High-performance liquid chromatography coupled to Orbitrap mass spectrometry for screening of common new psychoactive substances and other drugs in biological samples.

The complexity of the drug market and the constant updating of drugs have been challenging issues for drug regulatory authorities. With the emergence of new psychoactive substances (NPS) and the nonmedical use of prescription drugs, forensic and toxicology laboratories have had to adopt new drug screening methods and advanced instrumentation. Using high-performance liquid chromatography coupled with Orbitrap mass spectrometry, we developed a screening method for common NPS and other drugs. Two milliliters of mixed solvent of n-hexane and ethyl acetate (1:1, v:v) were added to 500 µL of blood or urine sample for liquid-liquid extraction, and methanol extraction was used for hair samples. The developed method was applied to 3897 samples (including 332 blood samples, 885 urine samples, and 2680 hair samples) taken from drug addicts in a province of China during 2019-2021. For urine and blood samples, the limits of detection (LODs) ranged from 1.68 pg/mL to 10.7 ng/mL. For hair samples, the LODs ranged from 3.30 × 10-5 to 4.21 × 10-3 ng/mg. The matrix effects of urine, blood, and hair samples were in the range of 47.6%-121%, 39.8%-139%, and 6.35%-118%, respectively. And the intra-day precision was 3.5%-6.0% and the inter-day precision was 4.18%-9.90%. Analysis of the actual samples showed an overall positive detection rate of 58.9%, with 5.32% of the samples indicating the use of multiple drugs.

Carcinogenic health outcomes associated with endocrine disrupting chemicals exposure in humans: A wide-scope analysis.

Endocrine-disrupting chemicals (EDCs) are persistent and pervasive compounds that pose serious risks. Numerous studies have explored the effects of EDCs on human health, among which tumors have been the primary focus. However, because of study design flaws, lack of effective exposure levels of EDCs, and inconsistent population data and findings, it is challenging to draw clear conclusions on the effect of these compounds on tumor-related outcomes. Our study is the first to systematically integrate observational studies and randomized controlled trials from over 20 years and summarize over 300 subgroup associations. We found that most EDCs promote tumor development, and that exposure to residential environmental pollutants may be a major source of pesticide exposure. Furthermore, we found that phytoestrogens exhibit antitumor effects. The findings of this study can aid in the development of global EDCs regulatory health policies and alleviate the severe risks associated with EDCs exposure.

[Study on determination methods and analysis of micronutrients in take-away meals].

OBJECTIVE: To comprehensively analyze the trace nutrient contents in take-away meals, the simultaneous detection method of common vitamins in take-away meals were explored based on the samples' matrix, and the content of trace nutrients in take-away meals was analyzed combined with inductively coupled plasma-mass spectrometry(ICP-MS) detection of common elements. METHODS: Fifty-seven take-away meals were collected randomly and analyzed. Vitamins were determined by high performance liquid chromatography-ultraviolet detector tandem fluorescence detector after pretreatment of samples including enzymatic digestion, hydrolysis and extraction. The separation was performed on a C_(18) column(250 mm×4.6 mm, 5 µm) with ion-pair acid reagents as the mobile phase for water-soluble vitamins and methanol for fat-soluble vitamins. Vitamin B_1, vitamin B_2, nicotinic acid, nicotinamide and vitamin A were detected by ultraviolet detector(UVD), while vitamin B_6 and E by fluorescence detector(FLD). Elemental analysis of calcium, magnesium, sodium, potassium, zinc, selenium and copper in the take-away meals was carried out according to GB 5009.268-2016 by ICP-MS to comprehensively evaluate the contents of micronutrients. RESULTS: Through optimization of chromatography and sample pretreatment conditions, the sensitivity of the established detection method can meet the needs of micronutrient evaluation with the detection limits and quantification limits of vitamins in the range of 0.002-0.098 mg/100 g and 0.007-0.327 mg/100 g, respectively. Good precision was obtained(<10%). The spiked recovery rates were 80.5%-103.8%(n=6). The result showed that the contents of micronutrients in take-away meals were generally low. The detection rates of vitamins ranged from 21.1% to 98.2%. CONCLUSION: The proposed method is simple and sensitive, and the contents of vitamins and elements determined were low in the collected take-away meals.

