scholarly journals Biogenic Amine Production in Olomouc Curd Cheese (Olomoucké tvarůžky) at Various Storage Conditions

2010 ◽  
Vol 79 (1) ◽  
pp. 147-156 ◽  
Author(s):  
Eva Standarová ◽  
Lenka Vorlová ◽  
Pavlína Kordiovská ◽  
Bohumíra Janštová ◽  
Michaela Dračková ◽  
...  
Keyword(s):  
Storage Time ◽  
Chemical Properties ◽  
Storage Conditions ◽  
Hplc Method ◽  
Sensory Characteristics ◽  
National Standard ◽  
Array Detector ◽  
Low Concentrations ◽  
Photodiode Array Detector ◽  
Physical And Chemical

The aim of this study was to evaluate the effects of temperature and storage time on the formation of biogenic amines (BAs) in the traditional Czech curd cheese (Olomoucké tvarůžky). Samples were stored for 7 weeks at 5 °C and 20 °C. BAs were studied as dansyl derivatives by the RP-HPLC method with fluorescence detection, histamine was determined using a photodiode array detector. Physical and chemical properties were analyzed as specified by the Czech National Standard, as were the sensory characteristics (colour, odour, texture and flavour). The major amines found were cadaverine (124–2413 mg kg-1) and tyramine (117–1058 mg kg-1), followed by putrescine (75–767 mg kg-1) and histamine (74–411 mg kg-1). Low concentrations of tryptamine, spermine and spermidine were present. Total concentrations of BAs significantly increased with storage time (P < 0.01), depending significantly on temperature (P < 0.01). Total BAs in cheese stored at 20 °C compared to 5 °C were more than three times higher, reaching 4600 mg kg-1 at the end of storage. The toxicologically critical value of 900 mg kg-1 for the sum of histamine + tyramine + putrescine + cadaverine was reached 17 days later in the cheese stored at 5 °C compared to 20 °C. When stored at 5 °C, the samples retained adequate sensory characteristics for the entire safe storage time. The effects of storage conditions on BAs formation are relevant to reducing the risk associated with consumption of cheese high in BAs.

scholarly journals Impact of Different Storage Conditions on Composition of Lemongrass (Cymbopogon citratus L.) Essential Oil of Tien Giang Province, Vietnam

2020 ◽  
Vol 32 (11) ◽  
pp. 2743-2747
Author(s):  
Thi Kim Ngan Tran ◽  
Tan Phat Dao ◽  
Thi Cam Quyen Ngo ◽  
Thien Hien Tran ◽  
Ung Thanh Dat ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Essential Oil ◽  
Essential Oils ◽  
Storage Time ◽  
Physical Stability ◽  
Chemical Properties ◽  
Storage Conditions ◽  
Citronella Oil ◽  
Main Components ◽  
Physical And Chemical

Essential oils are known to be susceptible to changes and degradation that can lead to loss of quality and pharmacological properties. In this work, lemongrass essential oil is stored under different storage conditions under the influence of light and temperature, assessing the physical and chemical properties as well as the chemical composition of the citronella essential oil respectively. The change in the chemical composition of citronella oil is determined based on the storage time of 4 months under different conditions i.e. light (45 ºC) and in dark (4 ºC). To determine the change in the composition of the essential oil, based on the results of GC-MS analysis methods to monitor the chemical changes of the essential oil. The content of main components of citral and β-myrcene increases significantly after storage time under the influence of light and temperature. Some low content components (β-citronello, β-caryophyllen, p-cymen-8-ol, etc.) are likely to be oxidized and lost under light conditions, even in the dark. Therefore, the importance of external storage factors for the chemical and physical stability of essential oils is a matter of concern to control the quality of scientific evaluation.

