Liquid Chromatography Technique Research Articles

HPLC analysis of costunolide from Costus speciosus (Koen ex. Retz.) Sm. plants of Chhattisgarh region

Costus speciosus (Koen ex. Retz.) Sm. is a medicinal plant known for its therapeutic properties, prominently attributed to its bioactive constituents like costunolide, diosgenin, eremanthin etc. This study presents a detailed investigation on the quantitative analysis of costunolide in Costus speciosus plants collected from different geographical regions of Chhattisgarh, employing High-Performance Liquid Chromatography (HPLC) technique. The research methodology involved the crude extraction of metabolites from the rhizome using methanol as solvent followed by HPLC analysis. The results revealed significant variations in the content of costunolide among the collected samples, possibly influenced by environmental factors and genetic variability. Moreover, phytochemical characterization of Costus speciosus extracts was conducted to complement the quantitative analysis. This study contributes to the understanding of the phytochemical profile of Costus speciosus plants in the Chhattisgarh region. The findings help to get the elite plant with significant concentration and hold implications for the standardization and quality control of herbal medicines derived from Costus speciosus, facilitating their utilization in pharmaceutical and therapeutic applications.

Quality by Design Approach for the Development and Validation of a Robust RP-HPLC Method for the Estimation of Aloe-Emodin

Introduction/Objective: The current study examines the methodical Quality by Design (QbD) that facilitated the creation of an easy-to-use, quick, affordable, and stability-indicating reversed- phase high-performance liquid chromatography (RP-HPLC) technique for the efficient analysis of aloe-emodin. Methods: The chromatographic conditions were optimized with the Design Expert software 11.0 version, i.e., flow rate, buffer concentration, and column temperature. Results: The results of the linearity graph show R2 = 0.9988. The LOQ was 0.07949 μg/mL and the LOD was 0.02623 μg/mL. According to ICH rules, the technique validation parameters were within the allowed range. Utilizing the Design Expert 11.0 version, the Box–Behnken design experimental design explains the relationships between flow rate, buffer concentration, and column temperature at three distinct levels. The responses were monitored: the retention time (Rt), tailing factor (Tf), and number of theoretical plates (NTPs). Conclusion: The suggested approach was appropriate for quantitative determination and may be used in clinical pharmacokinetic investigations, biopharmaceutics, accredited testing laboratories, and quality control departments in enterprises.

Evaluating larvicidal, ovicidal and growth inhibiting activity of five medicinal plant extracts on Culex pipiens (Diptera: Culicidae), the West Nile virus vector

Mosquitoes, one of the deadliest animals on the planet, cause millions of fatalities each year by transmitting several human illnesses. Synthetic pesticides were previously used to prevent the spread of diseases by mosquitoes, which was effective in protecting humans but caused serious human health problems, environmental damage, and developed mosquito pesticide resistance. This research focuses on exploring new, more effective, safer, and environmentally friendly compounds to improve mosquito vector management. Phytochemicals are possible biological agents for controlling pests and many are target-specific, rapidly biodegradable, and eco-friendly. The potential of extracts of Lantana camara, Melia azedarach, Nerium oleander, Ricinus communis, and Withania somnifera against 3rd instar Culex pipiens (Common house mosquito) larvae was evaluated. Methanol extracts had more toxic effects against Cx. pipiens larvae (95–100%, 24 h post-treatment) than aqueous extracts (63–91%, 24 h post-treatment). The methanol extracts of Nerium oleander (LC50 = 158.92 ppm) and Ricinus communis (LC50 = 175.04 ppm) were very effective at killing mosquito larvae, 24 h after treatment. N. oleander (LC50 = 373.29 ppm) showed high efficacy in aqueous plant extracts. Among the different extracts of the five plants screened, the methanol extract of R. communis recorded the highest ovicidal activity of 5% at 800 ppm concentration. Total developmental duration and growth index were highly affected by R. communis and M. azedarach methanol extracts. In field tests it was clear that plant extracts decreased mosquito larval density, especially when mixed with mosquito Bti briquette, with stability up to seven days for N. oleander. GC–MS results showed that the methanol extract had a higher number of chemical compounds, particularly with more terpene compounds. A high-performance liquid chromatography (HPLC) technique was used to detect the existence of non-volatile polyphenols and flavonoids. All five methanol extracts showed high concentrations of active ingredients such as gallic acid, chlorogenic acid (more than 100 μg/ml) and the rosmarinic acid was also found in all the five extracts in addition to 17 active polyphenols and flavonoids presented at moderate to low concentrations. Molecular modeling of 18 active ingredients detected by the HPLC were performed to the vicinity of one of the fatty acid binding proteins of lm-FABP (PDB code: 2FLJ). Rutin, Caffeic acid, coumaric acid and rosmarinic acid which presented densely in R. communis and N. oleander showed multiple and stable intermolecular hydrogen bonding and π–π stacking interactions. The inhibition ability of the fatty acid binding protein, FABP4, was evaluated with remarkable receptor inhibition evident, especially with R. communis and N. oleander having inhibitory concentrations of IC50 = 0.425 and 0.599 µg/mL, respectively. The active phytochemical compounds in the plants suggest promising larvicidal and ovicidal activity, and have potential as a safe and effective alternative to synthetic insecticides.

