scholarly journals Fast and sensitive method for phosphorus determination in dairy products

Author(s):  
Anna Gliszczyńska-Świgło ◽  
Iga Rybicka

AbstractThe spectrophotometric molybdenum blue method for phosphorus determination was adapted to a multiwell plate format. The method was sensitive and allowed for the simultaneous determination of phosphorus in many samples. It was cheap and eco-friendly due to application of small volumes of reagents and, therefore, it meets the requirements for “green” or sustainable chemistry. The method’s limit of detection (LOD) is 0.37 μg/mL and its limit of quantification (LOQ) is 1.13 μg/mL. Its linearity is up to 30 μg of phosphorus/mL. The method was applied for the determination of phosphorus in 65 dairy products (yogurts, yogurt drinks, buttermilks, kefirs and homogenized cheeses) of strawberry, peach, forest fruits, vanilla and other flavours. The phosphorus content was 143–226 mg/100 g in flavoured yogurts, 78–204 mg/100 g in yogurt drinks, 89–218 mg/100 g in kefirs, around 195 mg/100 g in buttermilks, and 165–277 mg/100 g in homogenized cheeses. The presented method can be used in the routine quantitative analysis of the total phosphorus content in dairy products.

2018 ◽  
Vol 2018 ◽  
pp. 1-5 ◽  
Author(s):  
Ahmed Salem Sebaei ◽  
Ahmed M. Gomaa ◽  
A. A. El-Zwahry ◽  
E. A. Emara

Formaldehyde is one of the most dangerous chemical compounds affecting the human health; exposure to it from food may occur naturally or by intentional addition. In this study a high performance liquid chromatography method for determination of formaldehyde in dairy products was described. The dairy samples were reacted and extracted with a warmed organic solvent in the presence of derivatizing agent 2,4-dinitrophenylhydrazine (DNPH) and formaldehyde; the mixture was centrifuged and followed by diode array detection. The method is validated and gives average recovery of formaldehyde at the three different levels 0.1, 5.0, and 10.0 mg/kg varied between 89% and 96%. The method is linear from the limit of quantification 0.1 mg/kg up to 10 mg/kg levels. This method is intended for formaldehyde analyses in dairy products simply with stable derivatization, minimum residue loss, excellent recovery, and accurate results with a sensitive limit of detection 0.01 mg/kg. 90 dairy samples from milk, cheese, and yogurt were investigated from seven Egyptian governorates and all samples were free from formaldehyde.


1964 ◽  
Vol 47 (4) ◽  
pp. 645-651
Author(s):  
W A Steller ◽  
A X Curry

Abstract A total phosphorus method incorporating thin-layer chromatographic isolation is described for the determination of Cygon Insecticide (generic name, dimethoate) and its oxygen analog. Residues of the insecticides are extracted from macerated plant tissue, and the extract, after solvent partitioning and concentration, is spotted on a thin-layer chromatographic plate. After development of the plate, the areas corresponding to the two compounds are scraped and eluted. The phosphorus content of the respective eluates is determined by an improved molybdenum blue method, and concentrations of dimethoate and its oxygen analog in the original samples are calculated.


2015 ◽  
Vol 7 (23) ◽  
pp. 9825-9834 ◽  
Author(s):  
Slobodan V. Jovanovic ◽  
Thomas Zakharov ◽  
Hemendra Mulye ◽  
Duck Kim ◽  
Kelly-Anne Fagan

In this study, we developed and validated a sensitive method for the determination of hydrazine in water samples using ion chromatography coupled with an amperometric detector (limit of detection (LOD) = 0.02 μg L−1 and limit of quantification (LOQ) = 0.1 μg L−1).


