This study established a method using gas chromatography-electrostatic field Orbitrap high-resolution mass spectrometry(Orbitrap GC-MS)for the simultaneous determination of 70 organic pollutants across 4 categories:or...This study established a method using gas chromatography-electrostatic field Orbitrap high-resolution mass spectrometry(Orbitrap GC-MS)for the simultaneous determination of 70 organic pollutants across 4 categories:organochlorine pesticides(OCPs),polycyclic aromatic hydrocarbons(PAHs),polychlorinated biphenyls(PCBs),and phthalates(PAEs)in infant cereal-based supplementary foods.Techniques integrating cryogenic centrifugation and lipid and protein adsorbent(LPAS)purification were employed.The precise mass numbers of target compounds were determined by Orbitrap GC-MS in full-scan mode(Full MS),which effectively minimized matrix interferences in these foods.Method validation on rice flour samples demonstrated that the 70 compounds exhibited excellent linearity within their respective mass concentration ranges,with correlation coefficients all exceeding 0.995.The detection limits for this method ranged 0.10–1.00μg/kg,while the quantification limits varied 0.3–3.0μg/kg,meeting the established detection requirements.The average spike recovery of the 70 compounds at 3 spiked levels(5,20,and 100μg/kg)ranged 75.3%–119.3%,with relative standard deviations ranging 1.8%–10.8%.Both inter-day and intra-day precision demonstrated relative standard deviation values below 15%.This method was applied to analyze 100 samples of commercial infant cereal-based supplementary food,revealing the presence of PAEs and PAHs in 12.0%of the samples.Notably,no OCPs or PCBs were detected.The detected concentrations of benzo[a]pyrene(Ba P)and dibutyl phthalate(DBP)were(4.2±0.1)and(1.8±0.3)μg/kg,respectively.This method is straightforward,highly sensitive,and suitable for the rapid screening and confirmation of 70 organic pollutants in infant cereal-based supplementary foods.展开更多
Corrosion at the taper/trunnion interface of total hip replacement(THR)often results in severe complications.However,the underlying mechanisms of biotribocorrosion at the taper/trunnion interface during the long-term ...Corrosion at the taper/trunnion interface of total hip replacement(THR)often results in severe complications.However,the underlying mechanisms of biotribocorrosion at the taper/trunnion interface during the long-term walking gait cycles remain to be fully understood.In this study,a hip joint simulator was therefore instrumented with an electrochemical cell for in-situ monitoring of the tribocorrosion evolution in a metal-on-polyethylene(MoP)THR during a typical long-term walking gait.In addition,the biotribocorrosion mechanism was investigated via surface and chemical characterizations.The experimental results confirmed that the taper/trunnion interface dominated the contemporary MoP hip joint corrosion.Three cyclic variations in the open circuit potential(OCP)were observed throughout the long-term electrochemical measurements,attributed to the formation and disruption of the adsorbed protein layer.The corrosion exhibited an initial increase at each period,peaking at approximately 0.125 million cycles,followed by a subsequent gradual reduction.Surface and chemical analyses revealed the formation of a tribochemical reaction layer(tribolayer)on the worn surface of the taper/trunnion interface.The surface/chemical characterizations and the electrochemical measurements indicated that the adhesion force of the adsorbed protein layer was weaker than that of the tribolayer.In contrast,the opposite was true for the corrosion resistance.Based on the observations from this study,the tribocorrosion mechanism of the taper/trunnion interface under the long-term walking gait cycles is deduced.展开更多
The adsorption of plasma proteins onto biomaterials can be characterized by either the amount of adsorbed protein or the conformation of the adsorbed proteins. The adsorption characteristics of biomaterials are import...The adsorption of plasma proteins onto biomaterials can be characterized by either the amount of adsorbed protein or the conformation of the adsorbed proteins. The adsorption characteristics of biomaterials are important for hemocompatibility evaluation. In this investigation, the amount of adsorbed human fibrinogen (HFG) and the conformation of the adsorbed HFG on different surfaces were measured simultaneously using transmission FTIR. The surface materials included CaF 2, polymethyl methacrylate (PMMA), type II polyurethane made by Chengdu University of Science & Technology, pellethane 2363 55D and pellethane 2363 80A. The results indicate that both the amount of adsorbed protein and the conformation of the adsorbed protein can be measured simultaneously using a single transmission FTIR technique. The result also suggests that a single parameter, either the adsorbed amount or the conformation of the adsorbed HFG, can not provide complete information about the hemocompatibility of the biomaterials.展开更多