Development and Validation of an HPLC Method for Determination of Spirotetramat and Spirotetramat cis enol in Various Vegetables and Soil

2013 ◽  
Vol 96 (3) ◽  
pp. 670-675 ◽  
Author(s):  
Balwinder Singh ◽  
Kousik Mandal ◽  
Sanjay K Sahoo ◽  
Urvashi Bhardwaj ◽  
Raminderjit Singh Battu
Keyword(s):  
Analytical Method ◽  
Anhydrous Sodium Sulfate ◽  
Hplc Method ◽  
Array Detector ◽  
Photodiode Array Detector ◽  
Photodiode Array ◽  
Precision And Accuracy ◽  
Hplc Grade Acetonitrile ◽  
Development And Validation

Abstract An easy and simple analytical method was standardized and validated for the estimation of residues of spirotetramat and its metabolite spirotetramat cis enol in various substrates: okra fruits, brinjal leaves and fruits, green chili, red chili, and soil. The samples were extracted with acetonitrile, diluted with brine solution, partitioned into dichloromethane, dried over anhydrous sodium sulfate, and cleaned up by treatment with activated charcoal powder. Final clear extracts were concentrated under vacuum and reconstituted with HPLC grade acetonitrile. Residues were estimated using HPLC with a photodiode array detector and a C18 column, and confirmed by HPTLC. Acetonitrile was used as the mobile phase at 0.4 mL/min. Both spirotetramat and spirotetramat cis enol presented distinct peak at retention times of 8.518 and 7.598 min, respectively. Consistent recoveries ranging from 82 to 97% for spirotetramat and spirotetramat cis enol were observed when samples were spiked at 1.00 to 0.03 mg/kg levels. The LOQ of the method was found to be 0.03 mg/kg. The analytical method was validated in terms of parameters, including selectivity, linearity, precision, and accuracy.

Development and validation of a fast and simple HPLC method for the simultaneous determination of aniline and its degradation products in wastewater

2016 ◽  
Vol 8 (30) ◽  
pp. 5949-5956 ◽  
Author(s):  
Soumia Boulahlib ◽  
Ali Boudina ◽  
Kahina Si-Ahmed ◽  
Yassine Bessekhouad ◽  
Mohamed Trari
Keyword(s):  
High Performance ◽  
Degradation Products ◽  
Reversed Phase ◽  
Hplc Method ◽  
Array Detector ◽  
Simple Method ◽  
Photodiode Array Detector ◽  
Photodiode Array ◽  
Development And Validation

In this study, a rapid and simple method based on reversed-phase high performance liquid chromatography (RP-HPLC) using a photodiode array detector (PDA) for the simultaneous analysis of five pollutants including aniline and its degradation products, para-aminophenol, meta-aminophenol, ortho-aminophenol and phenol, was developed.

STABILITY INDICATING ASSAY METHOD OF SIROLIMUS USING HPLC AND SEPARATION OF ACID DEGRADANT BY HPTLC

INDIAN DRUGS ◽  
2018 ◽  
Vol 55 (04) ◽  
pp. 48-55
Author(s):  
S. Jadhav ◽  
◽  
P. Pisal ◽  
M. Mahajan
Keyword(s):  
Hplc Method ◽  
Assay Method ◽  
Array Detector ◽  
Oxidation Stress ◽  
Stability Indicating ◽  
Rp Hplc ◽  
Photodiode Array Detector ◽  
Photodiode Array ◽  
The Given ◽  
Stressed Sample

A stability indicating RP-HPLC method has been developed and subsequently validated for Sirolimus. The proposed RP-HPLC method utilizes Phenomenex, C18, 3 μm, 4 mm x 150 mm column, mobile phase consisting of acetonitrile and water (65:35 V/V) and UV detection at 277 nm using a photodiode array detector in the stressed sample chromatograms. Crushed sirolimus tablets were exposed to thermal, photolytic, aqueous and oxidation stress conditions and stressed samples were analysed by the proposed method. Peak homogeneity data of the drug peaks were obtained using photodiode array detector. The stressed sample chromatograms demonstrated the specificity of the method for their estimation in presence of degradants. 99.66% degradation was observed in acid degradation study. on the other hand, no degradation was observed in aqueous condition. The given method was linear over a range of 0.1566 mg/mL to 0.4699 mg/mL. The mean recovery was found to be 99.23%. Acid degradant was separated by HPTLC and spectroscopic analysis was performed for the same.

