scholarly journals Effects of UV-Light, Temperature and Storage on the Stability and Biological Effectiveness of Some Insecticides

2012 ◽  
Vol 52 (2) ◽  
pp. 275-280 ◽  
Author(s):  
Mahmoud Soliman
Keyword(s):  
Uv Light ◽  
Immature Stages ◽  
Light Storage ◽  
Degradation Rates ◽  
Residual Level ◽  
Different Temperatures ◽  
Biological Effectiveness ◽  
The Stability ◽  
And Storage ◽  
Uv Rays

Effects of UV-Light, Temperature and Storage on the Stability and Biological Effectiveness of Some InsecticidesThe degradation and biological effectiveness of five insecticides, ES-Fenvalerate (Soumi Gold), pirimicarb (Afox), imidacloprid (Emax), buprofenzin (Ablloud) and methomyl (Methiolate) in their aqueous preparations and emulsifiable concentrates, on immature stages of whitefly insectBemisia tabaci. when exposed to UV-light, two different temperatures and daylight and dark storage after exposure intervals was studied. The results indicated the degradation rates of the five tested insecticides varied according to the chemical structure, time of exposure and wavelength of UV-rays used. Of all the five insecticides, methomyl was the most affected by UV-rays. Losses of ES-Fenvalerate, pirimicarb, imidacloprid, buprofenzin and methomyl within this period were 11.30, 14.80, 29.03, 31.83 and 39%, respectively after one hour to UV-ray exposure. A significant increase in LC50value was obtained when ES-Fenvalerate in aqueous preparation was exposed to UV-light for 6 hr. The LC50values and their confidence ranges in aqueous preparations and emulsifiable concentrates were 107.5 ppm (51.7-199.2) and 93.10 ppm (48.3-150.4). The residual level of Fenvalerate, pirimicarb, imidacloprid, buprofenzin and methomyl were 13.52, 17.54 ppm; 12.67, 15.87 ppm; 11.78, 16.47 ppm; 11.38, 14.73 ppm; and 11.36, 11.83 ppm for two days exposed to daylight and dark storage. Insecticides could be arranged according to LC50values at zero-time as follow: ES-Fenvalerate, pirimicarb, imidacloprid, buprofenzin and methomyl. The corresponding values of LC50were 3.40, 15.4, 15.6, 16.2 and 23.5 ppm for daylight storage. On the other hand, the dark storage exposure for the tested insecticides could be arranged according to LC50values as follow: ES-Fenvalerate, imidacloprid, pirimicarb, buprofenzin and methomyl. The corresponding LC50were 3.20, 14.8, 14.9, 15.9 and 21.3 ppm, respectively. In general, the amount recovered after a one day, 45°C exposure were 14.63, 12.84, 12.79, 12.14 and 11.76 ppm, for ES-Fenvalerate, pirimicarb, imidacloprid, buprofenzin and methomyl, respectively. While the amounts recovered after a three day 45°C exposure were 9.28, 8.34, 7.76, 7.72 and 5.83 ppm for ES-Fenvalerate, pirimicarb, imidacloprid, buprofenzin and methomyl, respectively. Efficiency against whitefly insect,B. tabaciimmature stages was affected when aqueous preparations of the five tested insecticides were stored at 45°C for one and three days, compared to those stored under normal condition of 25°C for the same periods of time. Generally it could be concluded that buprofenzin n and methomyl, were more affected by UV-light, storage and temperature than ES-Fenvalerate, pirimicarb, imidacloprid.