Climatic effects on aflatoxin contamination of maize

Aflatoxins are frequent contaminants of maize especially in the face of climate change with deleterious health and socio-economic impacts. South Africa is ranked 9th maize exporter globally; hence, insights need to be gained in terms of the maize value chain in South Africa with respect to aflatoxin contamination to evaluate consumers’ exposure. High-performance liquid chromatography (HPLC) technique was used in this study to quantify aflatoxins in South African commercial maize. One thousand and twenty-eight (1028) maize samples were collected across six distinct agro-climatic regions over five harvest seasons (2017 – 2021). A total of 205 samples (19.94 %) were found to be contaminated with aflatoxins, with mean total aflatoxin concentration of 64.17 ppb amongst the contaminated samples, which is above the SA regulatory limit of 20 ppb for animal consumption. The year 2018 recorded the highest mean total aflatoxin value while North-West agro-climatic region had the highest mean total aflatoxin value. Drastic reduction in average rainfall significantly influence aflatoxin contamination of South African maize.

Detection of trace levels of selected allergic chemicals in commercial hair dyes in local market of Jeddah, Saudi Arabia

Hair dyes are now commonly used in Saudi Arabia, and other nations across the world, to cover up grey hairs and/or to modify the natural color of the hair. The principal ingredients of hair dyes are aromatic amines and phenols and which most likely cause allergic reactions, irritated skin, and even cancer in certain cases. Thus, the current study reports the separation and subsequent identification of four chemical constituents namely p-Phenylenediamine (PPD), 3-aminophenol (3AP), resorcinol (RES), and 2-methylresorcinol (2MRS) in 26 commercial hair dyes that represent ten famous brands available in the local market of Jeddah city, Saudi Arabia. High-performance liquid chromatography (HPLC) technique was successfully employed to identify the four chemical compounds using methanol-aqueous solution (10:90 v/v) containing diethanolamine (0.05 %) and ammonium acetate (0.02 M) at pH 5.2 as a proper mobile phase. The column was 150 × 4.6 mm ID and 5 µm Eclipse Plus C18 column and the retention times were 1.26, 3.16, 4.99 and 6.01 min for PPD, 3AP, RES, and 2MRS, respectively. The four standards PPD, 3AP, RES, and 2MRS at 254 nm displayed excellent linear calibration plots in the concentration range 5–100 µg/mL with acceptable correlation coefficients (R2) of 0.9964, 0.9980, 0.9952 and 0.9961, respectively. The low limits of detection (LOD) and quantification (LOQ) based on the standard deviation of the response and the slopes of the plots were found to be equal 7.17, 5.39, 8.33, and 7.47 µg/mL and 23.91, 17.97, 27.75, 24.89 µg/mL for PPD, 3AP, RES, and 2MRS, respectively.

