Analysis Of Complex Samples Research Articles

Physical Activity and Its Relationship With National-Based Examination Results Among Adolescents.

This study investigated the longitudinal relationship between self-reported physical activity and national examination results among adolescents in an upper-middle-income country. This study engaged in a secondary data analysis derived from a closed prospective cohort consisting of 579 students, who were recruited at the age of 13 in 2012 and followed up at ages 15 (2014) and 17 (2016) as part of the Malaysian Health and Adolescents Longitudinal Research Team (MyHeART) study, which was conducted across three states in Peninsula Malaysia. Physical activity levels were evaluated using the Physical Activity Questionnaire, and outcomes were assessed based on the National-Based Examinations at ages 15 (Form 3, Year 9) and 17 (Form 5, Year 11) in Malaysia. A multivariate ordinal regression employing complex sample analysis was applied to ascertain the relationship between physical activity and national examination results. In Form 3 (Year 9), those physically active performed better in Malay Language, English Language, Mathematics and Science. Those physically active in Form 5 (Year 11), performed better in Modern Mathematics, Chemistry, and Principles of Accounting. Longitudinally, there was an increase in the overall percentage of those who were overweight and obese and an increase in those with suboptimal dietary and iron intake. This study has shown that those physically active students fared better in several subjects in the national-based examinations. Suitable physical activity intervention should be tailored accordingly to support adolescents' optimum achievement in academia.

DeiT and Image Deep Learning-Driven Correction of Particle Size Effect: A Novel Approach to Improving NIRS-XRF Coal Quality Analysis Accuracy

Coal, as a vital global energy resource, directly impacts the efficiency of power generation and environmental protection. Thus, rapid and accurate coal quality analysis is essential to promote its clean and efficient utilization. However, combined near-infrared spectroscopy and X-ray fluorescence (NIRS-XRF) spectroscopy often suffer from the particle size effect of coal samples, resulting in unstable and inaccurate analytical outcomes. This study introduces a novel correction method combining the Segment Anything Model (SAM) for precise particle segmentation and Data-Efficient Image Transformers (DeiTs) to analyze the relationship between particle size and ash measurement errors. Microscopic images of coal samples are processed with SAM to generate binary mask images reflecting particle size characteristics. These masks are analyzed using the DeiT model with transfer learning, building an effective correction model. Experiments show a 22% reduction in standard deviation (SD) and root mean square error (RMSE), significantly enhancing ash prediction accuracy and consistency. This approach integrates cutting-edge image processing and deep learning, effectively reducing submillimeter particle size effects, improving model adaptability, and enhancing measurement reliability. It also holds potential for broader applications in analyzing complex samples, advancing automation and efficiency in online analytical systems, and driving innovation across industries.

Sulfamethoxazole Detection in Milk Using a Carbon-Based Printed Electrode: Enhanced Selectivity and Response Stability by Pulse-Amperometry

Abstract A simple, low-cost, and lab-made carbon-based electrode was developed for the fast and selective determination of sulfamethoxazole (SMX) in milk samples, requiring only minimal sample preparation (dilution in supporting electrolyte). A custom-made conductive ink (composed of glass varnish, graphite, acetone) was applied to a plastic surface to fabricate a flow-through amperometric sensor integrated into a portable Batch Injection Analysis (BIA) system. This method enhanced selectivity and reduced electrode contamination. The optimized pulsed amperometric waveform conditions included two detection pulses (+1.0 V and +1.3 V) and two cleaning pulses (+1.5 V and -1.5 V), resulting in a linear response from 1.0 to 20.0 μmol L⁻¹, with a detection limit of 0.31 μmol L⁻¹. The stability and reproducibility of the method were confirmed, exhibiting low relative standard deviations (RSD ≤ 8.3%). The system exhibited excellent recovery for spiked milk samples at concentrations of 5.0 μmol L⁻¹ (68 ± 7%), 10.0 μmol L⁻¹ (103 ± 7%), and 20.0 μmol L⁻¹ (115 ± 7%), demonstrating high accuracy and minimal matrix interference. This approach offers a rapid, accurate, and reliable method for the analysis of complex samples, particularly for onsite detection of SMX in milk.

The role of different health information sources in moderating the impact of health literacy on health-related quality of life: evidence from a population-based study in Korea.

