scholarly journals New Analytical Method for Quantifying Flavoring Chemicals of Potential Respiratory Health Risk Concerns in e-Cigarette Liquids

2021 ◽  
Vol 9 ◽  
Author(s):  
Michelle K. Page ◽  
Maciej L. Goniewicz
Keyword(s):  
Health Risk ◽  
Analytical Method ◽  
Respiratory Health ◽  
Internal Standard ◽  
Quadratic Model ◽  
Inhalation Toxicity ◽  
Potential Health ◽  
Ethyl Vanillin ◽  
Limit Of Quantitation ◽  
Lower Limits

Numerous flavoring chemicals are added to e-cigarette liquids to create various flavors. Flavorings provide sensory experience to users and increase product appeal; however, concerns have been raised about their potential inhalation toxicity. Estimating potential health risk of inhaling these chemicals has been challenging since little is known about their actual concentrations in e-cigarette products. To date, a limited number of analytical methods exist to measure the concentrations of flavoring chemicals in e-cigarette products. We have developed an analytical method that accurately and precisely measures the concentrations of 20 flavoring chemicals of potential inhalation risk concerns: 2,3,5-trimethylpyrazine, acetoin, benzaldehyde, benzyl alcohol, butanoic acid, dl-limonene, ethyl maltol, ethyl salicylate, ethyl vanillin, eucalyptol, eugenol, furaneol, isovanillin, l-menthol, maltol, methyl salicylate, pulegone, trans-cinnamaldehyde, triacetin, and vanillin. Calibration and QC solutions were prepared in 50:50 propylene glycol (PG):vegetable glycerin (VG) and 5% H2O and flavoring concentrations ranging from 0.02 to 10.00 mg/ml. Samples of commercial e-cigarette liquids, calibration and QC solutions were combined with 30 µL of an internal standard mix (benzene-d6, pyridine-d5, chlorobenzene-d5, naphthalene-d8 and acenaphthene-d10; 1 mg/ml each) and were diluted 100-fold into methanol. Analysis was performed on an Agilent 7890B/7250 GC/Q-TOF using a DB-624UI column (30 m x 0.25 mmID x 1.4 μm film thickness), with a total runtime of 13.5 min. Calibration curves were fit using a weighted quadratic model and correlations of determination (r2) values exceeded 0.990 for all chemicals. Bias and precision tests yielded values less than 20% and lower limits of quantitation (LLOQ) ranged from 0.02 to 0.63 mg/ml. Over 200 commercially available products, purchased or collected from adult e-cigarette users and spanning a range of flavor categories, were evaluated with this method. Concentrations of pulegone, a suspected carcinogen, varied from below limit of quantitation (BLOQ) to 0.32 mg/ml, while acetoin and vanillin, known precursors to more cytotoxic byproducts, ranged from BLOQ to 1.52 mg/ml and from BLOQ to 16.22 mg/ml, respectively. This method features a wide dynamic working range and allows for a rapid routine analysis of flavoring additives in commercial e-cigarette liquids.

scholarly journals DEVELOPMENT AND VALIDATION OF BIOANALYTICAL HPLC METHOD FOR SIMULTANEOUS ESTIMATION OF CILNIDIPINE AND NEBIVOLOL IN HUMAN PLASMA

2017 ◽  
Vol 9 (10) ◽  
pp. 253
Author(s):  
Aruna G. ◽  
Bharathi K ◽  
Kvsrg Prasad
Keyword(s):  
Human Plasma ◽  
Analytical Method ◽  
Internal Standard ◽  
Hplc Method ◽  
Pharmacokinetic Parameters ◽  
Simultaneous Estimation ◽  
Time Data ◽  
Bioanalytical Method Validation ◽  
Limit Of Quantitation ◽  
The Mean