A highly sensitive of electrochemical biosensor based on new aptamer sequence for 17α-ethinylestradiol detection in water

The remarkable features of aptamer as biological agent in detecting various compound with high binding affinity could be useful in monitoring of 17α-ethinylestradiol (EE2). EE2 is considered as an endocrine disrupting compound due its ecotoxicity and has widespread in the aquatic ecosystem due to improper disposal. Hence, there is a pressing requirement for sensitive and selective detection of EE2. In this study, we developed a new electrochemical biosensor based on modified DNA aptamers and gold nanoparticles/poly(n-butyl acrylate-co-N-acryloxysuccinimide) microspheres (Au/P(nBA-NAS)). The DNA aptamers was truncated from a 76-mer sequence to 39-mer sequences via computational method, has showed improved binding affinity and stability for EE2. The biosensor was fabricated by attaching the aptamers to the Au/P(NBA-NAS) microspheres, which is provided a large surface area and enhanced electron transfer for the immobilization and signal amplification of the aptamers. The detection principle of the [Fe(CN)6]−3/−4 redox probe in differential pulse voltammetry (DPV) measurement by the presence of aptamer-EE2 complexes on the electrode surface. The biosensor exhibited a linear relationship between the current decrease and the EE2 concentration in the range of 1 × 10−6 M to 1 × 10−12 M, with a detection limit of 1.7 × 10−13 M. The biosensor exhibited excellent selectivity, repeatability, and recovery for detecting EE2 in real samples, with results that closely matched those obtained using the high-performance liquid chromatography (HPLC) technique. This study provided a promising alternative for developing aptamer-based sensors for onsite environmental monitoring.

Avocado seed extract encapsulated in zein nanoparticles as a functional ingredient

Nano-delivery of natural compounds has gained increasing attention in the food and pharmaceutical ingredients industry. Avocado seed was extracted by a total lipid extraction and the presence of two acetogenin compounds was confirmed by the high-performance liquid chromatography (LC-MS) technique. Then, the avocado seed extract (Avo) was encapsulated into zein nanoparticles by liquid-liquid dispersion and the formation of zein nanoparticles loaded with avocado seed extract (Avo-ZNPs) was confirmed by FTIR analysis. The Avo-ZNPs with various Avo contents showed an average size ranging from 166.9 ± 14.1 to 305.2 ± 16.2 nm with 0.19–0.26 of polydispersity index (PDI), and a surface charge range was −59.5 ± 8.1 to −32.9 ± 0.4 mV, as measured by dynamic light scattering (DLS). The entrapment efficiency (EE) values were up to 82 % and the highest loading capacity (LoC) was 14.8 %. The Avo-ZNPs were found to have significantly higher antioxidant potency compared to the control, as measured by DPPH and FRAP assays. Moreover, the zein nanoparticles were also biocompatible with the acute myeloid leukemia (AML) cell lines, and encapsulated avocado extract induced leukemia cell death. Thus, zein nanoparticles could be a promising delivery system for natural avocado seed extract to be used in the medical and food industries.

Amino‐Functionalized Metal Organic Framework‐Based Dispersive Micro‐Solid‐Phase Extraction Coupled With HPLC for Sensitive Quantification of Bisphenol A and Alkyl Phenols in Aqueous Samples

ABSTRACTA sensitive analytical procedure for simultaneous extraction and determination of bisphenol A and alkyl phenols, namely, 4‐sec‐butylphenol, 4‐tert‐butylphenol, and 4‐tert‐amylphenol from aqueous samples with metal–organic framework (MOF)‐based dispersive micro‐solid‐phase extraction (D‐µSPE) and high‐performance liquid chromatography (HPLC) technique is developed. Sample contaminants were preconcentrated with amino‐functionalized aluminum MOF and later eluted with acetonitrile. The reconstituted sample was subjected to HPLC analysis. Various procedural parameters related to D‐µSPE were optimized. Under optimized preconcentration and chromatographic conditions, calibration curves with excellent linearity (R2 > 0.9986) in the working range of 0.25–100 ng mL−1 were prepared. Limit of detection (S/N = 3) for every analyte within the range of 0.020–0.022 ng mL−1 was obtained. Analyte's recovery 91.16%–97.01% (RSD = 1.02–3.01) for intraday and 89.86%–95.83% (RSD = 1.15–3.13) for inter‐day analysis was obtained from real water samples.

