Determination of levetiracetam by GC-MS and effects of storage conditions and gastric digestive systems on drug samples

Bioanalysis ◽  
2022 ◽  
Author(s):  
Fatih Ahmet Erulaş ◽  
Dotse Selali Chormey ◽  
Ersoy Öz ◽  
Sezgin Bakırdere
Keyword(s):  
Active Compound ◽  
Structural Integrity ◽  
Storage Conditions ◽  
Coefficient Of Determination ◽  
Gas Chromatography Mass Spectrometry ◽  
Calibration Plot ◽  
The Stability ◽  
Storage Temperatures ◽  
Accurate Quantification

Background: Epilepsy is a neurologic condition that is occurs globally and is associated with various degrees of seizures. Levetiracetam is an approved drug that is commonly used to treat seizures in juvenile epileptic patients. Accurate quantification of the drug’s active compound and determining its stability in the stomach after oral administration are important tasks that must be performed. Results & methodology: Levetiracetam was extracted from drug samples and quantified by gas chromatography mass spectrometry using calibration standards. Stability of levetiracetam was studied under various storage conditions and in simulated gastric conditions. The calibration plot determined for levetiracetam showed good linearity with a coefficient of determination value of 0.9991. The limits of detection and quantification were found to be 0.004 and 0.014 μg·ml-1, respectively. The structural integrity of levetiracetam did not change within a 4-h period under the simulated gastric conditions, and no significant degradation was observed for the different storage temperatures tested. Discussion & conclusion: An accurate and sensitive quantitative method was developed for the determination of levetiracetam in drug samples. The stability of the drug active compound was monitored under various storage and gastric conditions. The levetiracetam content determined in the drug samples were within ±10% of the value stated on the drug labels.

scholarly journals Development and validation of the method for the detection of glimepiride via derivatization employing N-methyl-N-(trimethylsilyl) trifluoroacetamide using gas chromatography-mass spectrometry

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Priyanka Verma ◽  
Atul Bajaj ◽  
R. M. Tripathi ◽  
Sudhir K. Shukla ◽  
Suman Nagpal
Keyword(s):  
Diabetes Mellitus ◽  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Drug Users ◽  
Coefficient Of Determination ◽  
Gas Chromatography Mass Spectrometry ◽  
Biological Matrices ◽  
Chromatography Mass Spectrometry ◽  
Ms Analysis ◽  
The Stability

Abstract Background Recent advances in the diversified anti-diabetic drugs have appeared in the startling increase in the count of poisoning cases. The epidemics of diabetes mellitus are increasing; hence, the no. of anti-diabetic drug users raised by 42.9%. The use of glimepiride raised to 24%. As the toxicity and drug cases are also escalating with increasing epidemics of diabetes mellitus, a novel gas chromatography-mass spectrometry (GC-MS) method for detecting glimepiride in biological matrices is developed. Results Liquid-liquid extraction method was employed by using 1-butanol: hexane (50:50, v/v) under an alkaline medium, and then back extraction was done via acetic acid. Distinct derivatization techniques were employed for the sample preparation for GC-MS analysis, i.e., silylation and acylation. Derivatization approaches were optimized under different parameters, i.e., reaction temperature and reaction time. N-Methyl-N-(trimethylsilyl) trifluoroacetamide [MSTFA] was found to be the best sound derivatization reagent for the GC-MS analysis of glimepiride. Total ion current (TIC) mode was selected for the monitoring of ions of trimethylsilyl (TMS) derivative of glimepiride with an m/z ratio of 256. Distinct parameters like specificity, carryover, stability, precision, and accuracy were evaluated for validating the identification method. The GC-MS method is found to be linear and illustrated within the range 500 to 2500 ng/ml with the value of R2 (coefficient of determination) at 0.9924. The stability of the extracted and derivatized glimepiride was accessed with regard to processed/extracted sample conditions and autosampler conditions, respectively. Accuracy at each concentration level was within the + 15% of the nominal concentration. Precision (%) for the interday and intraday analysis was found to be in the respectable spectrum. Conclusion Henceforth, the proposed GC-MS method can be employed for the determination of glimepiride in biological matrices.

