[Size exclusionchromatography-high-performance liquid chromatography-inductively coupled plasma mass spectrometry for measuring the stability of cadmium telluridequantum dots]

Abstract

Objective: To investigate the peak time and peak area of elements in cadmium telluride quantum dots (CdTe QDs) using size exclusion chromatography-high-performance liquid chromatography-inductively coupled plasma mass spectrometry, as well as the biological stability of CdTe QDs in vivo and in vitro. Methods: Transmission electron microscope and ultraviolet fluorescence were used for characterization and synthesis of water-soluble CdTe QDs, and CdTe QDs were added to double-distilled water, mobile phase, or bovine serum medium to observe the change in stability after different periods of time. CdTe QDs were injected into the vein of mice, and the changes in the morphology of CdTe QDs in serum and the liver were measured at 1, 24, and 72 hours after exposure. Size exclusion chromatography-high-performance liquid chromatography was used for the elution of the compounds in the solution based on their volume, and then inductively coupled plasma mass spectrometry was performed for the eluent. The flow time of (114)Cd and (130)Te and molar ratio were used for qualitative analysis of CdTe QDs, and the peak area was used to judge whether CdTe QDs were degraded. Results: CdTe QDs were diluted to a concentration of 0.5 mmol/L with double-distilled water and then placed in a dark place at room temperature; CdTe QDs were completely degraded after 60 minutes. CdTe QDs were diluted to a concentration of 0.005 mmol/L with a mobile phase, and the peak of CdTe QDs was not detected. After CdTe QDs were placed in a dark place at room temperature for 48 hours at a concentration of 0.005 mmol/L in bovine serum mediumin vitro, the peak area of (114)Cd was 6179841-7346084, and the peak area of (130)Te was 1077913-1191066. CdTe QDs had the highest peak area at 1 hour after exposure, and the peak areas of (114)Cd and (130)Te were 18183894 and 25187987, respectively. CdTe QDs were quickly degraded in the liver; at 1 hour after exposure, the degradation products of CdTe QDs containing Cd were observed in liver tissue homogenate, and CdTe QDs were largely degradedat 24 hours. Conclusion: This method can be used to investigate the biological stability of CdTe QDs. CdTe QDs are degraded in the liver and produce Cd(2+), which may cause toxic reaction.

Keywords: Cadmium; Chromatography, high pressure liquid; Inductively coupled plasma mass spectrometry; Quantum dots.