Quality by Design‐Assisted RP‐HPLC Method for Determination of Ritonavir and Darunavir in Pharmaceutical Formulation Using Central Composite Design

ABSTRACTThe quality by design enabled the development of cost‐effective, simple, precise, and rapid Reversed phase‐ high‐performance liquid chromatography techniques for determining ritonavir (RIT) and darunavir (DAR) in the tablet dosage form. Systematic method optimization was performed through central composite design by altering the flow rate and composition of the organic phase in the mobile phase as the critical method parameters for evaluating the necessary analytical attributes, namely, the tailing factor, theoretical plate count, and resolution. The optimal separation was achieved on a column with C18 in nature and dimensions of (250 mm length × 4.6 mm id × 5 µm particle size) using a mobile phase consisting of acetonitrile and water (75:25 v/v) at a flow rate of 0.9 mL/min. Detection was carried out at 247 nm. The retention time of DAR and RIT was 2.939 and 3.537 min, respectively, as per International Council for Harmonization (ICH) guidelines. The developed method was useful for the determination of bulk drug and formulations.

Utilization of silicon dioxide nanoparticles and silicon salts to enhance astaxanthin production in Haematococcus Pluvialis

Haematococcus pluvialis is a type of microalgae that is commercially important as it is the primary source of natural astaxanthin - a potent antioxidant used in nutraceuticals, cosmetics, food, and aquaculture industries. Various nanoparticles and chemicals have been used to stimulate the growth of H. pluvialis to increase astaxanthin production. In this study, silicon nanoparticles were synthesized from tetraethyl orthosilicate (TEOS) and characterized to ensure the pure synthesis of uniform nanocrystals of silicon dioxide. The microalgae were cultivated in optimal Haematococcus medium (OHM) under specific conditions, including a temperature of 25 °C, a pH of 7, and a light intensity of 50 μmol. s−1.m−2 for 12 h of light and 12 h of darkness. To study the amount of viability and astaxanthin production, the microalgae were exposed to different concentrations of silicon, sodium silicate, calcium silicate, and potassium silicate. The highest astaxanthin production (194 mg/g) was obtained after stimulation at 200 μg/ml of silicon compared to the control after 15 days by high-performance liquid chromatography (HPLC) technique. Therefore, it can be concluded that certain concentrations of silicon and silicon salts can be considered a suitable stimulus to produce astaxanthin in the H. pluvialis microalgae. This study highlights the potential of using silicon nanoparticles as a stimulant for astaxanthin production in H. pluvialis, which could have significant implications for the nutraceuticals, cosmetics, food, and aquaculture industries.

The Pre- and Post-Column Derivatization on Monosaccharide Composition Analysis, a Review.

Polysaccharides, as common metabolic products in organisms, play a crucial role in the growth and development of living organisms. For humans, polysaccharides represent a class of compounds with diverse applications, particularly in the medical field. Therefore, the exploration of the monosaccharide composition and structural characteristics of polysaccharides holds significant importance in understanding their biological functions. This review provides a comprehensive overview of extraction methods and hydrolysis strategies for polysaccharides. It systematically analyzes strategies and technologies for determining polysaccharide composition and discusses common derivatization reagents employed in further polysaccharide studies. Derivatization is considered a fundamental strategy for determining monosaccharides, as it not only enhances the detectability of analytes but also increases detection sensitivity, especially in liquid chromatography (LC), capillary electrophoresis (CE), and gas chromatography (GC) techniques. The review meticulously examines pre-column and post-column derivatization techniques for monosaccharide analysis, categorizing them based on diverse detection methodologies. It delves into the principles and distinctive features of various derivatization reagents, offering a comparative analysis of their strengths and limitations. Ultimately, the aim is to provide guidance for selecting the most suitable derivatization approach, taking into account the structural nuances, biological functions, and reaction dynamics of polysaccharides.