Residual 1,2-dibromoethane in mango, capsicum, passionfruit and papaw after fumigation against Queensland fruit fly, Dacus tryoni (Froggatt)

1985 ◽  
Vol 25 (1) ◽  
pp. 214
Author(s):  
KJ Melksham ◽  
HE Munro
Keyword(s):  
Fruit Fly ◽  
Storage Conditions ◽  
Residue Level ◽  
Gas Chromatography Mass Spectrometry ◽  
X Ray ◽  
Maximum Residue Level ◽  
Low Levels ◽  
Rate Of Dissipation ◽  
Time Required

Residual 1,2-dibromoethane (EDB) was measured in mango, capsicum, passionfruit and papaw following treatment with biologically effective levels of EDB. Post-fumigation forcedairing periods, storage conditions and times of storage were varied. The duration of the forced-airing period after fumigation had no significant effect on the rate of dissipation of EDB from mango. Fumigated mango required storage at 21� for at least 3 days before EDB levels fell to the maximum residue level (MRL) of 0.1 mg/kg. Cool storage of mango extended the time required for the EDB level to fall to the MRL to at least 6 days. Fumigated capsicum stored at 21�C required 2 days for EDB levels to fall to the MRL while, with fumigated papaw, this took at least 4 days. Even after storage for 7 days, EDB levels in fumigated passionfruit exceeded the MRL so the fumigation procedure was unsuitable for use with passionfruit. A kinetic model was proposed which explained the behaviour of EDB in the various trials and in other literature reports. All samples were analysed by X-ray fluorescence spectrometry (X-RF) and many results were confirmed more specifically and more sensitively by gas chromatography-mass spectrometry. Comparison ofresults by these two methods, including the results of samples spiked with low levels of EDB, helped remove doubts about the suitability of X-RF for the determination of residual EDB.

scholarly journals An Assessment of Mesoporous Silica Nanoparticle Architectures as Antigen Carriers

Pharmaceutics ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 294 ◽  
Author(s):  
Xinyue Huang ◽  
Helen E Townley
Keyword(s):  
Mesoporous Silica ◽  
Mesoporous Silica Nanoparticles ◽  
High Surface ◽  
Silica Nanoparticle ◽  
Storage Conditions ◽  
Surface Areas ◽  
Antigen Complex ◽  
The Stability ◽  
And Storage ◽  
Storage Temperatures

Mesoporous silica nanoparticles (MSNPs) have the potential to be used as antigen carriers due to their high surface areas and highly ordered pore network. We investigated the adsorption and desorption of diphtheria toxoid as a proof-of-concept. Two series of nanoparticles were prepared—(i) small pores (SP) (<10 nm) and (ii) large pores (LP) (>10 nm). SBA-15 was included as a comparison since this is commercially available and has been used in a large number of studies. External diameters of the particles ranged from 138 to 1509 nm, surface area from 632 to 1110 m2/g and pore size from 2.59 to 16.48 nm. Antigen loading was assessed at a number of different ratios of silica-to-antigen and at 4 °C, 20 °C and 37 °C. Our data showed that protein adsorption by the SP series was in general consistently lower than that shown by the large pore series. Unloading was then examined at 4 °C, 20 °C and 37 °C and a pH 1.2, 4.5, 6.8 and 7.4. There was a trend amongst the LP particles towards the smallest pores showing the lowest release of antigen. The stability of the MSNP: antigen complex was tested at two different storage temperatures, and storage in solution or after lyophilization. After 6 months there was negligible release from any of the particles under any of the storage conditions. The particles were also shown not to cause hemolysis.

Effect of storage of plasma and serum on enzymatic determination of non-esterified fatty acids

2001 ◽  
Vol 38 (3) ◽  
pp. 252-255 ◽  
Author(s):  
Luis García Menéndez ◽  
Ana L Fernández ◽  
Alfredo Enguix ◽  
Constanza Ciriza ◽  
Juan Amador
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Storage Conditions ◽  
The Other ◽  
Specific Reference ◽  
Enzymatic Method ◽  
Esterified Fatty Acids ◽  
Enzymatic Determination ◽  
The Stability

Many contradictory results have been published on the stability of total non-esterified fatty acids in blood, plasma and serum under different storage conditions. The present study was undertaken to investigate the stability of non-esterified fatty acids, measured with an enzymatic method, in samples of EDTA-treated plasma and serum under different temperature conditions. We conclude that EDTA-treated plasma and serum can both be used for analysis. Specific reference values should be established depending on the type of sample chosen. Samples that cannot be analysed immediately can be stored at -20°C for at least 14 days without significant changes in the concentration of total non-esterified fatty acids. None of the other storage conditions and periods studied are suitable for the measurement of non-esterified fatty acid concentration.

scholarly journals Chemical Variability in the Composition of Zhumeria majdae (Rech. F. & Wendelbo) Essential Oil According to Storage Time and Temperature

