range of 0.1-4 μg/mL with molar absorptivity of 4.5 × 104 L mol- cm-1 and Sandell’s sensitivity of 0.00454 μg cm-2. The relative standard deviation and limit of detection have been found to be 0.58% and 0.0147 μg/mL respectively. Almost all common anions and cations are found notto interfering in matrix level of the analytical process. The method has been successfully applied for the determination of thallium(III) in synthetic standard mixtures, water and human urine samples. The performance of proposed method was evaluated in terms of student’s t-test and variance ratio F-test, to find out the significance of proposed method over the reported methods.    

Rapid Determination of Fumonisin B1 in Food Samples by a Clean-Up Tandem Immunoassay Column

2012 ◽  
Vol 488-489 ◽  
pp. 1568-1573 ◽  
Author(s):  
Yan Wang ◽  
Guang He Wu ◽  
Wei Sheng ◽  
Yan Zhang ◽  
Meng Yuan ◽  
...  
Keyword(s):  
Limit Of Detection ◽  
Rapid Determination ◽  
Enzymatic Reaction ◽  
Simultaneous Detection ◽  
Fumonisin B1 ◽  
Food Samples ◽  
Promising Tool ◽  
Pre Treatment ◽  
Treatment Procedures

An immunochemistry-based assay for non-instrumental simultaneous detection of fumonisins in food was developed. The method was based upon the direct competitive immuno-reaction and the horse radish peroxidase enzymatic reaction. The assay was developed to show a visual detection result, according to a yes/no response to the LOD of fumonisins. The limit of detection (LOD) was 40 μg L-1. The assay could be accomplished within 15 min in all and 4 min for chromogenic substrate application. The fumonisin contaminations in different kinds of food were analyzed by the proposed method and the results were confirmed by ELISA. Avoiding time-consuming reaction steps and complicated pre-treatment procedures, this assay was demonstrated as a promising tool for on-site sample detections.

scholarly journals Preparation of NiO-graphene oxide nanosensor for adsorptive stripping voltammetric determination of dinoterbon in food samples

2016 ◽  
Vol 6 (3) ◽  
pp. 253
Author(s):  
Kasaram Roja ◽  
Puthalapattu Reddy Prasad ◽  
Punyasamudram Sandhya ◽  
Neelam Yugandhar Sreedhar
Keyword(s):  
Graphene Oxide ◽  
Limit Of Detection ◽  
Stripping Voltammetry ◽  
Pulse Amplitude ◽  
Deposition Potential ◽  
Food Samples ◽  
Adsorptive Stripping Voltammetry ◽  
Relative Standard ◽  
Single Well

<p class="PaperAbstract"><span lang="EN-US">Graphene oxide (GO) modified NiO electrochemical nanosensor was developed for the determination of the dinoterbon in food samples using adsorptive stripping voltammetry. The modified nanosensor characterized by TEM, XRD, cyclic and adsorptive stripping voltammetry. Dinoterbon pesticide exhibited a single well-defined cathodic peak at pH 4.0 at Britton–Robinson buffer (-810.0 mV). The voltammetric characterization of the pesti­cide residues is evaluated and the parameter such as the effect of pH, scan rate, pulse amplitude, deposition potential and deposition time were optimized. The current–concen­tration plot obtained using this peak was straight-lined over the range from 0.05 to 40.00 µg mL<sup>-1 </sup>with limit of detection (LOD) 0.028 µg mL<sup>-1</sup>. The proposed method was efficiently applied to the determination of dinoterbon in food samples. The mean recoveries of the pesticide 97.40 to 99.88 % with a relative standard deviation of 0.114 % in food samples respectively.</span></p>

A rapid in vitro assay of cobalamin in human urine and medical tablets using ICP-MS

2009 ◽  
Vol 63 (3) ◽  
Author(s):  
Gai Zhang ◽  
Jianbo Liu ◽  
Zuchao Meng ◽  
Xin Wang
Keyword(s):  
Human Urine ◽  
Inductively Coupled Plasma ◽  
Limit Of Detection ◽  
Rapid Determination ◽  
Vitro Assay ◽  
Cobalt Ions ◽  
Icp Ms ◽  
Relative Standard

AbstractA rapid and simple as well as sensitive inductively coupled plasma mass spectrometry (ICP-MS) method for the determination of cobalamin is described. Cobalamin in human urine and medicine tablet solutions was converted on-line into free cobalt ions in acid medium, the cobalt ions were then detected by ICP-MS. Cobalamin was determined by measuring the increase of integral counts per second intensity, which was linear over the cobalamin concentration range of 1.0 × 10−10 g mL−1 to 8.0 × 10−5 g mL−1, and the limit of detection was 0.05 ng mL−1 (3σ). At the pump rate of 30 rotations per minute, one analysis cycle of cobalamin, including sampling and washing, could be accomplished in 0.5 min with the relative standard deviations of less than 5 %. The proposed procedure was applied successfully in monitoring cobalamin in human urine without any pretreatment process and in rapid determination of cobalamin in multivitamin tablets.

