Objective:To analyze the effect of acidic or alkaline diluents of the direct dilution method on the results of multiple elements measurement in whole blood by inductively coupled plasma mass spectrometry (ICP-MS) and to explore the possibility whether the two diluents can be substituted for each other in elemental measurement results.Methods:A total of 162 human whole blood samples collected from the National Human Biomonitoring Programme in August 2018 were used for dilution with different diluents followed by centrifugation, then the supernatants of the samples were measured by ICP-MS. The methodological characteristics of the two pre-treatment methods including acidic diluent (0.1% nitric acid+0.01% tralatone solution) and alkaline diluent (0.05% n-butanol+0.01% tralatone+1% ammonium hydroxide solution) were evaluated separately. Spearman correlation coefficient analysis was used for the correlation of 19 elements results in whole blood measured by 2 diluents, then, Passing-Bablok linear regression and Bland-Altman plots were used to evaluate the consistency of the 19 elements results in 162 whole blood samples between the two diluents.Results:The methodological data of 19 elements using the two diluents were good, with the limits of quantification (LOQ) of the 19 elements were 0.1-15.8 μg/L for acidic diluents and 0.3-19.2 μg/L for alkaline diluents, and the linear correlation coefficients of the standard curves of the 19 elements using the acidic and alkaline diluents were all≥0.995. Except for strontium, cadmium, tin, and thallium, the recovery percents of the 19 elements were all in the range of 80%-120%, and for all elements the total coefficients of variation of within-and between-run in the acidic and alkaline diluents were 0.5%-12.4%. The correlation coefficients of the two diluents for the measured values of chromium, manganese, cobalt, zinc, copper, arsenic, selenium, strontium, molybdenum, silver, cadmium, antimony, barium, mercury, and lead were relatively strong ( R2>0.8), while the correlation coefficients of vanadium, nickel, tin, and thallium were relatively weak ( R2<0.8). For the vanadium, cadmium, tin, barium, and mercury, 95% confidence intervals of slopes were<1. The 95% confidence intervals of intercepts of chromium, nickel, arsenic, silver, barium, and mercury contain point 0. The Bland-Altman plot showed that vanadium, chromium, arsenic, strontium, silver, cadmium, tin, and mercury have good consistency in using acidic and alkaline diluents. Conclusion:The results of the mean values measured with the 2 diluents differed among different elements and could not be completely substituted.

Alzheimer's disease （AD） is a common degenerative disease of the central nervous system in the elderly， with memory impairment and behavioral changes as the main clinical manifestations. Modern research has demonstrated that many herbs with both medicinal and edible values have anti-oxidation and anti-aging activities. In addition， these herbs are naturally safe and play a role in disease prevention and health care. The 110 medicinal and edible herbs announced by the National Health Commission of the People's Republic ofChina in 2021 were studied. The relevant papers published in the last five years were searched against CNKI， VIP， Wanfang Data， PubMed and other databases. The effects， mechanism， and active ingredients of the medicinal and edible herbs against Alzheimer's disease were summarized. The results showed that more than 30 herbs including Ginseng Radix et Rhizoma， Curcumae Longae Rhizoma， Astragali Radix， Corni Fructus， Gastrodiae Rhizoma， Angelicae Sinensis Radix， Cistanches Herba， Croci Stigma， Glycyrrhizae Radix et Rhizoma， Ganoderma and their active ingredients were effective in the prevention and treatment of Alzheimer's disease. Among them， ten herbs that met the requirements were screened out for analysis. The medicinal and edible herbs and their active ingredients can act on multiple targets and treat Alzheimer's disease via multiple signaling pathways such as nuclear factor-κB （NF-κB）， mitogen-activated protein kinase 5 （MEK5）/extracellular signal-regulated kinase 5 （ERK5）， cytochrome C （CytC） and cysteine aspartate-specific protease （Caspase）-3/（Caspase）-9， Wnt/β-catenin， and brain-derived neurotrophic factor （BDNF）/tyrosine kinase receptor B （TrkB）/phosphatidylinositol 3-kinase （PI3K）/protein kinase B （Akt）， thus improving learning， cognitive ability， and memory ability. Most of the medicinal and edible herbs have the tropism to the heart， spleen， liver， and kidney meridians and tonifying effect.

Background Previous research on chlorinated paraffins (CPs) in fine particulate matter (PM_2.5) has predominantly focused on short- and medium-chain chlorinated paraffins (SCCPs and MCCPs), and few studies could simultaneously determine short-, medium-, and long-chain chlorinated paraffins (LCCPs). Simultaneous extraction and determination of SCCPs, MCCPs, and LCCPs in PM_2.5 could provide technical support for their environmental monitoring and human health risk assessment. Objective To establish a method based on QUEChERS pretreatment method in conjunction with ultra-performance liquid chromatography-quadrupole/orbitrap high resolution mass spectrometry for simultaneously determining the levels of SCCPs, MCCPs, and LCCPs in PM_2.5. Methods The extraction solvents, extraction salts, and extraction steps of a QuEChERS method were optimized. The extraction efficiencies of the target substances were compared under 4 extraction solvents [acetonitrile, dichloromethane, and n-hexane solvents in sequence; acetonitrile: dichloromethane: n-hexane = 1: 1: 2 (v/v/v) mixed solvent; 1% acetic acid-acetonitrile: dichloromethane: n-hexane = 1: 1: 1 (v/v/v) mixed solvent; acetonitrile: dichloromethane: n-hexane = 1: 1: 1 (v/v/v) mixed solvent], 2 dehydrated salts (anhydrous MgSO₄+NaCl and anhydrous Na₂SO₄+NaCl), 2 purification salts (C18 and PSA), and 4 vortex time (5, 7.5, 10, and 12.5 min) conditions. Then internal standard was utilized to estimate linear range and detection limit of the refined QuEChERS approach. Results The linearities of SCCPs, MCCPs, and LCCPs were good in the range of 10~1000 ng·mL⁻¹ with the correlation coefficients all greater than 0.96. The method detection limits (MDLs) ranged from 0.01 to 0.29 ng·m⁻³. The spiked recoveries of SCCPs, MCCPs, and LCCPs at the low, medium, and high concentrations were 77.38%-81.64%, 93.11%-99.78%, and 87.41%-101.39%, respectively, and the relative standard deviations (RSDs) were 2.90%-12.84%. This method was used to determine the CPs levels in 11 PM_2.5 samples from Shijiazhuang. The positive rates of ∑SCCPs, ∑MCCPs, and ∑LCCPs were all 100%, the concentration ranges were 0.24-2.18 ng·m⁻³ (mean 0.84 ng·m⁻³), 0.17-1.67 ng·m⁻³ (mean 0.70 ng·m⁻³), and 0.01-0.16 ng·m⁻³ (mean 0.04 ng·m⁻³), respectively, and the percentages to ΣCPs were 52.95%, 44.39%, and 2.66%, respectively. Conclusion The method established in this study is simple, time-saving, solvent saving, and can simultaneously detect SCCPs, MCCPs, and LCCPs in PM_2.5, which is suitable for the determination of PM_2.5 samples in large quantities, and can also provide a reference for the detection methods of other halogenated organic compounds in PM_2.5.