Horticulturae ◽  
2021 ◽  
Vol 7 (11) ◽  
pp. 463
Author(s):  
Akbar Karami ◽  
Fatemeh Tashani ◽  
Aminallah Tahmasebi ◽  
Filippo Maggi
Keyword(s):  
Essential Oil ◽  
Room Temperature ◽  
Storage Time ◽  
Storage Conditions ◽  
Gas Chromatography Mass Spectrometry ◽  
Average Value ◽  
Oil Storage ◽  
Chemical Variability ◽  
Refrigerator Temperature ◽  
Storage Temperatures

Zhumeria majdae (Rech. F. & Wendelbo) is an aromatic herb belonging to the Lamiaceae family, traditionally employed in the Persian medicine for the treatment of a wide number of diseases. In the present study, the chemical composition of Z. majdae essential oil obtained from the plant’s aerial features, and stored at various temperatures (refrigerator temperature 4 °C, freezer temperature −20 °C, and room temperature 20 ± 3 °C) and times (0, 3, 6, and 9 months) was studied. The essential oil was isolated through hydrodistillation, and its composition was evaluated by gas chromatography/mass spectrometry (GC/MS). The results showed that the composition of essential oils changed as a function of the various storage temperatures and times. Linalool (34.85–48.45%), camphor (27.09–39.17%), limonene (1.97–4.88%), and camphene (1.6–4.84%) made up the main volatile compounds which showed differences in their concentrations according to the various storage conditions. Notably, when compared to a non-stored treatment sample (analyzed immediately after essential oil collection), the amount of linalool and camphor increased in all samples stored in all conditions of temperature and time, with the exception of the samples stored for nine months at room temperature. On the other hand, limonene and camphene contents decreased during the storage treatments, showing that the highest content of these compounds occurred in the non-stored treatment. Essential oil storage at the freezer temperature and for three months storage time resulted in the highest average value of the major constituents, highlighting these as the best conditions for obtaining the highest content of the major compounds.

scholarly journals Evaluation of Synthetic Cannabinoid Metabolites in Human Blood in the Absence of Parent Compounds: A Stability Assessment

2020 ◽  
Author(s):  
Alex J Krotulski ◽  
Sandra C Bishop-Freeman ◽  
Amanda L A Mohr ◽  
Barry K Logan
Keyword(s):  
Accurate Determination ◽  
Synthetic Cannabinoids ◽  
The United States ◽  
Storage Conditions ◽  
Synthetic Cannabinoid ◽  
Blood Samples ◽  
Flight Mass Spectrometry ◽  
Acid Metabolites ◽  
The Stability

Abstract Synthetic cannabinoids represent a chemically diverse class of novel psychoactive substances (NPS) responsible for large analytical and interpretative challenges for forensic toxicologists. Between 2016 and 2019, the three most prevalent synthetic cannabinoids in the United States were MMB-FUBINACA (FUB-AMB), 5F-MDMB-PINACA (5F-ADB) and 5F-MDMB-PICA, based on results from seized drug and toxicology testing. In 2018, accurate determination of synthetic cannabinoid positivity was brought into question as it was determined that the metabolites of these drug species were present in the absence of parent compounds in forensically relevant blood samples. During this study, the stability of MMB-FUBINACA, 5F-MDMB-PINACA and 5F-MDMB-PICA was evaluated, as well as the characterization of breakdown products. A liquid–liquid extraction method was assessed for recovery of basic parent compounds and acidic metabolites and deemed fit for use in this study. Analysis was performed by liquid chromatography–quadrupole time-of-flight mass spectrometry (LC–QTOF-MS) using a SCIEX TripleTOF® 5600+. All three synthetic cannabinoids were found to be unstable when stored in blood at either room temperature or refrigerated; all analytes were considerably more stable when stored in the freezer. All three synthetic cannabinoids degraded to their respective butanoic acid metabolites: MMB-FUBINACA 3-methylbutanoic acid, 5F-MDMB-PINACA 3,3-dimethylbutanoic acid and 5F-MDMB-PICA 3,3-dimethylbutanoic acid. All three of these metabolites were studied and determined to be stable in blood at all storage conditions. Considering these results, our laboratory continued testing for synthetic cannabinoid metabolites in blood samples and found 83 positives (21%) for only a synthetic cannabinoid metabolite. A case report is presented herein where 5F-MDMB-PINACA 3,3-dimethylbutanoic acid was identified in the absence of 5F-MDMB-PINACA. Forensic toxicologists should be aware of the results of this study as they directly impact analytical consideration for test development and implementation, as well as interpretation of findings.

scholarly journals Evolution of Extra Virgin Olive Oil Quality under Different Storage Conditions