Profiling Bioactive Compounds in the Bark of Cinchona officinalis L. and Anti-arthritic Properties Thereof

The bark samples of C. officinalis were collected from The Nilgiris district of Tamil Nadu. The collected samples were processed and extracted using methanol solvent. The extracts showed high yield of secondary metabolites especially alkaloids, phenols, flavonoids, steroids, terpenoids, sterols, quinones and tannins. Alkaloid content was very high in C.officinalis followed by phenol, flavonoid, steroid and Tannin. The secondary metabolites present in C. officinalis (Bark) were isolated, purified, identified and characterized using differential Chromatographic techniques such as TLC, HPLC and GC-MS/ MS. The compounds identified using High Performance Liquid Chromatography (HPLC) technique in bark of C. officinalis in the retention times of 1.750, 2.250, 4.016 and 7.266 minutes were quinine, isoquinidine and cinchonidine. The compounds were then characterized using GC- MS/ MS technique with reference to NIST library. The compounds were eluted from the bark of C. officinalis in the retention time of 9.569, 10.488, 11.814, 13.593, 14.282, 16.542, 16.967, 23.494, 24.954, 25.151, 25.988, 26.752, 26.982, 27.906, 28.277, 31.454, 33.604, and 35.744 minutes. By correlating the retention times with (NIST) mass spectral library the eluted compounds were confirmed as Phthalic acid, Hexadecanoic acid,1,2,3,5-Cyclohexanetetrol, Cinchonab-9-one, 9,12-Octadecadienoic acid (Z,Z)-, Heptadecanoic acid, Quinine, Cinchonine, Cinchonidine, Phenol, Quinine, and gamma.-Sitosterol. The phytochemicals present in the C. officinalis (Bark) samples were evaluated for their biological properties viz., anti-inflammatory activity and anti-arthritic activity in in-vitro conditions. Anti- inflammatory properties of plant samples were tested by protein denaturation method using diclofenac (75 mg/ ml concentration) as positive control. The methanol extract of C.officinalis (Bark) showed anti- inflammatory properties of range between 17.0 and 57.3%. Anti- arthritic activity of bark extract of C. officinalis (75 mg/ ml concentration) was evaluated by albumin denaturation method using diclofenac (75 mg/ ml concentration) as positive control. The methanol extract of C.officinalis (Bark) showed anti- arthritic properties of range between 18.4 and 58.5%. From the study it is understood that the alkaloids and polyphenols present in the methanolic extract of bark of C. officinalis were responsible for their biological properties. Hence, C. officinalis can serve as an alternative to synthetic drugs available in the market to treat arthritis subject to safety (toxicity) studies in humans. Based on the In vitro results, it was confirmed that the bark of C.officinalis possesses comparatively high biological values. Thus an herbal aerosol for arthritis may be formulated using the bark extract of C.officinalis as key ingredient and the therapeutic product will be of cost effective, easy to use and pocket friendly.

Release Kinetics of Sulfentrazone from Chitosan Clay Sulfentrazone Nanocomposite

Introduction: With a rational objective to reduce groundwater contamination from pesticides and thereby reducing ecotoxicological effect of pesticide, present research programme was carried out. Sulfentrazone is a well-known effective pesticide that is used for soybean crops. But at the same time, sulfentrazone is known for its high leaching potential through soil and could lead to ground water contamination Method: So we have synthesized a novel chitosan clay nanocomposites of sulfentrazone at three different concertations of sulfentrazone, 37.64%, 52.44% and 59.85% and its release pattern was studied at three different buffer systems like pH 2, pH 4 and pH 6. Release pattern of Sulfentrazone has been quantified by using High Performance Liquid Chromatography (HPLC) technique. Various mathematical tools have been applied to understand the release kinetics of chitosan clay sulfentrazone nanocomposites Result: Correlation coefficient (R2) of many models has been plotted and the Huguchi model was found to be the most suitable for these nanocomposites. The salient finding of this study is that the release rates of sulfentrazone at pH 4 is 68.39%, 42.62% and 37.75% after 8 hours at three different loading. This release pattern is higher than the release pattern at pH 6 and pH 2. Conclusion: Based on these release data, it is very clear that chitosan clay sulfentrazone nanocomposite can control the release of sulfentrazone at regular soil pH conditions, which is pH 6.