Rapid determination of fosetyl-aluminium in commercial pesticide formulations by high-performance liquid chromatography

2014 ◽  
Vol 68 (6) ◽  
Author(s):  
Helen Karasali ◽  
Konstantinos Kasiotis ◽  
Kyriaki Machera
Keyword(s):  
Standard Deviation ◽  
Relative Standard Deviation ◽  
High Performance ◽  
Limit Of Detection ◽  
Rapid Determination ◽  
Hplc Method ◽  
Negative Ion ◽  
Rp Hplc ◽  
Relative Standard

AbstractAn isocratic reversed-phase high-performance liquid chromatographic (RP-HPLC) method with diode array detection (DAD) was developed for the determination of aluminium tris(ethyl phosphonate) (fosetyl-aluminium, fosetyl-Al) in plant-protection products. The method involves extraction of the active ingredient by sonication of the sample with water and direct measurement by RPHPLC. The isocratic RP-HPLC method for the analysis of fosetyl-Al thus developed was then validated for specificity, linearity, precision, and accuracy. The chromatographic peak confirmation was performed by LC-MS using electron spray ionisation in the negative-ion mode. The repeatability of the method, expressed as relative standard deviation (RSD, %), was found to be 0.5 % and the limit of detection was 0.035 mg mL−1. The average recoveries of the three fortification levels varied from 96.7 % to 100.6 % and the RSDs ranged between 2.6 % and 6.3 %. The precision of the method was also considered to be acceptable as the experimental repeatability relative standard deviation (RSDr) was lower than the RSDr, calculated using the Horwitz equation. The method is rapid, simple, accurate, cost-effective, and provides a new and reliable means for the analysis of fosetyl-Al in formulated products.

scholarly journals Determination of four naphthalenediols in cosmetic samples by sweeping-micellar electrokinetic chromatography and a comparison with HPLC

2021 ◽  
Author(s):  
Qian Wang ◽  
Xiaobin Li ◽  
Zhihan Zheng ◽  
Huitao Liu ◽  
Yuan Gao
Keyword(s):  
Micellar Electrokinetic Chromatography ◽  
Limit Of Detection ◽  
Low Cost ◽  
Hplc Method ◽  
National Standards ◽  
Sample Introduction ◽  
Electrokinetic Chromatography ◽  
Relative Standard ◽  
Limit Of Quantitation

Abstract A sweeping micellar electrokinetic chromatography (sweeping-MEKC) method was developed for the determination of 1,7-naphthalenediol, 2,3-naphthalenediol, 1,5-naphthalenediol and 2,7-naphthalenediol in cosmetics. Several parameters affecting sweeping-MEKC method were studied systematically and the separation conditions were optimized as 20 mM NaH2PO4–110 mM SDS and 40% (v/v) MeOH (pH 2.4), with −22 kV applied voltage and UV detection at 230 nm. The sample matrix is 60 mmol L−1 NaH2PO4 and sample introduction was performed at 3 psi for 6 s. Separation of the four naphthalenediols was completed in less than 17 min. Limit of detection (LOD) and limit of quantitation (LOQ) are 0.0045∼0.0094 μg mL−1 and 0.015∼0.031 μg mL−1. Linear relationship (r 2 > 0.999) is satisfactory at the range of 0.1–10 μg mL−1. The developed method has been successfully applied to the determination of the four naphthalenediols in real cosmetic samples, with recoveries in foundation, sun cream and lotion in the range of 92.3%∼106.8% and relative standard deviation (RSD) less than 4.15%. A HPLC method described in the National Standards of the People’s Republic of China was carried out for the comparison with the proposed method. The results showed that the proposed sweeping-MEKC method has the advantages of fast, low cost with comparative sensitivity.

scholarly journals Preparation of NiO-graphene oxide nanosensor for adsorptive stripping voltammetric determination of dinoterbon in food samples

2016 ◽  
Vol 6 (3) ◽  
pp. 253
Author(s):  
Kasaram Roja ◽  
Puthalapattu Reddy Prasad ◽  
Punyasamudram Sandhya ◽  
Neelam Yugandhar Sreedhar
Keyword(s):  
Graphene Oxide ◽  
Limit Of Detection ◽  
Stripping Voltammetry ◽  
Pulse Amplitude ◽  
Deposition Potential ◽  
Food Samples ◽  
Adsorptive Stripping Voltammetry ◽  
Relative Standard ◽  
Single Well