Exploring the relationships between exposure levels of bisphenols and phthalates and prostate cancer occurrence.

We established an ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method for simultaneously analyzing the metabolites of bisphenols and phthalates in urine to identify the associations between these exposure levels and prostate cancer (PCa) based on a case-control study. After purifying urine samples with SPE, 18 metabolites were separated on a C18 column, and MS detection was performed. The UPLC-MS/MS method has been proven effective at evaluating bisphenol and phthalate exposure (0.020-0.20 µg/L of the limits of detection, 71.8 %∼119.4 % of recoveries, 0.4 %∼8.2 % of precision). Logistic regression explored the association between exposure level and PCa in 187 PCa cases and 151 controls. The detection rates of bisphenol A (BPA) and most phthalate metabolites were 100 % ranging from 0.06-46.74 and 0.12-899.92 µg/g creatinine, respectively, while the detection rates of other bisphenols and mono-benzyl phthalate (MBzP) are low, ranging from 0 % to 21.85 %. Correlation analysis of the metabolite levels indicated that the exposure sources of BPA, di-ethyl phthalate (DEP), and di(2-ethylhexyl) phthalate (DEHP) were different, and that the exposure sources of di-n-butyl phthalate (DnBP) and di-isobutyl phthalate (DiBP) may differ between two groups. Logistic regression analysis revealed that BPA (OR<0.45 vs ≥1.43 =10.02) and DEHP exposure (OR<21.75 vs ≥45.42 =48.26) increased the risk of PCa.

The screening method for 39 phytotoxins and mycotoxins in blood and urine with liquid chromatography-high resolution mass spectrometry.

BACKGROUND: Poisonings caused by plant toxins and mycotoxins occur frequently, which do great harm to human health and social public health safety. When a poisoning incident occurs, biological samples are commonly be used to conduct the detection of toxic substances and their metabolites for targeted clinical treatment and incident analysis. OBJECTIVE: To establish an efficient and accurate analysis method of 39 phytotoxins and mycotoxins in blood and urine by high performance liquid chromatography quadrupole tandem orbitrap mass spectrometry (HPLC-Orbitrap MS). METHOD: After 3 mL of methanol being added to 1 mL blood and urine respectively for extraction and protein precipitation, the supernatant was injected into HPLC-Orbitrap MS for analysis. The phytotoxins and mycotoxins were separated by Hypersil GOLD PFP column with gradient elution using methanol-5 mmol/L ammonium acetate as mobile phase. The data were collected in ESI positive ion mode using Full MS/dd-MS2 for mass spectrometry detection. RESULT: The mass database of 39 phytotoxins and mycotoxins was developed, and accurate qualitative analysis can be obtained by matching with the database using the proposed identification criteria. Limit of detections (LODs) were 1.34 × 10-4 âˆ¼ 1.92 ng/mL and 1.92 × 10-4 âˆ¼ 9.80 ng/mL for blood and urine samples, respectively. Limits of quantification (LOQ) of toxins in blood and urine ranged from 4.47 × 10-4 âˆ¼ 6.32 ng/mL and 6.39 × 10-4 âˆ¼ 32.67 ng/mL, respectively. Intra-day relative standard deviations (RSDs) were 0.79 % âˆ¼ 10.90 %, and inter-day RSDs were 1.08 % âˆ¼ 18.93 %. The recoveries can reach 90 % âˆ¼ 110 % with matrix matching calibration curves. CONCLUSION: The established method is simple and rapid to operate, which can complete the sample analysis within 30 min, providing technical support for clinical poisoning treatment and public health poisoning analysis.

4-octyl itaconate inhibits high glucose induced renal tubular epithelial cell fibrosis through TGF-ß-ROS pathway.