scholarly journals EFFECT OF THE LOG STORAGE OF Pinus taeda L. ON THE QUALITY OF KRAFT PULP

FLORESTA ◽  
2020 ◽  
Vol 50 (4) ◽  
pp. 1844
Author(s):  
Guilherme Giesel ◽  
Martha Andreia Brand ◽  
Flaviana Reis Milagres ◽  
Renato Augusto Pereira Damasio
Keyword(s):  
Pinus Taeda ◽  
Storage Time ◽  
Chemical Properties ◽  
Storage Period ◽  
Wood Properties ◽  
Pinus Taeda L ◽  
Solids Content ◽  
Physical And Chemical ◽  
Soluble Lignin

In pulp production, wood in logs is stored for periods that can range from a few weeks to several months. During storage, changes in the wood properties that affect the pulping process and the quality of the pulp may occur. The objective of this study was to determine the ideal timing of wood storage in logs by evaluating the variations (a) in the chemical properties of wood (b) in the parameters of the pulping process and (c) the quality of the Pinus taeda pulp. Logs were stored in an industrial courtyard for 30, 60, 90, 120 and 150 days. In each storage period, the physical and chemical properties of the wood, the cooking parameters, and the properties of the pulp were analyzed. The chemical properties of wood varied throughout storage, but only the solubility in sodium hydroxide showed a positive and significant correlation with storage time. In pulping, the yield and tailings had an inversely proportional correlation with the storage time, while the organic and total solids content had a positive correlation. As for cellulose quality, arabinan and soluble lignin contents did not vary during storage. The mannan content had a positive and significant correlation with the storage time. Taking into account all the variables analyzed, the storage time of P. taeda logs should be up to 30 days.

scholarly journals SIMULTANEOUS QUANTIFICATION OF PENTAZOCINE AND NALOXONE BY STABILITY INDICATING REVERSE-PHASE-HIGH-PERFORMANCE LIQUID CHROMATOGRAPHIC METHOD

2019 ◽  
pp. 257-262
Author(s):  
RAMA KUMAR KANDULA ◽  
RAJA SUNDARARAJAN
Keyword(s):  
High Performance ◽  
High Performance Liquid Chromatographic ◽  
Hplc Method ◽  
Array Detector ◽  
Forced Degradation ◽  
Stability Indicating ◽  
Photodiode Array Detector ◽  
Photodiode Array ◽  
Alkali Hydrolysis ◽  
Liquid Chromatographic

Objective: The objective of the study was to develope a stability indicating high-performance liquid chromatographic (HPLC) method for simultaneous assay of pentazocine and naloxone in bulk and tablets. Methods: Pentazocine and naloxone were analyzed on Dionex C18 column using 0.1M K2HPO4 buffer (pH 4.0) and methanol (60:40, v/v) as the mobile phase. The concentration of pentazocine and naloxone was quantified by photodiode array detector set at 248 nm. The method was validated in compliance with ICH rules. Pentazocine and naloxone tablet formulation was subjected to forced degradation such as acid, neutral and alkali hydrolysis, oxidation, photo, and thermal degradation. Results: The method was linear, with R2=0.9999 in the concentration range 100–300 μg/ml for pentazocine and R2=0.9995 in the concentration range 1–3 μg/ml for naloxone. The level of detection and quantification was 0.097 μg/ml and 0.322 μg/ml for pentazocine and 0.0073 μg/ml and 0.0243 μg/ml for naloxone, respectively. The degraded products are resolved well from pentazocine and naloxone with significantly different retention time values. From validation results, it was proved that the method is selective, precise, robust, and accurate for the estimation of pentazocine and naloxone simultaneously. Conclusion: The developed stability-indicating HPLC method can be applied for quantitative determination of pentazocine and naloxone in tablets.