Health literacy is a key aspect of healthy living and is widely recognized as a crucial determinant of health outcomes and disparities. Health literacy enables individuals to make informed decisions by accessing, understanding, and utilizing health-related information effectively. Access to and use of health information are essential for optimal health outcomes. This study explores whether different health information sources, such as active, interpersonal, and passive sources, moderate the relationship between health literacy and health-related quality of life (HRQoL). This study analyzed data from the 2021 Korea Health Panel (Version 2.1) including 4164 eligible samples. Health literacy was assessed using the Korean version of the European Health Literacy Survey Questionnaire. Complex sample analysis was used to compute descriptive statistics of the study variables. To determine the moderating effects of health information sources, this study used Hayes's PROCESS macro (Model 1). Among the weighted sample of 16,351,227 participants, 76.1% used active sources to obtain health information, whereas 13.5% and 10.5%, respectively, used interpersonal and passive sources. Regression analysis showed that the moderating effects of health information sources were positively significant. The associations between health literacy and HRQoL were stronger in the interpersonal source group compared to the active or passive source groups. This study highlights the moderating role of interpersonal health information sources in enhancing the relationship between health literacy and health-related quality of life. Interventions targeting interpersonal communication channels may be effective in improving health outcomes, particularly among populations with limited health literacy.

Raman measurements using an acousto-optic tunable filter spatial heterodyne Raman spectrometer with an echelle-mirror structure

This study presents an acousto-optic tunable filter technology-based echelle-mirror spatial heterodyne Raman spectrometer (AOTF-EMSHRS) that integrates echelle gratings with mirror spatial heterodyne detection. The instrument uses the grating’s high resolution and the AOTF’s rapid wavelength selection capability to optimize the optical path through a mirror design. This results in a high signal-to-noise ratio (SNR), high spectral resolution, and broad wavelength range measurements. After calibration, the theoretical resolution reached 1.53 cm−1, with a single-order spectral detection range of 1574.3 cm−1. The spectral detection range spans from 100 cm−1 to 4397 cm−1. Experimentally, we detected and analyzed various organic and inorganic substances and solutions. We compared EMSHRS performances with and without the AOTF and found that the SNR of the AOTF-EMSHRS system has improved by at least twofold. Additionally, we measured solutions with different molar concentrations, various sulfate mixtures, and mixtures in transparent containers made from different materials, obtained comprehensive spectral information, and conducted detailed analyses. The AOTF-EMSHRS demonstrated excellent measurement performance during complex sample detection and analysis.

TDDA: A Targeted Data-Dependent Acquisition Mode for Rapid Screening of Targets in Complex Matrices.

Miniaturized mass spectrometers offer significant potential for in situ analysis due to their high specificity and portability. In traditional data-dependent acquisition (DDA) mode, precursor ions for tandem analysis are selected based on the full-scan mass spectrum. However, in situ applications often require the direct analysis of complex samples without extensive sample pretreatment, making them susceptible to chemical noise that can result in false negatives. To address this challenge, we propose a targeted data-dependent acquisition (tDDA) mode that substantially improves the accurate detection of target compounds in complex matrices. Unlike conventional DDA, the tDDA method eliminates reliance on the full-scan mass spectrum, where signals of interest are often obscured by matrix effects. This approach leverages sine amplitude modulation of sinusoidal frequency modulated (SAM-SFM) waveforms technology, which enables the real-time generation of isolated waveforms, allowing tDDA to achieve parallel, high-speed screening. Additionally, targeted automatic gain control (AGC) technology enhances the detection of low-concentration analytes, further reducing the false-negative rate. The tDDA mode was successfully integrated and validated on a modified "Brick" miniaturized ion trap mass spectrometer. Experimental results demonstrated its capability to detect low concentrations of illicit drugs spiked in blood and saliva samples, highlighting its potential for effective in situ screening.

Quasi-Simultaneous Identification of Polar and Neutral Lipids in Mass Spectrometry by kHz Switching of Electrospray and Plasma Ionization.

The identification of polar and neutral lipid species as biomarkers in complex biological samples is a key task in clinical and life sciences. Electrospray and plasma-based ionization techniques are necessary to cover the full range of lipidomes, owing to their limited molecular polarity ranges. However, combining both to generate hybrid spectra is difficult without averaging spectra, as electrospray and plasma sources operate under vastly different conditions. Their electric fields also interfere, resulting in a mutual destabilization of the ionization processes. Herein, a heated nanoelectrospray is combined with a flexible microtube plasma using a rapid (kHz range) switching process (heated nESI-sFμTP) to generate quasi-simultaneous ionization. This approach loads the ion trap with polar and less-polar ions during each injection cycle, generating hybrid spectra without averaging it. The performance of the quasi-simultaneous approach is investigated in positive ion mode, comparing it with conventional ion sources through the analysis of complex lipid liver and heart samples. While no improvements are observed in negative ion mode, the novel quasi-simultaneous approach shows great potential for analyzing complex samples in positive ion mode. The combined heated nESI-sFμTP exceeds the molecular polarity range of individual sources, offering excellent ionization efficiency and MS2 capabilities.