Diabetic kidney disease (DKD) is one of the most serious complications of diabetes and has become the leading cause of end-stage kidney disease, causing serious health damage and a huge economic burden. Tubulointerstitial fibrosis play important role in the development of DKD. Itaconate, a macrophage-specific metabolite, has been reported to have anti-oxidant, anti-inflammatory effects. However, it is unknown whether it perform anti-fibrotic effect in renal tubular epithelial cells. In this current study, we observed that in human renal tubular epithelial cells (HK2), high glucose induced an increase in transforming growth factor ß (TGF-ß) production, and upregulated the expressions of fibronectin and collagen I through the TGF-ß receptor as verified by administration of TGF-ß receptor blocker LY2109761. Treatment with 4-octyl itaconate (4-OI), a derivant of itaconic acid, reduced the TGF-ß production induced by high glucose and inhibited the pro-fibrotic effect of TGF-ß in a dose-dependent manner. In addition, we found that 4-OI exerted its anti-fibrotic effect by inhibiting the excessive production of ROS induced by high glucose and TGF-ß. In summary, 4-OI could ameliorate high glucose-induced pro-fibrotic effect in HK2 cell, and blocking the expression of TGF-ß and reducing the excessive ROS production may be involved in its anti-fibrotic effect.

The mixed effect of Endocrine-Disrupting chemicals on biological age Acceleration: Unveiling the mechanism and potential intervention target.

INTRODUCTION: Although previous studies investigated the potential adverse effects of endocrine-disrupting chemicals (EDCs) on biological age acceleration and aging-related diseases, the mixed effect of multiple types of EDCs on biological age acceleration, including its potential underlying mechanism, remains unclear. METHODS: Data from the National Health and Nutrition Examination Survey (NHANES) were used to analyze biological age measures, including Klemera-Doubal method biological age (KDM-BA), phenotypic age, and homeostatic dysregulation (HD). Weight quantile sum (WQS) regression was performed to screen biological age-related EDCs (BA-EDCs) and assess the mixed effect of BA-EDCs on biological age acceleration and aging-related disease. Targets of BA-EDCs were obtained from three databases, while heart aging-related genes were obtained from the Aging Anno database. Protein-protein interaction (PPI) network and MCODE algorithm were applied to identify potential interactions between BA-EDC targets and heart aging-related genes. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis were performed to identify related pathways. RESULTS: This cross-sectional study included 1,439 participants. A decile increase in BA-EDCs co-exposure was associated with 0.31 years and 0.17 years of KDM-BA and phenotypic age acceleration, respectively. The mixed effect of BA-EDCs was associated with an increased prevalence of atherosclerotic cardiovascular disease (ASCVD). Vitamins C and E demonstrated a significant interaction effect on the association between BA-EDCs and KDM-BA acceleration. PPI network and functional enrichment analysis indicated that the AGE-RAGE signaling pathway in diabetic complications was significantly enriched. CONCLUSION: Our results showed that the co-exposure effect of BA-EDCs was associated with biological age acceleration and ASCVD, with the AGE-RAGE signaling pathway being the underlying mechanism. Vitamins C and E may also be an actionable target for preventing EDC-induced biological aging.

Association between nickel exposure and body compositions in the United States: a population-based cross-sectional study.