Foods ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 2445
Author(s):  
Jin-Man Kim ◽  
Jong-Ho Koh ◽  
Jung-Min Park

Steviol glycosides are used in food and beverages worldwide as natural sweeteners, serving as a low-calorie sugar substitute. The acceptable daily intake of steviol is 0–4 mg/kg body weight. The rising demand for dairy products has led to a corresponding increase in the use of steviol glycosides in such products. Therefore, it is important to analyze the levels of steviol glycosides in dairy products. Dairy products have high fat contents and unique emulsion characteristics, conferred by a mixture of fat globules, casein micelles, whey proteins, and numerous other small molecules. These characteristics may interfere with the estimation of steviol glycoside levels; therefore, dairy samples require pretreatment. We aimed to develop an objective test for measuring the levels of steviol glycosides through the development of an efficient pretreatment method. In this study, the steviol glycoside content in dairy products was evaluated by using various methods, and an optimal pretreatment method was determined. We used high-performance liquid chromatography to assess the selectivity, linearity, limit of detection, limit of quantification, accuracy, precision, and recovery rate. Calibration curves were linear in the range of 1–50 mg/kg, with a coefficient of determination of ≥0.999. The limit of detection and limit of quantification were in the ranges of 0.11–0.56 and 0.33–1.69 mg/kg, respectively. The relative standard deviation (%) represents the precision of a measurement. The RSD relative standard deviationof recovery varied between 0.16% and 2.83%, and recovery of the analysis varied between 83.57% and 104.84%. These results demonstrate the reliability of the method for measuring the steviol glycoside content. This method can be used for the simple pretreatment of steviol glycosides and can provide an accurate determination of steviol glycoside content in emulsified food matrices, such as dairy products.


2021 ◽  
Vol 21 (5) ◽  
pp. 1271
Author(s):  
Nguyen Quoc Thang ◽  
Tran Nguyen Minh An ◽  
Le Thi Thanh Tran ◽  
Do Tam Nhan ◽  
Mai Ngoc Tan ◽  
...  

In this study, the complex of difluoroboron, curcumin (BF2-Cur), has been synthesized and characterized via the combination of Boron trifluoride-diethyl etherate ((C2H5)2OBF3) and curcumin. However, the new dissociation constants, pKa1 and pKa2 of the BF2-Cur complex, have been indicted by the values of 8.44 ± 0.16 and 9.76 ± 0.13, respectively. On the other hand, the reagent was also used to determine As(III) in aqueous solutions by UV–Vis spectrophotometry. As a result, the method was validated for accuracy, precision, linearity, and sensitivity, and the linear range was from 1.0 to 25.0 µmol/L, with the linear regression, A = 0.0027 C + 0.0106, correlation coefficient R2 = 0.9969. Besides, the limit of detection (LOD) and limit of quantification (LOQ) were determined as 0.83 and 2.10 µmol/L, respectively. Thus, the developed method is successfully used for quantitative analysis of total arsenic in wastewater by reducing As(V) to As(III), then determining As(III) with high accuracy results.


Author(s):  
Mohammad Hamzah Hamzah ◽  
Rawa M M Taqi ◽  
Muna M. Hasan ◽  
Raid J. M. Al-Timimi

A simple and accurate spectrophotometric method for the determination of Trifluoperazine HCl in pure and dosage forms was developed. The method is based on the reaction between Trifluoperazine HCl and p-chloroaniline in the presence of cerium ion as oxidizing agent which lead to the formation of violate color product that absorbed at a maximum wavelength 570nm while the blank solution was pink. Under the optimum conditions a linear relationship between the intensity and concentration of TRF in the range 4-50μg/ml was obtained . The molar absorptivity 3.74×103 L.mol-1.cm-1 , Limit of detection (2.21μg/ml), while limit of quantification was 7.39μg/ml. The proposed analytical method was compared with standard method using t-test and F-test , the obtained results shows there is no significant differences between proposed method and standard method. Based on that the proposed method can be used as an alternative method for the determination of TRF in pure and dosage forms.