Efficient adsorption and detection of steroid hormones in foods through the combination of novel magnetic TAPB-COF materials with click isotope probes.

Matrix effects pose a significant challenge in food analysis for the quantitative analysis of complex food samples. Herein, a novel magnetic covalent organic framework nanocomposite and the copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC) click reaction-based stable isotope labeling (SIL) method were presented for highly selective and sensitive detection of steroid hormones in food samples using HPLC-MS/MS. The nanocomposite, Fe3O4@TAPB-COF, with acore-shell structure exhibited high adsorption capacities for steroid hormones. Combined with a SIL method based on the CuAAC click reaction, steroid hormones were accurately quantified in food samples with high sensitivity and selectivity. A pair of SIL agents, N-(2-azidoethyl)aniline (d0-NAEA) and d5-N-(2-azidoethyl)aniline (d5-NAEA), was synthesized to label steroid hormones in the samples and standard solutions, respectively. The labeling reaction is highly specific, and the formation of the derivatives is easily ionized by MS, thus overcoming matrix effects. More surprisingly, the ionization efficiency of steroid hormones increased by a factor of 4 to 56, with matrix effects ranging from 87.3 to 99.3%. Under optimal conditions, this method exhibited a low limit of detection (LOD) ranging from 0.1 to 2.6 μg L-1 and overcame the interference of matrix effects for trace-level steroid hormone analysis in foodstuffs.

Smokers’ perceived cancer risks: attributions of the risks and the roles of risks in planning to quit smoking

ABSTRACT This study proposed that smokers’ perceived cancer risks differ emotionally and cognitively; the former is based on perceived smoking-related causes, while the latter is based more on perceived non-smoking related causes. It further examined the role of perceived reasons for cancer risk, as well as perceived risks, in planning smoking cessation. The study drew a sample of daily smokers, intermittent smokers and previous smokers (as a reference category) from the Health Information National Trends Survey (HINTS). It used complex sample analysis through the SPSS package to run a series of regression models. In the general linear model with the dependent variable of cancer worry, the cancer worry was projected from perceived smoking-related causes more among previous smokers than intermittent smokers, revealing a pattern of self-serving assessment of cancer risks among intermittent smokers. Intermittent smokers were more pessimistic (perceived non-smoking-related causes) than previous smokers about the perceived likelihood of cancer. In the logistic regression model with the dependent variable of planning to quit smoking, pessimistic daily smokers were less likely to plan on quitting than intermittent smokers, though daily smokers who felt a greater likelihood of cancer risk did plan on quitting. Participants’ assessment of cancer risks from perceived non-smoking-related reasons implies that one’s smoking habit plays a minimal role in perceiving health statuses.

Protein Identification Improvement in Complex Samples Using Higher Frequency MS Acquisition and PEAKS Software

Protein identification in complex biological samples using the shotgun mode of LC-MS/MS is typically enhanced by employing longer LC columns and extended gradient times. However, improved identification rates can also be achieved by optimizing MS acquisition frequencies and employing advanced software, without increasing analysis time, thus maintaining the throughput of the method. To date, we found only one study in the literature examining the influence of MS acquisition frequency on protein identification, specifically using two ion trap mass spectrometer models. This study aims to address the gap by analyzing the impact of MS acquisition tuning of the QTOF instrument on the analysis of complex samples. Our findings indicate that increasing acquisition frequency generally improves protein identification, although the extent of improvement depends on the sample type. For CHO cell lysates, protein identifications increased by over 10%, while E. coli and albumin-depleted plasma samples demonstrated gains of 3.6% and 2.6%, respectively. Higher contributions to protein identification were also achieved with extended LC gradients, resulting in improvements of 21.6% for CHO, 18.2% for E. coli, and 10.3% for plasma. Moreover, enabling PEAKS’ deep learning feature significantly boosted identifications, with increases of 22.9% for CHO, 23.2% for E. coli, and 9.2% for plasma.

