The Controllable Preparation Of Uniform Bas04 Spheres And Its Application In Hdl Dry Diagnosis

With excellent physicochemical characteristics,eg.,non-toxicity,acid and alkali resistance,high reflectivity,and high whiteness,barium sulfate(BaS04)has been widely used in filling pigments,ceramics,paper,contrast agents,adsorbents,plastics agents and other fields.Besides,the homogeneous particle size BaS04 microspheres have advantages of high light reflectivity,and the accumulated voids can effectively and uniformly disperse the serum and achieve the purpose of filtration separation.Therefore,the BaS04 microspheres can be used as a filtration-diffusion-reflection multi-functional layer for medical dry diagnostic reagents.At present,it is one of the research hotspots and key technologies to prepare the uniform particle size of micron-sized BaS04 in the field of medical dry diagnostics.In this paper,ethylenediamine tetraacetic acid disodium(EDTA·2Na)was used as a complexing agent to control the preparation of micron-sized barium sulfate spheres via a precipitation reaction between sodium sulfate and barium chloride.To better characterize the morphology,structure and particle size of barium sulfate spheres and understand the formation mechanisms,XRD,FTIR,PSD and SEM were employed.The influence of pH value,[EDTA/Ba2+]ratio,[Ba2+]concentration,reaction temperature and reaction time on the size and morphology of barium sulfate were investigated and optimized.Moreover,a primary understanding of the formation mechanism of micron-sized spherical barium sulfate spheres is presented according to the crystallization process.The SEM showed that the prepared BaS04 microspheres can reach a particle size of 3 ?m with excellent uniformity and monodispersity.The yield of BaS04 microspheres was analyzed,and an effective way to increase the yield was given with over 93%of the synthesis yield.The BaS04 filtration-diffusion-reflection multi-functional layers were prepared with the BaSO4 microspheres.The effects of cellulose acetate(CA),slurry mixing time,surfactant(Tween 80)and other factors on the BaS04 multifunctional layer were investigated.Under the optimal conditions,the pores of BaS04 multi-functional layer are distributed evenly and densely,and the BaS04 multi-functional layer is free of cracks,falling powder and other phenomena.It was found that in the range of 400-750 nm the BaSO4 multifunctional layer can reach more than 99%measured using a reflectance spectrometer.In addition,the SEM characterization results show that the BaS04 multi-functional layer prepared from self-made BaS04 microspheres is significantly superior to the BaS04 multi-functional layer prepared from commercially available amorphous BaS04powders.The BaS04 multifunctional layer was applied to a homemade high-density lipoprotein reagent layer to obtain a high-density lipoprotein dry sheet(HDL).The experimental results show that the high-density lipoprotein dry tablets obtained by using the BaS04 multi-functional layer have the advantages of uniform diffusion,good reproducibility to the same concentration of test sample serum,and sensitivity to serum of different concentrations of the test sample.Therefore,the homogeneous particle size BaS04 microspheres prepared by this method can be successfully applied to dry chemistry in vitro diagnostic reagents.