PHYTOCHEMICAL CHARACTERIZATION AND TANNIN STABILITY TEST FROM KLUWEK (Pangium edule Reinw)

2019 ◽  
Vol 1 (02) ◽  
pp. 44-49
Author(s):  
Siti Warnasih ◽  
Uswatun Hasanah
Keyword(s):  
Secondary Metabolite ◽  
Uv Light ◽  
Heating Temperature ◽  
Natural Dye ◽  
Stability Test ◽  
Tannin Content ◽  
The Stability ◽  
And Storage ◽  
Duration Of Heating ◽  
Uv Rays

One of the herbs that can be used as a source of natural dye is the kluwek which is brown. This study aims to determine the type of secondary metabolite compounds producing color, and to determine the stability of tannin in various conditions such as pH, oxidizing, UV rays, heating temperature, and storage using UV-Vis spectrophotometry method. This research includes preparation of kluwek, extraction with acetone:water (7:3) with maceration method, phytochemical test (tannin, flavonoid, carotenoid, and anthocyanin) and total tannins, and tannin stability test on various pH, oxidizing, UV rays, temperature and duration of heating, and storage using the UV-Vis spectrophotometry method. The results obtained are kluwek extract containing tannin, flavonoid, carotenoid, and anthocyanin compounds, and total tannins 2.80%. Based on the tannin content, kluwek extract stable at pH 6-7, heating 60-80 oC, and storage up to 9 days at temperature 27 C, and kluwek extract unstable when contact with 1% H2O2, UV light, and if kept at cold temperature (10 ?C).

scholarly journals Moisture sorption isotherms of castor beans. Part 1: Mathematical modeling and hysteresis

2016 ◽  
Vol 20 (8) ◽  
pp. 751-756 ◽  
Author(s):  
André L. D. Goneli ◽  
Paulo C. Corrêa ◽  
Gabriel H. H. de Oliveira ◽  
Osvaldo Resende ◽  
Munir Mauad
Keyword(s):  
Moisture Content ◽  
Sorption Isotherms ◽  
Moisture Sorption ◽  
Environmental Condition ◽  
Adsorption And Desorption ◽  
Moisture Sorption Isotherms ◽  
Different Temperatures ◽  
The Difference ◽  
The Stability ◽  
And Storage

ABSTRACT Sorption isotherms are of great importance in post-harvest procedures, especially for predicting drying and storage, which help to establish the final moisture content of the product under certain environmental condition. Hysteresis is a phenomenon that occurs due to the difference between adsorption and desorption curves, which aids the evaluation of chemical and microbiological deteriorations, indicating the stability of stored products. Moisture sorption isotherms of castor beans were determined and hysteresis was analyzed. Static gravimetric technique at different temperatures (25, 35, 45 and 55 ± 1 °C) was used. Saturated salt solutions in the range of 37-87% ± 2% were utilized to create the required controlled relative humidity environment. Equilibrium moisture content data were correlated by different mathematical models and the Modified Halsey model presented good adjustment for the data, according to statistical procedures. Hysteresis between adsorption and desorption isotherms is present over the range of 0.2-0.9 of water activity, regardless of the temperature. This phenomenon decreases with temperature increase.

scholarly journals Preservation of Azotobacter chroococcum vegetative cells in dry polymers

2014 ◽  
Vol 20 (2) ◽  
pp. 201 ◽  
Author(s):  
Daniel Rojas-Tapias ◽  
Oriana Ortega Sierra ◽  
Diego Rivera Botía ◽  
Ruth Bonilla
Keyword(s):  
Storage Conditions ◽  
Azotobacter Chroococcum ◽  
Bacterial Degradation ◽  
Protective Agent ◽  
Degradation Rates ◽  
Different Temperatures ◽  
And Storage ◽  
Temperature Time ◽  
Long Term Preservation

We studied the preservation of Azotobacter chroococcum C26 using three dry polymers: carrageenin, sodium alginate, and HPMC, using a method of accelerated degradation. Bacterial viability, as response variable, was measured at three temperatures in four different times, which was followed by calculation of bacterial degradation rates. Results showed that temperature, time of storage, and protective agent influenced both viability and degradation rates (P;lt;0.05). We observed, using the Arrhenius thermodynamic model, that the use of polymers increased the activation energy of bacterial degradation compared to control. We obtained thermodynamic models for each polymer, based on the Arrhenius equation, which predicted the required time for thermal degradation of the cells at different temperatures. Analysis of the models showed that carrageenin was the best polymer to preserve A. chroococcum C26 since ~ 900 days are required at 4 ºC to reduce its viability in two log units. We conclude, therefore, that long-term preservation of A. chroococcum C26 using dry polymers is suitable under adequate preservation and storage conditions.