A porous composite sorbent incorporating a metal organic framework and zinc oxide in cryogel to extract carbamate pesticides

A composite sorbent was designed and fabricated by incorporating the Materials of Institute Lavoisier (MIL-101) and zinc oxide (ZnO) into polyvinyl alcohol (PVA) cryogel. The composite sorbent was produced to extract carbamates (carbofuran, carbaryl, isoprocarb and diethofencarb) by in-syringe solid phase extraction (SPE). MIL-101 and ZnO enhanced the adsorption of the carbamates by creating π-π stacking and hydrogen bonding, while porous PVA cryogel acted as a solid support which helped to reduce backpressure in the system. The extraction of the target carbamates was optimized by varying the amount of MIL-101 and ZnO used in the sorbent fabrication, desorption conditions, sample pH, ionic strength, sample flow rate and sample volume. The extracted target carbamates were quantitatively determined using high performance liquid chromatography technique. The developed method exhibited linearity from 1.0 to 150.0 μgL−1 for all four target carbamate pesticides with a limit of detection 0.3 µg/L. The method identified carbamates in fruit juice and white wine, obtaining recoveries from 78.1 to 108.2 % and the relative standard deviation (RSD) lower than 6.3 %. The developed composite sorbent showed good accuracy, is simple to fabricate, works rapidly and can be used for 17 extraction-regeneration cycles.

Comparative study of stem bark and small branches of Streblus asper and anti-carcinogenic and anti-diabetic activity

Background: This study focuses on analyzing stigmasterol, a key compound found in Streblus asper lour., in both stem bark and small branches, and investigates its potential as an alternative source. Objective: To analyze the stigmasterol content in both stem bark and small branches of S. asper through High-Performance Liquid Chromatography (HPLC) techniques. In addition, molecular docking studies are conducted to assess the interaction of stigmasterol with selected anticancer and anti-diabetic target proteins. Materials and Methods: The study involved the comparative analysis of stigmasterol content in stem bark and small branches using HPLC techniques. Molecular docking simulations were performed to evaluate the binding affinity of stigmasterol with target proteins associated with anticancer and anti-diabetic activities. Results: HPLC analysis revealed stigmasterol content of 0.13298% in stem bark and 0.0373% in small branches. Molecular docking simulations demonstrated favorable binding energies (−9.0, −12.2, −9.8, −10.5, and −9.5 kcal/mol) of stigmasterol with selected target proteins. Conclusion: Both stem bark and small branches of S. asper contain stigmasterol, indicating their potential as a source of this compound with promising in silico anticancer and anti-diabetic activity. Utilizing small branches could offer a sustainable alternative while conserving the plant species and its ecological balance. Further validation through in vitro and in vivo studies is warranted to explore the therapeutic potential of stigmasterol fully.

Beltanol Sorption Modelling in the Soil Column using High Performance Liquid Chromatography Technique

Beltanol Sorption Modelling in the Soil Column using High Performance Liquid Chromatography Technique

Development and validation of stability-indicating method of etrasimod by HPLC/DAD/MS/MS technique with greenness profiling

Etrasimod, a novel selective sphingosine-1-phosphate receptor modulator, was recently approved by the U.S. Food and Drug Administration and the European Medicinal Agency for the treatment of moderately to severely active ulcerative colitis in adults. In this research, the forced degradation study as an integral part of drug product and packaging development, which generates data on degradation mechanisms, is published. The development and validation of the stability-indicating method using a superior high-performance liquid chromatography technique coupled with a diode array detector and tandem mass spectrometer was performed to support the forced degradation study and monitor the formation of degradation products. Etrasimod demonstrated good stability under elevated temperature and basic stress conditions, while acidic hydrolysis, oxidative, and photolytic degradation produced eight degradation products. The knowledge of degradation products will be useful in the long-term stability study for establishing the acceptance criteria of etrasimod as a drug substance and dosage form during quality control and stability assessment. The eco-friendliness of the developed forced degradation procedure was evaluated using various greenness appraisal tools. The green metric tools showed that the forced degradation procedure obeys eco-friendly conditions.

A review of food contamination with nitrated and oxygenated polycyclic aromatic hydrocarbons: toxicity, analysis, occurrence, and risk assessment.