Objective: To develop and validate a modified isocratic reversed-phase high performance liquid chromatographic (RP-HPLC) method for determination of cilnidipine and nebivolol in human plasma to be used for pharmacokinetic studies.Methods: The drug was extracted from plasma samples by direct protein precipitation technique using acetonitrile. Amlodipine was used as internal standard (IS). Samples were analyzed on BDS C18 column (250 x 4.6 mm, 5 µm), applying ortho phosphoric acid (0.1%): Acetonitrile, at a ratio of 45:55 v/v in isocratic mode as a mobile phase at a flow rate of 1 ml/min to attain adequate resolution. Separations were performed at room temperature and monitored at a wavelength of 260 nm after injection of 50μl samples into the HPLC system. The analytical method was validated according to FDA bioanalytical method validation guidance. The method was applied for pharmacokinetic study of cilnidipine and nebivolol tablets-10 mg and 5 mg were administered as a single dose to 6 healthy male rabbits under fasting condition. Twelve blood samples were withdrawn from each rabbit over 24 h periods. From the plasma concentration-time data of each individual, the pharmacokinetic parameters; Cmax, Tmax, AUC0-t and AUC0-∞ were calculated.Results: A peak area was obtained for cilnidipine and nebivolol at 3.943 and 4.719 min retention time respectively. Linearity was established at a concentration range of 0.20-20 μg/ml (r2=0.999, n=8) for cilnidipine and 0.02-2 μg/ml (r2=0.999, n=8) for nebivolol. The lower limit of quantitation (LLOQ) was identifiable and reproducible at 0.2μg/ml for cilnidipine and 0.02 μg/ml for nebivolol. The coefficients of variation (%cv) of the intra-day and inter-day precision of cilnidipine at 600, 1000 and 1600ng/ml levels were found to be 6.90%, 6.19%, 5.22%; and 7.74%, 6.54%, 5.77%, respectively, which are lower than the accepted criteria limits (15-20 %). The mean recovery (%) cilnidipine at 600, 1000, and 1600ng/ml was found to be 101.03%, 99.27% and 104.87%, and for nebivolol 60, 100, and 160 ng/ml was found to be 106.13%, 107.03% and 98.06% respectively. Stability at different conditions and in autosampler was also established. The mean pharmacokinetic parameters; Cmax, Tmax, AUC0-t and AUC0-∞ were 6 ng/ml, 2 hr, 96.76 mg. hr/ml, 63.45 mg. hr/ml for cilnidipine and 5.8ng/ml, 2hr, 74.78 mg. hr/ml, 100.25 mg. hr/ml for nebivolol respectively.Conclusion: The present analytical method was found to be specific, sensitive, accurate and precise for quantification of cilnidipine and nebivolol in human plasma. It can be successively applied for pharmacokinetics, bioavailability and bioequivalence studies.

scholarly journals METHOD DEVELOPMENT AND VALIDATION FOR ANALYSIS OF DEOXYARBUTININ ANHYDROUS EMULSION SYSTEM USING HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY

2019 ◽  
pp. 172-175 ◽  
Author(s):  
MUCHTARIDI MUCHTARIDI ◽  
IDA MUSFIROH ◽  
AHMAD FAUZI
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Analytical Method ◽  
High Performance ◽  
Method Development ◽  
Limit Of Detection ◽  
Internal Standard ◽  
Emulsion System ◽  
Relative Standard ◽  
Limit Of Quantitation

Objective: The aim of this study is to develop a simple, precise and accurate analytical method of deoxyarbutin in anhydrous emulsion system preparation. Methods: The analysis was conducted using high-performance liquid chromatography (HPLC). Chromatographic analysis was carried out using a reversed phase-C18 column. The mobile consists of two phases methanol and water (60: 40 v/v) at a flow rate of 1.0 ml/min. The determinations were performed using UV detector set at 225 nm. All validation procedures were added with hydroquinone as an internal standard. Results: The method showed coefficient correlation is 0.9978, relative standard deviation (RSD) smaller than 2%, Limit of Detection (LOD) and Limit of Quantitation (LOQ) are 0.599 µg/ml and 1.817 µg/ml respectively. The total amount deoxyarbutin in anhydrous emulsion preparation is 1.964+0.02 % with 98% recovery percentage. Conclusion: The developed HPLC analytical method meets the validation criteria made by International Conference on Harmonisation (ICH).

scholarly journals Development and validation of a simple and rapid UPLC method for the in-vitro estimation of (-)-epigallocatechin-3-gallate in lipid-based formulations

2018 ◽  
Vol 9 (1) ◽  
pp. 7-12 ◽  
Author(s):  
Maha Osama El-Kayal ◽  
Maha Nasr Sayed ◽  
Nahed Dawood Mortada ◽  
Seham Elkheshen
Keyword(s):  
Analytical Method ◽  
Limit Of Detection ◽  
Internal Standard ◽  
Array Detector ◽  
Limit Of Quantification ◽  
Potential Health ◽  
Validation Parameters ◽  
Significant Difference ◽  
Lipid Based Formulation