Recent advances and application of liquid chromatography in pharmaceutical industry

Liquid chromatography (LC) and its associated techniques are essential in the pharmaceutical industry for optimizing drug formulations, ensuring product quality, and meeting regulatory standards. Thin Layer Chromatography (TLC) is widely used for rapid screening and chiral separations in early-stage development due to its simplicity and cost-effectiveness. High-Performance Liquid Chromatography (HPLC) remains the gold standard for routine analysis, offering high resolution and reproducibility for complex sample analysis and quantification of active pharmaceutical ingredients (APIs). Ultra-Performance Liquid Chromatography (UPLC) builds on HPLC, providing faster analysis, higher sensitivity, and greater efficiency, making it ideal for high-throughput testing. Supercritical Fluid Chromatography (SFC) is increasingly used for separating thermally labile and polar compounds, offering advantages in solvent usage and analysis time. This review will discuss the evolution of these chromatographic techniques and their critical role in optimizing pharmaceutical processes, ensuring product quality, and facilitating regulatory compliance throughout the drug development lifecycle.

Calixarene-Based Magnetic Nanosponge Decorating AgNPs for Rapid and Selective Surface-Enhanced Raman Scattering Analysis in Complex Samples.

Rapid and accurate analysis of trace targets in complex samples remains an enormous challenge. Herein, the calix[x]arene-based magnetic cross-linked polymer decorating AgNPs, abbreviated Fe3O4-CXA-DAB@AgNPs nanosponge, was developed for fast surface-enhanced Raman scattering (SERS) analysis in complex samples. The Fe3O4-CXA-DAB@AgNPs nanosponge surface was constructed by high-density CXA units with special cavity size and structure, which could selectively recognize and enrich targets to the sensing surface by the host-guest effect and molecule interactions. The Fe3O4-C4A-DAB@AgNPs showed significant SERS enhancement to choline chloride (ChCl) and succinylcholine chloride (SCC) with an enhancement factor (EF) of 2.9 × 107 and 6.3 × 106, respectively. The Fe3O4-C6A-DAB@AgNPs exhibited high SERS activity to thiabendazole with an EF of 7.6 × 106. Introducing recognition-enrichment-separation with SERS sensing, the nanosponge could achieve rapid enrichment sensing of targets within 6-8 min. Also, the Fe3O4-CXA-DAB@AgNPs nanosponge exhibited good stability for rapid detection with relative standard deviations less than 6.3% for intra-batch (n = 25) and 6.8% for inter-batch (n = 15). Benefiting from these merits, the Fe3O4-C4A-DAB@AgNPs was employed for fast SERS analysis of ChCl and SCC in real samples. The limits of detection were 0.62 μg/L for ChCl and 2.0 μg/L for SCC. ChCl was found in feed sample with recoveries of 85.3-108%, and SCC was found in serum samples with recoveries of 85.7-111%. The methods provided a significant reference for the selective analysis of targets by regulating the calix[x]arenes cavity size to satisfy different molecules and rapid quantification strategy by integrating sample pretreatment technology with sensing detection all-in-one.

Inadequate toothbrushing practice and associated factors among in-school adolescents in Malaysia: Findings from Global School Health Survey (GSHS) 2017.

Inadequate toothbrushing practice is define as brushing teeth less than two times per day. Inadequate toothbrushing during adolescence can lead to oral health problems and disease burden in adults. Moreover, inadequate practice can lead to low quality of life and inadequate self-esteem. This study aimed to determine the prevalence of inadequate toothbrushing practice among adolescents aged 13 to 17 years in Malaysia and its association with sociodemographic and other related risky lifestyles. This study was part of a national cross-sectional study, Global School Health Survey 2017. 27,497 students were agreed to participate in this study, with response of 89.2%. A validated self-administered bilingual, comprised of topics related to sociodemographic as well as adolescent health and risky lifestyles; substance use (alcohol, drug, smoking cigarettes), eating patterns, hygiene (inclusive of oral and hand hygiene), mental health status, lack of peer and parental/guardian support, truancy, physical activity, and body mass index (BMI). Analysis was performed using IBM SPSS for Windows version 26.0 involving complex sampling analysis and logistic regression. A total of 12.7% (95% CI: 11.8-13.6) of in-school adolescents had inadequate toothbrushing practices. Higher prevalence of inadequate toothbrushing were found among male, Indian, had ever drug use, had three or more lack of protective factors and had inadequate hand hygiene practices. Adolescents who had inadequate toothbrushing were significantly higher odd among males, Indian ethnic, ever drug use, inadequate hand hygiene practices and adolescents who had three or more lack of peer and parental/guardian support. Approximately 1 out of 10 adolescents had inadequate toothbrushing practices with several factors associated, such as male gender, Indian ethnicity, inadequate hand hygiene, ever drug use and lack of protective factors are identified to be associated. By emphasizing the significance of frequent brushing, we can encourage positive changes and reduce the burden of preventable dental problems on adolescents.