BACKGROUND: Increasing body fat or decreasing muscle and bone mass were associated with worse health outcomes in the adult population. The effects of nickel exposure on body composition are not known. The aim of the current study was to investigate the relationship between urinary nickel levels and body compositions. MATERIALS AND METHODS: Two thousand seven hundred sixty-two participants were included in the analysis from the National Health and Nutrition Examination Surveys of 2017-2018 after excluding participants who have missing data on urinary nickel and those with missing all body mass component data. We used weighted generalized linear models to explore the relationship between urinary nickel and body mass components under interpolating missing covariable values. Simultaneously, sensitivity analyses and subgroup analysis were conducted to verify stability of analysis result. Curve fitting and saturation effect analysis were used to explore the possible nonlinear relationship between urine nickel and body compositions. RESULTS: Among the 2,762 participants, the average urinary nickel level was 1.58 ug/L. The weighted generalized linear models, the sensitivity analyses and subgroup analyses found no significant linear relationship between urinary nickel and body compositions. For body weight, BMI, TLM, ALM, TRF, TOF and BMC, the urine nickel saturation effect values were 0.76, 0.74, 0.5, 0.67, 0.64, 0.48, and 0.45 ug/L, respectively. For each 1 ug/L rise in urinary nickel levels at levels below the turning point, body weight increases (ß = 9.06, 95% CI = 2.75, 15.36, p = 0.01), BMI increases (ß = 3.20, 95% CI = 1.36, 5.05, p = < 0.001), TLM decreases (ß = -47.39, 95% CI = -97.38, 2.59, p = 0.06), ALM decreases (ß = -37.25, 95% CI = -63.25, -11.24, p = 0.01), TRF increases (ß = 20.68, 95% CI = 1.50, 39.86, p = 0.03), TOF increases (ß = 57.92, 95% CI = -0.12, 115.95, p = 0.05), and BMC decreases (ß = -6.84, 95% CI = -12.64, -1.04, p = 0.02). CONCLUSIONS: In summary, our study demonstrated that a dose-response relationship exists between urinary nickel and body compositions, with a low inflection point level of urinary nickel for the saturation effect.

A simplified D3 -creatine dilution method for skeletal muscle mass determination with dynamic correction of creatinine and D3 -creatinine using ultra-performance liquid chromatography-tandem mass spectrometry.

This study developed a simple method for muscle mass determination based on D3 -creatine dilution by removing the matrix effects of ultra-performance liquid chromatography-tandem mass spectrometry analysis through mutual correction of creatinine and D3 -creatinine. Rats were administered an oral tracer dose of D3 -creatine at age 6 weeks. Creatinine and D3 -creatinine in urine were detected using ultra-performance liquid chromatography-tandem mass spectrometry after diluting 20 times to obtain D3 -creatinine enrichment factor (mole percent excess). The mole percent excess obtained from peak area could be used to calculate muscle mass using the improved formula. The limit of detection was 0.500 ng/mL for D3 -creatinine. Creatinine and D3 -creatinine could be mutually corrected because of the same matrix effect, and D3 -creatine spillage was negligible within 0.22%. Isotopic steady time was consistent with that obtained using conventional methods. Bland-Altman plots demonstrated the satisfying consistency between the proposed method and magnetic resonance imaging. This is a simple and rapid measuring method of muscle mass based on D3 -creatine dilution that requires no accurate quantification of creatinine and D3 -creatinine concentrations and no urine sample collection to obtain D3 -creatine spillage.

Research progress in human biological monitoring of aromatic hydrocarbon with emphasis on the analytical technology of biomarkers.

Aromatic hydrocarbons are unsaturated compounds containing carbon and hydrogen that form single aromatic ring, or double, triple, or multiple fused rings. This review focuses on the research progress of aromatic hydrocarbons represented by polycyclic aromatic hydrocarbons (including halogenated polycyclic aromatic hydrocarbons), benzene and its derivatives including toluene, ethylbenzene, xylenes (o-, m- and p-), styrene, nitrobenzene, and aniline. Due to the toxicity, widespread coexistence, and persistence of aromatic hydrocarbons in the environment, accurate assessment of exposure to aromatic hydrocarbons is essential to protect human health. The effects of aromatic hydrocarbons on human health are mainly derived from three aspects: different routes of exposure, the duration and relative toxicity of aromatic hydrocarbons, and the concentration of aromatic hydrocarbons which should be below the biological exposure limit. Therefore, this review discusses the primary exposure routes, toxic effects on humans, and key populations, in particular. This review briefly summarizes the different biomarker indicators of main aromatic hydrocarbons in urine, since most aromatic hydrocarbon metabolites are excreted via urine, which is more feasible, convenient, and non-invasive. In this review, the pretreatment and analytical techniques are compiled systematically for the qualitative and quantitative assessments of aromatic hydrocarbons metabolites such as gas chromatography and high-performance liquid chromatography with multiple detectors. This review aims to identify and monitor the co-exposure of aromatic hydrocarbons that provides a basis for the formulation of corresponding health risk control measures and guide the adjustment of the exposure dose of pollutants to the population.