(-)-Epigallocatechin gallate (EGCG) is a catechin found in green tea that has potential health benefits, such as anti-oxidant, anti-carcinogenic and anti-inflammatory effects. A rapid and sensitive Ultra-Performance Liquid Chromatographic (UPLC) method was developed and validated for the estimation of (-)-epigallocatechin-3-gallate in lipid-based formulation. The UPLC method was conducted on C18 analytical column (50 mm × 2.1 mm, 1.8 μm particle size). The mobile phase consisted of a mixture of acetic acid (1%, v:v; pH = 3), acetonitrile and water at volume ratio of 13:15:72 delivered at a flow rate of 0.5 mL/min. The diode array detector (DAD) acquisition wavelength was set at wavelengths 210 and 280 nm. Caffeine was used as internal standard. The tested validation parameters, i.e., selectivity, linearity, accuracy, precision, and sensitivity (Limit of detection and limit of quantification) were determined at both wavelengths. Results revealed that caffeine and EGCG peaks were eluted at retention times of 0.55 and 0.85 minutes, respectively. The calibration curve was linear over the concentration range of 10-60 μg/mL, with coefficients of determination (r2) of 0.9993 and 0.9998 nm at 210 and 280 nm, respectively. All the validation parameters were found within the acceptable range. The proposed method was successfully applied for the quantitation of EGCG in lipid-based formulation and statistical analysis with a reported method showed no significant difference at p < 0.05. Therefore, the proposed analytical method for EGCG can be considered as a rapid, selective and accurate analytical method that can be used for the quantitative analysis of EGCG.

scholarly journals Development, Validation, and Application of the LC-MS/MS Method for Determination of 4-Acetamidobenzoic Acid in Pharmacokinetic Pilot Studies in Pigs

Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4437
Author(s):  
Paulina Markowska ◽  
Zbigniew Procajło ◽  
Joanna Wolska ◽  
Jerzy Jan Jaroszewski ◽  
Hubert Ziółkowski
Keyword(s):  
Sample Preparation ◽  
Analytical Method ◽  
Half Life ◽  
High Performance ◽  
Internal Standard ◽  
Inosine Pranobex ◽  
Pilot Studies ◽  
Pharmacokinetics Study ◽  
Limit Of Quantitation ◽  
One Step

Each drug has pharmacokinetics that must be defined for the substance to be used in humans and animals. Currently, one of the basic analytical tools for pharmacokinetics studies is high-performance liquid chromatography coupled with mass spectrometry. For this analytical method to be fully reliable, it must be properly validated. Therefore, the aims of this study were to develop and validate a novel analytical method for 4-acetamidobenzoic acid, a component of the antiviral and immunostimulatory drug Inosine Pranobex, and to apply the method in the first pharmacokinetics study of 4-acetamidobenzoic acid in pigs after oral administration. Inosine Pranobex was administered under farm conditions to pigs via drinking water 2 h after morning feeding at doses of 20, 40, and 80 mg/kg. For sample preparation, we used liquid–liquid extraction with only one step—protein precipitation with 1 mL of acetonitrile. As an internal standard, we used deuterium labeled 4-acetamidobenzoic acid. The results indicate that the described method is replicable, linear (r2 ≥ 0.99), precise (2.11% to 13.81%), accurate (89% to 98.57%), selective, and sensitive (limit of quantitation = 10 ng/mL). As sample preparation requires only one step, the method is simple, effective, cheap, and rapid. The results of the pilot pharmacokinetics study indicate that the compound is quickly eliminated (elimination half-life from 0.85 to 1.42 h) and rapidly absorbed (absorption half-life from 0.36 to 2.57 h), and that its absorption increases exponentially as the dose is increased.

Occurrences of Giardia cysts in beach water

1998 ◽  
Vol 38 (12) ◽  
pp. 73-76 ◽  
Author(s):  
B. S. W. Ho ◽  
T.-Y Tam
Keyword(s):  
Health Risk ◽  
Water Sample ◽  
Water Samples ◽  
High Concentration ◽  
Potential Health ◽  
Infectious Dose ◽  
Potential Health Risk ◽  
E Coli ◽  
Beach Water ◽  
Giardia Cysts