scholarly journals RP-HPLC Estimation of Bumetanide and its Impurities in Oral Solid Dosage Form

2019 ◽  
Vol 31 (10) ◽  
pp. 2215-2221
Author(s):  
P. Suresh Kumar ◽  
G.V. Krishna Mohan ◽  
A. Naga Babu
Keyword(s):  
Limit Of Detection ◽  
Degradation Products ◽  
Drug Product ◽  
Pharmaceutical Formulations ◽  
Hplc Method ◽  
Fixed Dose ◽  
Array Detector ◽  
Rp Hplc ◽  
Photodiode Array Detector ◽  
Limit Of Quantitation

A novel and simultaneous stability indicating RP-HPLC method has been developed for quantitative analysis of bumetanide in fixed dose pharmaceutical formulations. Bumetanide and its degradation products are well separated by the Discovery C18, 250 × 4.6 mm, 5 μm column as a stationary phase and (50:50 v/v) of 0.1 % o-phthalaldehyde and acetonitrile as a mobile phase. All the compounds are monitored using photodiode array detector at 254 nm with an isocratic method and the flow rate of 1.0 mL/min was maintained. Validation of method was performed as per International Council for Harmonization (ICH) guidelines and the parameters namely; precision, accuracy, specificity, stability, robustness, linearity, limit of quantitation (LOQ) and limit of detection (LOD) were evaluated. The linearity of the proposed method was found to be 0.315-1.875 μg/mL for bumetanide and its impurities. The developed method is more economical and suitable for laboratory use because of solvent consumption is very less. Hence, the developed method can be used for the determination of bumetanide and its impurities in drug product stability studies and pharmaceutical formulations.

scholarly journals Development and validation of a stability indicating RP-HPLC-DAD method for the determination of bromazepam

PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0244951
Author(s):  
Hany W. Darwish ◽  
Nesma A. Ali ◽  
Ibrahim A. Naguib ◽  
Mohamed R. El Ghobashy ◽  
Abdullah M. Al-Hossaini ◽  
...  
Keyword(s):  
Hplc Method ◽  
Array Detector ◽  
Forced Degradation ◽  
Pharmaceutical Dosage Forms ◽  
Stability Indicating ◽  
Rp Hplc ◽  
Photodiode Array Detector ◽  
Alkaline Conditions ◽  
Development And Validation

A reliable, selective and sensitive stability-indicating RP-HPLC assay was established for the quantitation of bromazepam (BMZ) and one of the degradant and stated potential impurities; 2-(2-amino-5-bromobenzoyl) pyridine (ABP). The assay was accomplished on a C18 column (250 mm × 4.6 mm i.d., 5 μm particle size), and utilizing methanol-water (70: 30, v/v) as the mobile phase, at a flow rate of 1.0 ml min-1. HPLC detection of elute was obtained by a photodiode array detector (DAD) which was set at 230 nm. ICH guidelines were adhered for validation of proposed method regarding specificity, sensitivity, precision, linearity, accuracy, system suitability and robustness. Calibration curves of BMZ and ABP were created in the range of 1–16 μg mL-1 with mean recovery percentage of 100.02 ± 1.245 and 99.74 ± 1.124, and detection limit of 0.20 μg mL-1 and 0.24 μg mL-1 respectively. BMZ stability was inspected under various ICH forced degradation conditions and it was found to be easily degraded in acidic and alkaline conditions. The results revealed the suitability of the described methodology for the quantitation of the impurity (ABP) in a BMZ pure sample. The determination of BMZ in pharmaceutical dosage forms was conducted with the described method and showed mean percentage recovery of 99.39 ± 1.401 and 98.72 ± 1.795 (n = 6), respectively. When comparing the described procedure to a reference HPLC method statistically, no significant differences between the two methods in regard to both accuracy and precision were found.

Sign in / Sign up

Export Citation Format

Share Document