The Analysis Of Tris(2,3-Dibromopropyl) Isocyanurate In Mouse Organs By Mass Spectrometry

Brominated flame retardants(BFRs)are important commercial additives which can protect the commodities from fire.Increasing evidences indicate that traditional BFRs are bioaccumulative and persistent in the environment.Thus,with the phasing out of traditional BFRs,novel brominated flame retardants(NBFRs)have been used widely as substitutions to ensure fireproof performance of commodities.Tris(2,3-dibromopropyl)isocyanurate(TBC)is one of the semi-volatile additive NBFRs.Toxicological studies have proved that TBC shows certain toxicity to fish and rodent.However,to our knowledge,there was no research on bioaccumulation and distribution of TBC in mammals’organs.Hence,the concentrations of TBC in mouse organs were quantitatively analyzed by HPLC-MS/MS,and the spatial distributions of TBC in the mouse organs were in situ analyzed by MALDI-IMS.The details,including three parts,are as follows:1.Establishment of analytical methods for TBC by mass spectrometry:We established an efficient ultrasonic extraction-SPE purification-HPLC-MS/MS for the quantification of TBC in biological tissues.Excellent linearity(R~2>0.995)was found at 5 ng/m L-500 ng/m L concentration range.The recoveries of TBC in spiked samples were between 81.1%-96.4%,and the RSD was less than 15.3%.The method was sensitive,with LOD and LOQ as 0.32 ng/m L and 1.08 ng/m L,respectively.This method has good reproducibility and low matrix interference,which is reliable for further analysis.In order to address the issue that TBC has low ionization efficiency and is hard to detect by MALDI-MS,a novel MALDI-MS method for TBC was established based on the combination of silver trifluoromethanesulfonate(Ag OTf)and commercial matrix.The LOD and LOQ of the TBC related signal[2Ag OTf+Br]~-were 0.16μg/m L and 0.54μg/m L,respectively.And the TBC related signal had satisfactory linearity(R~2>0.995)and repeatability(RSD<6.85%).The established MALDI-MS method has high accuracy,sensitivity and reproducibility.2.Quantification of TBC in mouse organs based on the established HPLC-MS/MS method:To investigate the bioaccumulation of TBC in mammals,ICR mice were used as model organisms.The concentrations of TBC in mouse heart,liver,brain and kidney under oral exposure were quantified by the established HPLC-MS/MS method.The result showed that TBC was accumulated in the mouse organs and TBC bioaccumulation in heart,liver,brain,and kidney were different.The concentration of TBC in the tissue was proportional with exposure concentration and exposure time.High TBC exposure was more likely to cause liver damage,while long-term exposure was more likely to cause kidney damage.This result provides information for the health risk assessment of TBC in mammals.3.In situ analysis of TBC in mouse organs by MALDI-IMS:To investigate the distribution of TBC in mouse organs,ICR mice were used as model organisms,and in situ localization of TBC in mouse organs was determined by MALDI-IMS.As commercial matrixes were not able to detect TBC in tissue section,we used the developed combination matrix for the TBC spatial distribution in the mouse kidney and liver(part).The result showed that TBC was accumulated in kidney and liver.TBC was mainly distributed in the renal parenchyma,not uniformly accumulated in the kidney.In addition,the H&E staining results indicated that TBC exposure can cause glomerular atrophy.The glomerular are mainly located in the renal parenchyma and the high concentration of TBC in the renal parenchyma suggests that glomerular atrophy may be directly caused by TBC.