Prolonged exposure to polycyclic aromatic hydrocarbons (PAHs) and their derivatives, particularly nitrated polycyclic aromatic hydrocarbons (NPAHs) and oxygenated polycyclic aromatic hydrocarbons (OPAHs), can result in adverse health effects and may carry higher toxicity risks compared to PAHs alone. Various extraction methods have been utilized for PAHs derivatives from food samples. The analytes are then analyzed using gas chromatography/mass spectrometry and high-performance liquid chromatography techniques. PAHs derivatives are increasingly being detected in the environment, prompting scrutiny from numerous researchers. Similarly, their presence in food is becoming a significant concern. The elevated levels of PAH derivatives found in smoked food may result in detrimental dietary exposure and pose potential health hazards. Furthermore, investigating the level of exposure to these contaminants in food is imperative, as their consumption by humans carries inherent risks. Consequently, this review concentrates on the toxicity, analysis, occurrence, and risk evaluation of NPAHs and OPAHs present in food sources.

Validated Chromatography Method for Analysis of Formaldehyde Migration Levels in Bottled Drinking Water

Polyethylene terephthalate (PET) is utilized in the containment of potable water, nonetheless, it is susceptible to impairment due to temperature and duration of storage. Migration of formaldehyde from PET arises as a consequence of thermal deterioration. This study aims to ascertain the extent of formaldehyde transference in PET-contained drinking water of varying condition, subjected to diverse temperature setting and storage durations. An examination into the levels of formaldehyde migration in polyethylene terephthalate (PET) bottled drinking water was effectively carried out employing a validated high-performance liquid chromatography (HPLC) technique. A total of 162 water samples from three different PET bottled water brands sourced from supermarkets in Palu City, Central Sulawesi, Indonesia, underwent analysis. The formaldehyde assessment was executed utilizing a mobile phase composition of methanol:acetonitrile:water (48:12:40 v/v) for 12.97 minutes at a flow rate of 0.8 mL/minute on the 1st day, the 14th day, and the 42nd day while stored at room temperature and exposed to sunlight. Formaldehyde, lacking effective chromophoric entities and not readily ionizable, necessitated derivatization with 2,4-dinitrophenylhydrazine before HPLC analysis. The findings of the study demonstrated exceptional method linearity within the concentration span of 0.5 to 1321 µg/mL, exhibiting a commendable correlation coefficient of 0.999. The limit of detection (LOD) and quantification (LOQ) were determined to be 17.33 and 57.76 µg/mL, correspondingly. Precision evaluations displayed average intraday and interday values of 128.46±3.48% and 103.19±0.12%, respectively (%RSD < 2/3 CV Horwitz ratio). The intraday and interday %recovery values were computed at 97.22±3.48% and 96.83±0.14% (n = 6). The scrutiny of formaldehyde concentrations in the water samples unveiled the absence of formaldehyde migration.

Hyphenation of supercritical fluid chromatography and trapped ion mobility-mass spectrometry for quantitative lipidomics

BackgroundLipidomics studies require rapid separations with accurate and reliable quantification results to further elucidate the role of lipids in biological processes and their biological functions. Supercritical fluid chromatography (SFC), in particular, can provide this rapid and high-resolution separation. The combination with trapped ion mobility spectrometry (TIMS) has not yet been applied, although the post-ionization separation method in combination with liquid chromatography or imaging techniques has already proven itself in resolving isomeric and isobaric lipids and preventing false identifications. However, a multidimensional separation method should not only allow confident identification but also provide quantitative results to substantiate studies with absolute concentrations. ResultsA SFC method was developed and the hyphenation of SFC and TIMS was further explored towards the separation of different isobaric overlaps. Furthermore, lipid identification was performed using mass spectrometry (MS) and parallel accumulation serial fragmentation (PASEF) MS/MS experiments in addition to retention time and collision cross section (CCS). Quantification was further investigated with short TIMS ramps and performed based on the ion mobility signal of lipids, since TIMS increases the sensitivity by noise filtering. The final method was, as an exemplary study, applied to investigate the function of different ceramide synthases (CerS) in the nematode and model organism Caenorhabditis elegans (C. elegans). Loss of three known CerS hyl-1, hyl-2 and lagr-1 demonstrated different influences on and alterations in the sphingolipidome. SignificanceThis method describes for the first time the combination of SFC and TIMS-MS/MS, which enables a fast and sensitive quantification of lipids. The results of the application to C. elegans samples prove the functionality of the method and support research on the metabolism of sphingolipids in nematodes.