scholarly journals Stability and Photoisomerization of Stilbenes Isolated from the Bark of Norway Spruce Roots

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 1036
Author(s):  
Harri Latva-Mäenpää ◽  
Riziwanguli Wufu ◽  
Daniel Mulat ◽  
Tytti Sarjala ◽  
Pekka Saranpää ◽  
...  
Keyword(s):  
Norway Spruce ◽  
Uv Light ◽  
Light Exposure ◽  
Fluorescent Light ◽  
Spectroscopic Techniques ◽  
Functional Ingredients ◽  
The Stability ◽  
Antibacterial And Antifungal ◽  
New Compounds ◽  
And Storage

Stilbenes or stilbenoids, major polyphenolic compounds of the bark of Norway spruce (Picea abies L. Karst), have potential future applications as drugs, preservatives and other functional ingredients due to their antioxidative, antibacterial and antifungal properties. Stilbenes are photosensitive and UV and fluorescent light induce trans to cis isomerisation via intramolecular cyclization. So far, the characterizations of possible new compounds derived from trans-stilbenes under UV light exposure have been mainly tentative based only on UV or MS spectra without utilizing more detailed structural spectroscopy techniques such as NMR. The objective of this work was to study the stability of biologically interesting and readily available stilbenes such as astringin and isorhapontin and their aglucones piceatannol and isorhapontigenin, which have not been studied previously. The effects of fluorescent and UV light and storage on the stability of trans stilbenes were assessed and the identification and characterisation of new compounds formed during our experiments were carried out by chromatographic (HPLC, GC) and spectroscopic techniques (UV, MS, NMR). The stilbenes undergo a trans to cis isomerisation under extended UV irradiation by intramolecular cyclisation (by the formation of a new C-C bond and the loss of two hydrogens) to phenanthrene structures. The characterised compounds are novel and not described previously.

scholarly journals Stability of the trastuzumab biosimilar ABP 980 compared to reference product after intravenous bag preparation, transport and storage at various temperatures, concentrations and stress conditions

2020 ◽  
Vol 9 (1) ◽  
pp. 5-13 ◽  
Author(s):  
Shon Crampton ◽  
Alla Polozova ◽  
Darin Asbury ◽  
Alexis Lueras ◽  
Paul Breslin ◽  
...  
Keyword(s):  
Infusion Pump ◽  
Significant Loss ◽  
High Dose ◽  
Different Temperatures ◽  
Transportation Simulation ◽  
Post Infusion ◽  
Biological Potency ◽  
The Stability ◽  
The Impact ◽  
And Storage

Study objectives: To investigate the quality and in-use stability of diluted ABP 980 (a trastuzumab biosimilar) versus reference trastuzumab to mimic dosing in intravenous (IV) bags, transportation and extended storage prior to infusion. Methods: Low dose (70 mg; 0.3 mg/mL) and high dose (1,200 mg; 3.8 mg/mL) ABP 980 and reference trastuzumab solutions were prepared, light-protected and subjected to transportation simulation and storage (2°C–8°C or 30°C for 5 weeks, followed by 48 hours at 30°C). Stability was assessed pre- and post-transport; at Weeks 1, 2, 4, and 5; at Week 5 after 48 hours at 30°C; and pre- and post-infusion using an infusion pump. Results: Across doses and temperatures, there was little change in high molecular weight species and no detectable loss in purity. Following storage, visible particles (> 125 µm) were intermittently observed for both products, with increased subvisible particles detected with low doses. Extended storage at 2°C–8°C did not lead to any significant loss in the active molecule, with consistent biological potency across doses and temperatures for both products. Higher-dose dilutions maintained pH closer to the initial formulation specifications. Discussion: This study examined the impact of dilution, transport and extended storage at different temperatures on the stability of ABP 980 and reference trastuzumab. No major differences between the two products were observed. Conclusion: Across storage temperatures, multiple stability-indicating assays demonstrated no clinically meaningful impact to product quality and stability for both ABP 980 and reference trastuzumab, which provides assurance that ABP 980 retains stability and activity over extended storage periods.