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Indhu Priya Mabbu ◽  
G. Sumathi ◽  
N. Devanna

Abstract Background The aim of the present method is to develop and validate a specific, sensitive, precise, and accurate liquid chromatography-mass spectrometry (LC-MS) method for the estimation of the phenyl vinyl sulfone in the eletriptan hydrobromide. The effective separation of the phenyl vinyl sulfone was achieved by the Symmetry C18 (50 × 4.6 mm, 3.5 μm) column and a mobile phase composition of 0.1%v/v ammonia buffer to methanol (5:95 v/v), using 0.45 ml/min flow rate and 20 μl of injection volume, with methanol used as diluent. The phenyl vinyl sulfone was monitored on atomic pressure chemical ionization mode mass spectrometer with positive polarity mode. Results The retention time of phenyl vinyl sulfone was found at 2.13 min. The limit of detection (LOD) and limit of quantification (LOQ) were observed at 1.43 ppm and 4.77 ppm concentration respectively; the linear range was found in the concentration ranges from 4.77 to 27.00 ppm with regression coefficient of 0.9990 and accuracy in the range of 97.50–102.10%. The percentage relative standard deviation (% RSD) for six replicates said to be injections were less than 10%. Conclusion The proposed method was validated successfully as per ICH guidelines. Hence, this is employed for the determination of phenyl vinyl sulfone in the eletriptan hydrobromide.


Author(s):  
Kamran Ashraf ◽  
Syed Adnan Ali Shah ◽  
Mohd Mujeeb

<p><strong>Objective: </strong>A simple, sensitive, precise, and accurate stability indicating HPTLC (high-performance thin-layer chromatography) method for analysis of 10-gingerol in ginger has been developed and validated as perICH guidelines.</p><p><strong>Methods: </strong>The separation was achieved on TLC (thin layer chromatography) aluminum plates pre-coated with silica gel 60F<sub>254</sub> using n-hexane: ethyl acetate 55:45 (%, v/v) as a mobile phase. Densitometric analysis was performed at 569 nm.</p><p><strong>Results: </strong>This system was found to have a compact spot of 10-gingerol at <em>R</em><sub>F</sub> value of 0.57±0.03. For the proposed procedure, linearity (<em>r</em><sup>2</sup> = 0.998±0.02), limit of detection (18ng/spot), limit of quantification (42 ng/spot), recovery (ranging from 98.35%–100.68%), were found to be satisfactory.</p><p><strong>Conclusion: </strong>Statistical analysis reveals that the content of 10-gingerol in different geographical region varied significantly. The highest and lowest concentration of 10-gingerol in ginger was found to be present in a sample of Patna, Lucknow and Surat respectively which inferred that the variety of ginger found in Patna, Lucknow are much superior to other regions of India.</p>


2010 ◽  
Vol 7 (3) ◽  
pp. 807-812 ◽  
Author(s):  
Vanita Somasekhar ◽  
D. Gowri Sankar

A reverse phase HPLC method is described for the determination of esmolol hydrochloride in bulk and injections. Chromatography was carried on a C18column using a mixture of acetonitrile, 0.05 M sodium acetate buffer and glacial acetic acid (35:65:3 v/v/v) as the mobile phase at a flow rate of 1 mL/min with detection at 275 nm. The retention time of the drug was 4.76 min. The detector response was linear in the concentration of 1-50 μg/mL. The limit of detection and limit of quantification was 0.614 and 1.86 μg/mL respectively. The method was validated by determining its sensitivity, linearity, accuracy and precision. The proposed method is simple, economical, fast, accurate and precise and hence can be applied for routine quality control of esmolol hydrochloride in bulk and injections.


2012 ◽  
Vol 2012 ◽  
pp. 1-6
Author(s):  
S. N. Prashanth ◽  
Shankara S. Kalanur ◽  
Nagappa L. Teradal ◽  
J. Seetharamappa

The electrochemical behavior of isothipendyl hydrochloride (IPH) was investigated at bare and multiwalled-carbon-nanotube modified glassy carbon electrode (MWCNT-GCE). IPH (55 μM) showed two oxidation peaks in Britton-Robinson (BR) buffer of pH 7.0. The oxidation process of IPH was observed to be irreversible over the pH range of 2.5–9.0. The influence of pH, scan rate, and concentration of the drug on anodic peak was studied. A differential pulse voltammetric method with good precision and accuracy was developed for the determination of IPH in pure and biological fluids. The peak current was found to be linearly dependent on the concentration of IPH in the range of 1.25–55 μM. The values of limit of detection and limit of quantification were noticed to be 0.284 and 0.949 μM, respectively.


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