Establishment and application of a screening method for 354 organic toxicants in blood and urine with high-performance liquid chromatography-high-resolution orbitrap mass spectrometry.

A rapid and sensitive high-performance liquid chromatography-high-resolution orbitrap mass spectrometry method was developed for the simultaneous screening of 354 organic poisons and metabolites in blood and urine, including drugs, medications, pesticides, rodenticides, veterinary drugs, alkaloids, and mycotoxins with a multi-toxicant chromatography-mass spectrometry information library. The method and library showed good prospects in clinical poisoning screening and forensic toxicological identification. Blood and urine samples were extracted successively with ethyl acetate in acidic and alkaline conditions; then, the extract was blown to nearly dry by nitrogen gas and redissolved with methanol-aqueous solution (v:v, 50:50), and the dissolved solution was analyzed by LC-MS/MS after filtering. Precursor ions' m/z was set for identification, retention time, fragment ions, and isotopic pattern which were used for confirmation. No interference peaks were found in the blank samples, showing good specificity. The LODs of toxicants in urine and blood were 1.00×10-3-50.0 ng/mL and 2.07×10-3-50.0 ng/mL, respectively, while the LOQs were 3.30×10-3-1.67×102 ng/mL and 6.91×10-3-1.67×102 ng/mL. The intra-day precision and inter-day precision of urine samples were 2.31-9.13% and 4.75-12.3%, respectively, which were 1.92-10.8% and 2.01-12.1% in blood samples. The established method was applied to analyze 9 cases of clinical poisoning patients, and bromadiolone, carbofuran, and amanitins were detected, respectively. A total of 382 biospecimens from drug abusers were analyzed with the proposed method, which indicated that some drugs were detected in 62 cases, mainly including methamphetamine, heroin, and MDMA. The results were consistent with the information from traditional liquid chromatography-triple quadrupole mass spectrometry.

Changes in Gel Characteristics, Rheological Properties, and Water Migration of PSE Meat Myofibrillar Proteins with Different Amounts of Sodium Bicarbonate.

The changes in the gel and rheological properties and water-holding capacity of PSE meat myofibrillar proteins with different amounts of sodium bicarbonate (SC, 0−0.6/100 g) were studied. Compared to the PSE meat myofibrillar proteins with 0/100 g SC, the texture properties and cooking yield significantly increased (p < 0.05) with increasing SC; meanwhile, adding SC caused the gel color to darken. All samples had similar curves with three phases, and the storage modulus (G') values significantly increased with the increasing SC. The thermal stability of the PSE meat myofibrillar proteins was enhanced, and the G' value at 80 °C increased with the increasing SC. Because water was bound more tightly to the protein matrix, the initial relaxation times of T21 and T22 shortened, the peak ratio of P21 significantly increased (p < 0.05), and the P22 significantly decreased (p < 0.05), which implied that the mobility of the water was reduced. Overall, SC could improve the thermal stability of the PSE meat myofibrillar proteins and increase the water-holding capacity and textural properties of the cooked PSE meat myofibrillar protein gels.

Associations between urinary concentrations of bisphenols and serum concentrations of sex hormones among US. Males.