scholarly journals Stability of lactoferrin and lysozyme in human milk at various temperatures and duration of storage

2021 ◽  
Vol 27 (2) ◽  
Author(s):  
◽  
Sumirah Budi Pertami ◽  
Agus Setyo Utomo ◽  
Siti Nur Arifah ◽  
◽  
...  
Keyword(s):  
Human Milk ◽  
Room Temperature ◽  
Storage Time ◽  
Enzyme Linked Immunosorbent Assay ◽  
Milk Samples ◽  
Duration Of Storage ◽  
Different Temperatures ◽  
Bioactive Content ◽  
The Stability ◽  
And Storage

Introduction: Exclusive breastfeeding, especially in the first six months, is essential for infants as it provides nutrition and protection against various diseases. Colostrum, which is found in the first breast milk produced, contains various protective factors, such as lactoferrin and lysozyme. Human milk can be stored at room temperature, refrigerated, or kept frozen. Several factors affect the stability of the bioactive content in human milk, such as temperature and storage time. The aim of this study was to measure the stability of lactoferrin and lysozyme levels in human milk during the first six hours (h) at different temperatures and compare it with that of frozen human milk. Methods: Human milk samples were obtained from 11 breastfeeding mothers using certain criteria. The human milk was stored at room temperature and 4°C for 1, 3, and 6 h and classified as never frozen, while frozen human milk was stored at -20°C for 1, 3, and 6 days. Measurement of the lactoferrin and lysozyme levels was performed using enzyme-linked immunosorbent assay. Results: The results showed that storage at room temperature significantly reduced lactoferrin and lysozyme levels. Lactoferrin levels in frozen human milk did not significantly decrease during the first six days. Meanwhile, the lysozyme levels in frozen human milk decreased significantly. Conclusion: The levels of lactoferrin and lysozyme in frozen human milk stored for the first six days were more stable than those stored at room temperature and 4°C in the first 6 h.

scholarly journals COMPARISON BETWEEN CUSTOMS PREPARATIONS AND WORKOUT PREPARATIONS FOR PESTICIDE PROFENOFOS FROM DIFFERENT SOURCES AND UNDER SPECIFIC ENVIRONMENTAL CONDITIONS

2021 ◽  
Vol 21 (No 1) ◽  
Author(s):  
Hala. M. Ibrahim
Keyword(s):  
Uv Light ◽  
Degradation Products ◽  
Light Exposure ◽  
Sunlight Exposure ◽  
Factors Affecting ◽  
Trade Name ◽  
Before And After ◽  
The Stability ◽  
And Storage ◽  
Different Sources

Four generic profenfos formulations under trade name Camkron and Tiliton 72% EC (customs, workout) for each of those, which currently applied in Egypt from different companies were studied for the effects of sunlight exposure, UV-light, PH and storage on the stability of profenofos, its respective impurity 4-bromo-2-chlorophenol content and water as a relevant impurity. Exposure to sunlight, UV-light at 16 hours and storage for 14 days at 54±2o C indicated various degradation effects on profenofos content and increase the formation of its impurity 4-bromo-2-chlorophenol and the change in PH in long period cause breakdown of the active substance instability of some component. The storage of profenofos at intervals of 3, 7 and 14 days at 54 ± 2o C from the results obtained showed serious effects on the rate of degradation of profenofos and the increase in the rate of formation of 4-bromo-2-chlorophenol, as well as on sunlight, UV-light exposure, for all of the profenofos formulations under study. It found that the Camkron (workout) is invalid for use it may be due to several factors affecting the consistency of the formulation of profenofos in the manufacturing process, the origins of technical materials, the use of various forms of adjuvants and the long storage time in poor conditions. Analysis before and after storage, sunlight exposure, UV-light using GC-MS identified four degradation products: 4-bromo-2-chlorophenol, O-(4-bromophenyl) O-ethyl S-propyl phosphorothioate, O-(2-chlorophenyl) O-ethyl S-propyl phosphorothioate and O-(4-bromo-2-chlorophenyl) S-propyl hydrogen phosphorothioate and also used IR spectra.

