Accurate and sensitive determination of hydroxychloroquine sulfate used on COVID-19 patients in human urine,serum and saliva samples by GC-MS

A rapid,accurate,and sensitive analytical method,ultrasonication-assisted spraying based fine droplet formationeliquid phase microextractionegas chromatographyemass spectrometry(UA-SFDF-LPME-GCMS),was proposed for the determination of trace amounts of hydroxychloroquine sulfate in human serum,urine,and saliva samples.To determine the best extraction strategy,several liquid and solid phase extraction methods were investigated for their efficiencies in isolation and preconcentration of hydroxychloroquine sulfate from biological matrices.The UA-SFDF-LPME method was determined to be the best extraction method as it was operationally simple and provided accurate results.Variables such as the extraction solvent,spraying number,sodium hydroxide concentration and volume,sample volume,mixing method,and mixing period were optimized for the proposed method using the onevariable-at-a-time approach.In addition,Tukey’s method based on a post hoc comparison test was employed to evaluate the significant difference between the parameters inspected.After the optimization studies,the limit of detection(LOD)and limit of quantification(LOQ)were determined to be 0.7 and 2.4 mg/kg,respectively.The sensitivity of the GC-MS system based on the LOD was enhanced approximately 440-fold when the UA-SFDF-LPME method was employed.Spiking experiments were also conducted for the human serum,urine,and saliva samples to determine the applicability and accuracy of the proposed method.Recoveries for the human serum,urine,and saliva samples were found to be in the ranges of 93.9%-101.7%,95.2%-105.0%,and 93.1%-102.3%,respectively.These results were satisfactory and indicated that the hydroxychloroquine sulfate level in the above biological samples could be analyzed using the proposed method.

Synthesis of a Novel Imidazole Ionic Liquid Modified Mesoporous Silica SBA15 for Selective Separation and Determination of Inorganic Arsenic in Rice

A novel 1-methylimidazole ionic liquid modified SBA15 mesoporous silica(1-MIIL@SBA15) was synthesized and applied to selective separation of inorganic arsenic(iAs) in rice by dispersive solid phase extraction(DSPE), followed by hydride generation-atomic fluorescence spectrometric(HG-AFS) quantification. The prepared sorbent was characterized by FTIR, FESEM, BET and Zeta potential. Key parameters of adsorption and desorption in DSPE were optimized using standard reference material 1568 b rice flour. Under optimal conditions, the limit of detection was 8.776 ng/kg, relative standard deviation was ≤2.0%, and recoveries of iAs were in the 92.3～94.4% range. This method was successfully applied to the determination of iAs in rice. Under acidic condition, the electrostatic interaction between the positively charged 1-MIIL@SBA15 and anionic iAs played an important role in selective iAs separation, rendering this method suitable for iAs analysis.