BACKGROUND: Bisphenol A (BPA) exposure and its structural analogs (BPS and BPF) might cause endocrine alterations and adverse physiological effects. Few studies to date have directly explored the association between its structural analogs (BPS, BPF) and sex hormones in adult male participants. Therefore, we aimed to assess the associations between BPA, BPS, BPF, and sex hormones in American adult men. METHODS: We used data from the U.S. National Health and Nutrition Examination Survey 2011-2016. We excluded participants without data available on sex hormones and urinary bisphenols. Furthermore, participants consuming sex hormone medications were excluded. Multivariable regression models were performed to assess the association between bisphenols and sex hormones. RESULTS: In this study, 2367 participants were included. Of 2367, in 1575 participants, the data on BPS and BPF were available. We found that a per unit increase in BPF was associated with 0.575 ng/dL higher total testosterone (TT) (Model 2: 95% CI: 0.047, 1.103, P = 0.033). However, there was no significant association between BPA or BPS and TT. Furthermore, increased BPA and BPS levels were associated with higher levels of sex hormone-binding globulin (SHBG) (Model 2: ß = 0.364, 95% CI: 0.158, 0.571; ß = 0.25, 95% CI: 0.071, 0.429, respectively). Additionally, participants in the highest BPA exposure quartile (quartile 4) had 4.072 nmol/L higher levels of SHBG than those in quartile 1 (Model 2: 95% CI: 0.746, 7.397, P = 0.017; P for trend =0.005). Both BPA and BPS were negatively associated with free testosterone (FT, nmol/L) after full adjustment (Model 2, ß = - 0.01%, P = 0.0211, P = 0.0211; Model 2, ß = - 0.01%, P = 0.0258, respectively). However, BPF was positively associated with FT (Model 2, ß = 0.0029%, P = 0.0028). CONCLUSION: Our study indicated that exposure to both BPA and its substitutions could alter sex hormone levels. This finding supports the possibility that human exposure to bisphenols at environmental levels might affect the endogenous hormone balance.

Effect of sodium bicarbonate on techno-functional and rheological properties of pale, soft, and exudative (PSE) meat batters.

In the study, changes in salt-soluble protein (SSP) content, gel properties, rheological characteristic, and microstructure attributes of pale, soft, and exudative (PSE) pork batters with different concentrations of added sodium bicarbonate (0-0.6%) were investigated. The pH, b⁎ value, SSP content, cooking yield, texture properties, emulsion stability, and G' values at 72 °C significantly increased with the increase in sodium bicarbonate, but the texture properties and G' values of the samples with 0.4% and 0.6% did not significantly different, while the a⁎ value significantly decreased. Moreover, a greater G' value at 72 °C was in agreement with a higher hardness value of meat batter. The microstructure of cooked PSE meat batters with 0% and 0.2% sodium bicarbonate had a dense structure, and samples with 0.4% and 0.6% had some large cavities. In conclusion, the use of sodium bicarbonate can enhance the water holding capacity, texture and rheological properties of PSE meat batters by increasing their pH, SSP content, and emulsifying stability.

Association between testosterone and serum soluble α-klotho in U.S. males: a cross-sectional study.

PURPOSE: Testosterone plays a crucial role in males, and the deficiency of testosterone leads to multiple adverse health conditions. Klotho is a recently discovered protein encoded by antiaging gene klotho. Both the levels of testosterone and klotho change with aging, so the relationship between them is worth exploring. The purpose of this study was to investigate whether total testosterone is associated with serum klotho levels in U.S. males aged 40-79 years. METHODS: Included in this study were 3750 male participants from the 2011 to 2016 National Health and Nutrition Examination Survey, aged 40-79 years with included information on klotho and sex hormones. The sex steroid hormone levels and klotho concentrations were assayed in laboratories using the recommended methods according to Nutrition Examination Survey guidelines. The association between sex hormones and klotho was calculated using multivariate linear regression models after adjustment for several possible confounding variables. RESULTS: Among the 3750 participants, the total testosterone concentration was 399.048 ± 184.780 ng/dL, and the testosterone deficiency prevalence was 1160 (30.942%). The geometric mean of serum klotho levels was 791.000 pg/mL. In the adjusted models, klotho increased 0.165 pg/mL for every 1 ng/dL increase of total testosterone (p = 0.004). In addition, estradiol (ß 2.232; 95% CI 0.588-3.876; p = 0.032) and sex hormone-binding globulin (ß 2.013; 95% CI 1.173-2.583; p = 0.002) were also positively associated with klotho concentrations. CONCLUSION: This study reported a significant association between klotho and sex hormones in the U.S. male population. The levels of klotho in men increased with total testosterone, estradiol and sex hormone-binding globulin levels, which may have implications for future research and clinical practice.