A total of 64 beach water samples with various bacteriological quality (Grades 1 to 4) were analysed for their bacteriological and parasitological contents (E coli and Giardia cysts respectively). Results indicated that Giardia cysts were detected in less than 10% of the Grade 1 beach water samples with E coli concentrations of &lt;24/100mL. For Grades 2, 3 & 4 beach water samples, Giardia cysts were found, respectively, in 85, 50 and 64% of the samples. Except for one beach water sample which had an unusually high concentration of Giardia cysts (23 cysts/L), they were generally present at moderate concentrations (&lt;10 cysts/L) in all other beach water samples. Despite moderate levels of Giardia cysts present in beach water of different grades, the potential health risk faced by swimmers bathing in local beach water needs to be carefully assessed as Giardia is known to have a low infectious dose.

scholarly journals Silicon dioxide nanoparticles induced neurobehavioral impairments by disrupting microbiota–gut–brain axis

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Jun Diao ◽  
Yinyin Xia ◽  
Xuejun Jiang ◽  
Jingfu Qiu ◽  
Shuqun Cheng ◽  
...  
Keyword(s):  
Gut Microbiota ◽  
Health Risk ◽  
Silicon Dioxide ◽  
Spatial Learning And Memory ◽  
Rrna Gene ◽  
Silicon Dioxide Nanoparticles ◽  
Potential Health ◽  
Specific Chemical ◽  
Memory Impairments ◽  
Tissue Integrity

Abstract Background Silicon dioxide nanoparticles (SiO2NPs) are widely used as additive in the food industry with controversial health risk. Gut microbiota is a new and hot topic in the field of nanotoxicity. It also contributes a novel and insightful view to understand the potential health risk of food-grade SiO2NPs in children, who are susceptible to the toxic effects of nanoparticles. Methods In current study, the young mice were orally administrated with vehicle or SiO2NPs solution for 28 days. The effects of SiO2NPs on the gut microbiota were detected by 16S ribosomal RNA (rRNA) gene sequencing, and the neurobehavioral functions were evaluated by open field test and Morris water maze. The level of inflammation, tissue integrity of gut and the classical indicators involved in gut–brain, gut–liver and gut–lung axis were all assessed. Results Our results demonstrated that SiO2NPs significantly caused the spatial learning and memory impairments and locomotor inhibition. Although SiO2NPs did not trigger evident intestinal or neuronal inflammation, they remarkably damaged the tissue integrity. The microbial diversity within the gut was unexpectedly enhanced in SiO2NPs-treated mice, mainly manifested by the increased abundances of Firmicutes and Patescibacteria. Intriguingly, we demonstrated for the first time that the neurobehavioral impairments and brain damages induced by SiO2NPs might be distinctively associated with the disruption of gut–brain axis by specific chemical substances originated from gut, such as Vipr1 and Sstr2. Unapparent changes in liver or lung tissues further suggested the absence of gut–liver axis or gut–lung axis regulation upon oral SiO2NPs exposure. Conclusion This study provides a novel idea that the SiO2NPs induced neurotoxic effects may occur through distinctive gut–brain axis, showing no significant impact on either gut–lung axis or gut–liver axis. These findings raise the exciting prospect that maintenance and coordination of gastrointestinal functions may be critical for protection against the neurotoxicity of infant foodborne SiO2NPs.

scholarly journals Metal Contents in Fish from the Bay of Bengal and Potential Consumer Exposure—The EAF-Nansen Programme

Foods ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1147
Author(s):  
Amalie Moxness Reksten ◽  
Zillur Rahman ◽  
Marian Kjellevold ◽  
Esther Garrido Gamarro ◽  
Shakuntala H. Thilsted ◽  
...  
Keyword(s):  
Health Risk ◽  
Bay Of Bengal ◽  
Health Assessment ◽  
Sri Lankan ◽  
Marine Fish Species ◽  
Daily Consumption ◽  
Potential Health ◽  
Potential Consumer ◽  
Metal Contents ◽  
Adults And Children

Fish represent an important part of the Sri Lankan and Bangladeshi diet. However, fish is also a source of contaminants that may constitute a health risk to consumers. The aim of this study was to analyse the contents of arsenic, cadmium, mercury, and lead in 24 commonly consumed marine fish species from the Bay of Bengal and to assess the potential health risk associated with their consumption. Mercury and lead contents did not exceed the maximum limits for any of the sampled species, and consumer exposure from estimated daily consumption was assessed to be minimal for adults and children. Numerous samples exceeded the maximum limit for cadmium (58%), particularly those of small size (≤25 cm). However, consumer exposure was insignificant, and health assessment showed no risk connected to consumption. These data represent an important contribution to future risk/benefit assessments related to the consumption of fish.

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