<p class="PaperAbstract"><span lang="EN-US">Graphene oxide (GO) modified NiO electrochemical nanosensor was developed for the determination of the dinoterbon in food samples using adsorptive stripping voltammetry. The modified nanosensor characterized by TEM, XRD, cyclic and adsorptive stripping voltammetry. Dinoterbon pesticide exhibited a single well-defined cathodic peak at pH 4.0 at Britton–Robinson buffer (-810.0 mV). The voltammetric characterization of the pesti­cide residues is evaluated and the parameter such as the effect of pH, scan rate, pulse amplitude, deposition potential and deposition time were optimized. The current–concen­tration plot obtained using this peak was straight-lined over the range from 0.05 to 50.00 µg mL<sup>-1 </sup>with limit of detection (LOD) 0.028 µg mL<sup>-1</sup>. The proposed method was efficiently applied to the determination of dinoterbon in food samples. The mean recoveries of the pesticide 97.40 to 99.88 % with a relative standard deviation of 0.114 % in food samples respectively.</span></p><br /><p><strong> </strong></p>

scholarly journals DEVELOPMENT AND VALIDATION OF NEW RP-UPLC METHOD FOR THE DETERMINATION OF CEFDINIR IN BULK AND DOSAGE FORM

2018 ◽  
Vol 10 (1) ◽  
pp. 178
Author(s):  
Krishnaphanisri Ponnekanti ◽  
Raja Sundararajan
Keyword(s):  
Mobile Phase ◽  
Limit Of Detection ◽  
Detection Limits ◽  
Thermal Conditions ◽  
Forced Degradation ◽  
Column Temperature ◽  
Relative Standard ◽  
Bulk Drug ◽  
The Stability

Objective: The objective of the study was to develop and validate a new rapid and sensitive reverse phase ultra-performance liquid chromatographic (RP-UPLC) method for determination of cefdinir in bulk drug and dosage form.Methods: Separation was achieved with an Acquity SB C18 (100 × 2 mm) 1.8μm column with an isocratic mobile phase containing a mixture of orthophosphoric acid and acetonitrile (60:40 v/v) and pH adjusted to 2.8. The flow rate of the mobile phase was 0.3 ml/min with a column temperature of 30 °C and detection wavelength at 285 nm.Results: The method was validated with respect to linearity, accuracy, precision, detection limits, robustness and specificity. The precision of the results, stated as the relative standard deviation was below 1.5%. The calibration curve was linear over a concentration range from 25 to 150μg/ml with a correlation coefficient of 0.9993. The accuracy of the method demonstrated at three levels in the range of 50%, 100% and 150% of the specification limit. The recovery of cefdinir was found to be in the range of 98 to 102%, whereas the detection limits were found to be 0.17 and 0.51µg/ml. Forced degradation study was carried out under acidic, alkaline, oxidative, photolytic and thermal conditions to prove the stability-indicating ability of the developed UPLC method.Conclusion: The developed method was validated with respect to linearity, accuracy, precision limit of detection and quantification, robustness and specificity. The method was applied successfully for the determination of cefdinir in tablets.

Rapid Determination of Total Cholesterol in Homogenized Milk

1989 ◽  
Vol 72 (3) ◽  
pp. 421-424 ◽  
Author(s):  
Ida C Tsui
Keyword(s):  
Total Cholesterol ◽  
Limit Of Detection ◽  
Solid Phase ◽  
Rapid Determination ◽  
Internal Standard ◽  
Gas Chromatograph ◽  
Relative Standard ◽  
Aoac Method ◽  
Normal Work

Abstract A rapid method that is amenable to automation has been developed for the determination of total cholesterol in homogenized milk. The milk sample is saponified in ethanolic KOH in the presence of an internal standard, cholestane. Cholesterol and the internal standard are then isolated by solid-phase extraction on a nonpolar adsorbent and eluted with organic solvent. The evaporated extract is derivatized and analyzed by capillary gas chromatography. Average recovery of cholesterol acetate added to milk prior to saponification was 95%. The average relative standard deviation for repeated analyses was 2%. The limit of detection for this method is 2 mg/100 g. Twenty samples can be analyzed by one analyst in a normal work day if the gas chromatograph is equipped with an autosampler. This method has been compared with a modified AOAC method for the determination of total cholesterol. At a confidence level of 95%, no difference was observed between the 2 methods.

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