Exploring the diffusion of DNA strands into nanoporous structures for establishing a universal electrochemical biosensor.

The development of universal electrochemical sensing platforms with high sensitivity and specificity is of great significance for advancing practical disease diagnostic methods and devices. Exploring the structural properties of electrode materials and their interaction with biomolecules is essential to developing novel and distinctive analytical approaches. Here, we innovatively investigated the effect of DNA length and configuration on DNA molecule transfer into the nanostructure of a nanoporous gold (NPG) electrode. The NPG electrode can not only distinguish and quantify short DNA strands but can also prevent the diffusion of long DNA, thereby minimizing or eliminating background interference. Leveraging these findings, we developed a universal DNA-based NPG electrochemical biosensing platform for the detection of different types of biomolecules. As a proof-of-concept, this sensing platform was integrated with nuclease-assisted target-recycling recognition and amplification reactions to achieve sensitive and specific detection of single-stranded DNA, microRNA-21, and carcino-embryonic antigen, with detection limits of 4.09, 27.4, and 0.28 fM, respectively. The demonstrated universality, sensitivity, specificity, and capability for analyzing complex samples ensure a comprehensive and robust detection approach for nucleic acid-based molecular diagnosis.

Precise Light-Driven Polarity of Stationary Phase for Regulating Gradient Separation of Liquid Chromatography.

Generally, the traditional stationary phase for liquid chromatography is the key part, but with an in situ immutable property, leading to many separation limitations. Based on the former exploration of photosensitive gas chromatography, we successfully prepared a photosensitive monolithic capillary silica column with high light transmission, taking advantage of the reversible cis-trans isomerism of azobenzene. And the cis-trans isomerism has launched an effective, reversible, and precise control on the liquid chromatographic retention behavior just by photoinduction according to the theoretical basis of a good correlation between photoinduction time, trans-azobenzene ratio, and chromatographic retention factor (k) (R2 > 0.9586). In this system, the plausible control mechanism of stationary phase's polarity is the synergistic effect of the self-molecular polarity difference and the occupation (or release) of polar groups on the stationary phase surface by cis-trans isomerism. Furthermore, a "light control-time ratio cycle" strategy was first reported to maintain an arbitrary ratio of trans-azobenzene corresponding to the polarity gradient of the stationary phase during the whole chromatographic separation process, which is verified by a close correlation of the retention time of the targets and the ratio of light-controlled time (R2 > 0.9977). The "gradient elution" of the targets was also surprisingly realized due to the gradient regulation of stationary phase's polarity by the programmatic control of alternate light induction and time ratio. This work further advances the practical significance of photosensitive chromatography in "one column for multiple columns", even "one column for multidimensional chromatography", and truly provides research foundation for its development in the separation and analysis of complex biological samples.

Association between Age-Related Macular Degeneration and Arthritis: Data from the Korean National Health and Nutrition Examination Survey for 2017 and 2018

Purpose: We examined the association between age-related macular degeneration (AMD) and arthritis.Methods: Using data from the Korea National Health and Nutrition Examination Survey for 2017 and 2018, we conducted a complex sample analysis of 6,993 individuals with recorded information on AMD, as well as the diagnosis and treatment of osteoarthritis (OA) and rheumatoid arthritis (RA). We compared the diagnosis and treatment of arthritis between the AMD and control groups using logistic regression analysis, with a specific focus on the treatment among patients with arthritis.Results: In the AMD group (n = 1,118) and the control group (n = 5,875), univariate logistic regression analysis showed substantial differences in the diagnosis and treatment of OA and RA. However, after adjusting for age, alcohol consumption, diabetes mellitus, and hypertension in multivariate logistic regression analysis, these differences were no longer substantial. Among patients with OA (n = 246 in the AMD group and n = 821 in the control group), there was a significant association between AMD and OA treatments (odds ratio 1.511, 95% confidence interval 1.051-2.172).Conclusions: Patients diagnosed with and treated for OA had a higher likelihood of concurrent AMD than those who did not receive treatment. Therefore, ophthalmic examinations and closer monitoring are recommended for these patients.