[Determination of Haloacetic Acids, Disinfection Byproducts, in Tap Water with Reversed-Phase Ultra-Performance Liquid Chromatography-High Resolution Mass Spectrometry].

Objective: To establish a method for quantitative analysis of haloacetic acids (HAAs), disinfection byproducts, in tap water with reversed-phase ultra-performance liquid chromatography-quadrupole-orbitrap high resolution mass spectrometry. Methods: Tap water samples were collected and 0.70 g/L ascorbic acid was added to eliminate residual chlorine. Then, the water samples were directly injected into the instrument for analysis after filtration. After separation on a pentafluorobenzene (PFP) column with an inner diameter of 1.0 mm at a higher linear velocity and a lower volume flow rate compared with those of a narrow-bore column, nine HAAs, namely, monochloroacetic acid (MCAA), monobromoacetic acid (MBAA), dichloroacetic acid (DCAA), bromochloroacetic acid (BCAA), dibromoacetic acid (DBAA), trichloroacetic acid (TCAA), bromodichloroacetic acid（BDCAA), chlorodibromoacetic acid (CDBAA) and tribromoacetic acid (TBAA), were examined by negative electrospray ionization and full MS/dd-MS 2 acquisition mode. In order to adjust for the matrix effect, matrix matching calibration curves were used to quantitate the nine HAAs. Results: Good linearity was obtained for each of the nine HAAs within their respective linear ranges. The detection limits and quantification limits of the method were 0.020-1.0 µg/L and 0.060-3.0 µg/L. The recoveries were 69.8%-119%. Conclusion: The proposed method showed strengths in separation speed and qualitative accuracy. It did not require for complicated pretreatment procedures and can meet the need of tap water sample analysis.

Apoptosis-Related Signature Predicts Prognosis and Immune Microenvironment Infiltration in Lung Adenocarcinoma.

Lung adenocarcinoma (LUAD), a malignancy with high incidence and mortality rates worldwide, contains multiple genomic and epigenomic abnormalities. And the useful tumor markers associated with these abnormalities need further investigation. Whereas apoptosis is a form of programmed cell death, the expression of apoptosis-related genes in LUAD and its relationship with prognosis is unclear. In the present study, we identified 64 differentially expressed apoptosis-related genes (DEARGs) that were differentially expressed between LUAD tissue and normal lung tissue. Based on these DEARGs, all LUAD cases were classified into two subtypes using The Cancer Genome Atlas (TCGA) cohort to assess the prognostic value of apoptosis-related genes for survival. An 11-gene signature was established by applying the Least Absolute Shrinkage and Selection Operator (LASSO) Cox regression method to construct a multigene prediction model and classify all LUAD patients in the TCGA cohort into high or low AS-score groups. Patients in the low AS-score group had significantly higher survival and prognosis than those in the high AS-score group. Taking the median risk score of the AS-score, LUAD patients in the GSE68465 cohort were divided into two risk groups, low and high. The overall survival (OS) time was longer in the low AS-score group. Combined with clinical characteristics, the AS-score was an independent predictor of LUAD patients. Gene ontology (GO) and Kyoto Encylopedia of Genes and Genomes (KEGG) analyses showed that the differential genes between the two groups were mainly enriched in cellular immunity. Further analysis revealed higher immune checkpoint protein expression and higher tumor mutational burden (TMB) in the high AS-score group, suggesting better efficacy of immunotherapy in the high AS-score group than the low AS-score group. And the high AS-score group was better in chemotherapy and targeted therapy efficiency. In conclusion, the AS-score constructed based on apoptosis-related genes can predict the prognosis of LUAD patients and provide some guidance for the antitumor treatment of LUAD patients.