基金funded by National Key Research and Development Program for Young Scientists of China(2022YFF1102900)Hebei Province High-level Talent Funding Project(C20221009)。
文摘This study established a method using gas chromatography-electrostatic field Orbitrap high-resolution mass spectrometry(Orbitrap GC-MS)for the simultaneous determination of 70 organic pollutants across 4 categories:organochlorine pesticides(OCPs),polycyclic aromatic hydrocarbons(PAHs),polychlorinated biphenyls(PCBs),and phthalates(PAEs)in infant cereal-based supplementary foods.Techniques integrating cryogenic centrifugation and lipid and protein adsorbent(LPAS)purification were employed.The precise mass numbers of target compounds were determined by Orbitrap GC-MS in full-scan mode(Full MS),which effectively minimized matrix interferences in these foods.Method validation on rice flour samples demonstrated that the 70 compounds exhibited excellent linearity within their respective mass concentration ranges,with correlation coefficients all exceeding 0.995.The detection limits for this method ranged 0.10–1.00μg/kg,while the quantification limits varied 0.3–3.0μg/kg,meeting the established detection requirements.The average spike recovery of the 70 compounds at 3 spiked levels(5,20,and 100μg/kg)ranged 75.3%–119.3%,with relative standard deviations ranging 1.8%–10.8%.Both inter-day and intra-day precision demonstrated relative standard deviation values below 15%.This method was applied to analyze 100 samples of commercial infant cereal-based supplementary food,revealing the presence of PAEs and PAHs in 12.0%of the samples.Notably,no OCPs or PCBs were detected.The detected concentrations of benzo[a]pyrene(Ba P)and dibutyl phthalate(DBP)were(4.2±0.1)and(1.8±0.3)μg/kg,respectively.This method is straightforward,highly sensitive,and suitable for the rapid screening and confirmation of 70 organic pollutants in infant cereal-based supplementary foods.
基金supported by the National Natural Science Foundation of China(52035012)the Science and Technology Planning Project of Sichuan Province(2020YJ0032)the 111 Project(B20008).
文摘Corrosion at the taper/trunnion interface of total hip replacement(THR)often results in severe complications.However,the underlying mechanisms of biotribocorrosion at the taper/trunnion interface during the long-term walking gait cycles remain to be fully understood.In this study,a hip joint simulator was therefore instrumented with an electrochemical cell for in-situ monitoring of the tribocorrosion evolution in a metal-on-polyethylene(MoP)THR during a typical long-term walking gait.In addition,the biotribocorrosion mechanism was investigated via surface and chemical characterizations.The experimental results confirmed that the taper/trunnion interface dominated the contemporary MoP hip joint corrosion.Three cyclic variations in the open circuit potential(OCP)were observed throughout the long-term electrochemical measurements,attributed to the formation and disruption of the adsorbed protein layer.The corrosion exhibited an initial increase at each period,peaking at approximately 0.125 million cycles,followed by a subsequent gradual reduction.Surface and chemical analyses revealed the formation of a tribochemical reaction layer(tribolayer)on the worn surface of the taper/trunnion interface.The surface/chemical characterizations and the electrochemical measurements indicated that the adhesion force of the adsorbed protein layer was weaker than that of the tribolayer.In contrast,the opposite was true for the corrosion resistance.Based on the observations from this study,the tribocorrosion mechanism of the taper/trunnion interface under the long-term walking gait cycles is deduced.
文摘The adsorption of plasma proteins onto biomaterials can be characterized by either the amount of adsorbed protein or the conformation of the adsorbed proteins. The adsorption characteristics of biomaterials are important for hemocompatibility evaluation. In this investigation, the amount of adsorbed human fibrinogen (HFG) and the conformation of the adsorbed HFG on different surfaces were measured simultaneously using transmission FTIR. The surface materials included CaF 2, polymethyl methacrylate (PMMA), type II polyurethane made by Chengdu University of Science & Technology, pellethane 2363 55D and pellethane 2363 80A. The results indicate that both the amount of adsorbed protein and the conformation of the adsorbed protein can be measured simultaneously using a single transmission FTIR technique. The result also suggests that a single parameter, either the adsorbed amount or the conformation of the adsorbed HFG, can not provide complete information about the hemocompatibility of the biomaterials.