Truancy among School-Going Adolescents in Malaysia and Its Associated Factors: Findings from the National Health and Morbidity Survey 2022

Background: Truancy is correlated with variety of unfavorable outcomes that can negatively impact adolescents’ development and well-being. We investigated the prevalence of truancy and its associated factors among school-going adolescents in Malaysia in 2022. Methods: We used secondary data from the National Health and Morbidity Survey 2022. It is a cross-sectional study with a multistage stratified cluster sampling study design including 32,290 students aged 13 to 17 years old. It utilized the self-administered questionnaire from the validated Malaysian Global School-based Health Survey (GSHS). The associations between the truancy and its associated factors were examined using multivariate logistic regression, a complex sample analysis with sampling weightage. Results: The prevalence of truancy was 25.6% (95% CI=24.25, 26.98). In the multivariate analysis, truancy was significantly associated with older age groups (P<0.001), adolescents with separated/ divorced/ widowed parents (P<0.001), those with current any tobacco product use (P<0.001), those with ever drug use (P<0.001), those who have been physically attacked (P<0.001) and being bullied (P<0.001). Conclusion: Gender, age, parent marital status, and adolescents with risk behavior were associated with truancy. This information may provide evidence for the implementation of effective prevention and intervention strategies to reduce truancy among these school-going adolescents.

Comprehensive and Sensitive Analysis of Total PAEs Using a Label-Free Zero-Voltage Photoelectrochemical Biosensor.

The sensing of phthalate esters (PAEs) is vital for people's health and environmental protection. This study aimed to develop a highly sensitive and selective photoelectrochemical (PEC) biosensor for PAEs analysis in complex samples. The biosensor is based on a CdS nanoparticle/TiO2 nanotube (CdS NP/TiO2 NT) electrode substrate and a truncated PAEs aptamer (PAEs-apt). By exploiting spatial variations in the potential resistance of the sensing interface, the biosensor achieved superior sensitivity in determining the concentration of PAEs compared to the SELEX aptamer. It exhibited a linear correlation in the range of 0.005 to 1 ng/mL with a detection limit of 1.67 ng/L. Furthermore, the biosensor displayed excellent selectivity for PAEs, with an analysis error factor below 0.277 when the concentration of interfering species was 100 times that of the target. The high performance of the biosensor was attributed to the excellent photoelectronic properties of CdS NPs/TiO2 NTs, high density of PAEs-apt for PAEs, high affinity of PAEs-apt for PAEs, and specific recognition of PAEs. Notably, this PEC biosensor could be used for the PAEs assay in urine and water samples, providing a sensitive and simple analytical method for detecting the same class of compounds with similar chemical structures in complex samples.

Exploring the factors associated with prelacteal feeds in Papua New Guinea: a population-based survey

BackgroundPrelacteal feeding disrupts early breastfeeding initiation and exclusive breastfeeding, and increases the risk of childhood illnesses and under-five mortality. Despite its negative health outcomes, newborns are given prelacteal feeds in...

Four-Dimensional Lipidomic Analysis Using Comprehensive Online UHPLC × UHPSFC/Tandem Mass Spectrometry.

Multidimensional chromatography offers enhanced chromatographic resolution and peak capacity, which are crucial for analyzing complex samples. This study presents a novel comprehensive online multidimensional chromatography method for the lipidomic analysis of biological samples, combining lipid class and lipid species separation approaches. The method combines optimized reversed-phase ultrahigh-performance liquid chromatography (RP-UHPLC) in the first dimension, utilizing a 150 mm long C18 column, with ultrahigh-performance supercritical fluid chromatography (UHPSFC) in the second dimension, using a 10 mm long silica column, both with sub-2 μm particles. A key advantage of employing UHPSFC in the second dimension is its ability to perform ultrafast analysis using gradient elution with a sampling time of 0.55 min. This approach offers a significant increase in the peak capacity. Compared to our routinely used 1D methods, the peak capacity of the 4D system is 10 times higher than RP-UHPLC and 18 times higher than UHPSFC. The entire chromatographic system is coupled with a high-resolution quadrupole-time-of-flight (QTOF) mass analyzer using electrospray ionization (ESI) in both full-scan and tandem mass spectrometry (MS/MS) and with positive- and negative-ion polarities, enabling the detailed characterization of the lipidome. The confident identification of lipid species is achieved through characteristic ions in both polarity modes, information from MS elevated energy (MSE) and fast data-dependent analysis scans, and mass accuracy below 5 ppm. This analytical method has been used to characterize the lipidomic profile of the total lipid extract from human plasma, which has led to the identification of 298 lipid species from 16 lipid subclasses.