Sorbitol enhances the physicochemical stability of B12 vitamers

2020 ◽  
Vol 90 (5-6) ◽  
pp. 439-447 ◽  
Author(s):  
Andrew Hadinata Lie ◽  
Maria V Chandra-Hioe ◽  
Jayashree Arcot
Keyword(s):  
Ascorbic Acid ◽  
Uv Light ◽  
Heat Exposure ◽  
Water Soluble ◽  
Uv Exposure ◽  
Physicochemical Stability ◽  
Before And After ◽  
The Stability

Abstract. The stability of B12 vitamers is affected by interaction with other water-soluble vitamins, UV light, heat, and pH. This study compared the degradation losses in cyanocobalamin, hydroxocobalamin and methylcobalamin due to the physicochemical exposure before and after the addition of sorbitol. The degradation losses of cyanocobalamin in the presence of increasing concentrations of thiamin and niacin ranged between 6%-13% and added sorbitol significantly prevented the loss of cyanocobalamin (p<0.05). Hydroxocobalamin and methylcobalamin exhibited degradation losses ranging from 24%–26% and 48%–76%, respectively; added sorbitol significantly minimised the loss to 10% and 20%, respectively (p < 0.05). Methylcobalamin was the most susceptible to degradation when co-existing with ascorbic acid, followed by hydroxocobalamin and cyanocobalamin. The presence of ascorbic acid caused the greatest degradation loss in methylcobalamin (70%-76%), which was minimised to 16% with added sorbitol (p < 0.05). Heat exposure (100 °C, 60 minutes) caused a greater loss of cyanocobalamin (38%) than UV exposure (4%). However, degradation losses in hydroxocobalamin and methylcobalamin due to UV and heat exposures were comparable (>30%). At pH 3, methylcobalamin was the most unstable showing 79% degradation loss, which was down to 12% after sorbitol was added (p < 0.05). The losses of cyanocobalamin at pH 3 and pH 9 (~15%) were prevented by adding sorbitol. Addition of sorbitol to hydroxocobalamin at pH 3 and pH 9 reduced the loss by only 6%. The results showed that cyanocobalamin was the most stable, followed by hydroxocobalamin and methylcobalamin. Added sorbitol was sufficient to significantly enhance the stability of cobalamins against degradative agents and conditions.

Preparation, Stabilization and Some Properties of Purified Human Plasmin*

1964 ◽  
Vol 11 (01) ◽  
pp. 075-084 ◽  
Author(s):  
Daniel L Kline ◽  
Jacob B Fishman ◽  
Keyword(s):  
Plasminogen Activator ◽  
Stable Form ◽  
Neutral Ph ◽  
The Stability ◽  
And Storage

Summary1. Lysine increased the solubility, decreased the SK requirement and increased the stability of plasmin prepared from purified plasminogen by SK activation.2. A procedure is presented for the rapid and quantitative conversion of plasminogen to plasmin and storage of the plasmin in stable form at neutral pH as a lyophilized powder.3. Approximately 10% for the plasminogen molecule was split off during its activation. No carbohydrate was lost.4. The plasmin isolated was homogeneous in the ultracentrifuge at pH 2.5 and was quantitatively convertible to plasminogen activator by the addition of SK.

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