Foods ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1945
Author(s):  
Soraya Mousavi ◽  
Roberto Mariotti ◽  
Vitale Stanzione ◽  
Saverio Pandolfi ◽  
Valerio Mastio ◽  
...  
Keyword(s):  
Olive Oil ◽  
Low Temperatures ◽  
Oil Quality ◽  
Virgin Olive Oil ◽  
Extra Virgin Olive Oil ◽  
Storage Conditions ◽  
Legal Limits ◽  
The Stability ◽  
Storage Temperatures

The extent and conditions of storage may affect the stability and quality of extra virgin olive oil (EVOO). This study aimed at evaluating the effects of different storage conditions (ambient, 4 °C and −18 °C temperatures, and argon headspace) on three EVOOs (low, medium, and high phenols) over 18 and 36 months, analyzing the main metabolites at six time points. The results showed that low temperatures are able to maintain all three EVOOs within the legal limits established by the current EU regulations for most compounds up to 36 months. Oleocanthal, squalene, and total phenols were affected by storage temperatures more than other compounds and degradation of squalene and α-tocopherol was inhibited only by low temperatures. The best temperature for 3-year conservation was 4 °C, but −18 °C represented the optimum temperature to preserve the organoleptic properties. The present study provided new insights that should guide EVOO manufacturers and traders to apply the most efficient storage methods to maintain the characteristics of the freshly extracted oils for a long conservation time.

scholarly journals EFFECT OF BROKEN DOLOSSE ON BREAKWATER' STABILITY

1976 ◽  
Vol 1 (15) ◽  
pp. 145 ◽  
Author(s):  
D. Donald Davidson ◽  
Dennis G. Markle
Keyword(s):  
Structural Integrity ◽  
Accurate Determination ◽  
Wave Forces ◽  
Design Data ◽  
Hydraulic Design ◽  
Overall Stability ◽  
Physical Limitations ◽  
The Stability ◽  
Water Bottom

Although the use of rubble-mound structures for protection of coastal areas is common throughout the world and considerable hydraulic design data have been developed to aid the designer, very little data are provided on the structural integrity of individual armor units and the effect of broken units on the stability of such structures. The forces to which such structures are subjected are complicated and vary with type and geometry of the structure, depth of water, bottom configuration seaward of the structure, water level relative to the crown of the structure, and wave dimensions. Since all of these parameters are involved, accurate determination of wave forces cannot be calculated; and although it is not impossible to model the structural strength of armor units or measure forces on individual armor units, there are physical limitations which make the tasks extremely difficult. There is one way, however, that a breakwater stability model, as it exists today, can provide useful information on this subject and that is to purposely break given numbers of armor units and observe the effect on the overall stability of the structure. Such tests have been conducted at the U. S. Army Engineer Waterways Experiment Station for the Atlantic Generating Station (AGS) Breakwater in which specific answers were desired; thus, the data are limited to the dolos armor unit. The data do provide, however, significant indications regarding the type and extent of breakage (cluster or random) that is most detrimental to the overall stability of the structure; whether costly reinforcing steel is warranted to assure reduced armor breakage; and where necessary, data from this type study can be used as a basis for setting maintenance criteria that will prevent deterioration of the breakwater due to armor unit breakage.

Stability of Chlorophenols and Their Acetylated Derivatives in Water: Sample Storage Procedures

2014 ◽  
Vol 97 (1) ◽  
pp. 179-182
Author(s):  
Paulo de Morais ◽  
Teodor Stoichev ◽  
M Clara P Basto ◽  
Pedro N Carvalho ◽  
M Teresa S D Vasconcelos
Keyword(s):  
Sodium Chloride ◽  
Acetic Anhydride ◽  
Water Samples ◽  
Storage Conditions ◽  
Storage Space ◽  
Sample Storage ◽  
Different Temperatures ◽  
Low Levels ◽  
The Stability

Abstract The determination of chlorophenols (CPs) in water samples is a subject of increasing interest. Reduction of sample storage space and the stability of CPs when present at very low levels are still problems that deserve research. The stability of CPs at ng/L levels at different temperatures and in the presence or absence of sodium carbonateand acetic anhydride was studied for up to 39 days. Stable and reproducible CP concentrations for about a month of storage in both river and wastewater were achieved in two storage conditions as follows: at –18°C with addition of 10% sodium chloride; and at 4°C with addition of both 10% sodium chloride and 10 mg/mL sodium carbonate. These sample treatments are good alternatives to the immobilization of CPs on SPE cartridges in terms of both analyte stability and saving of storage space.

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