Fast and High Sensitive Analysis of Lead in Human Blood by Direct Sampling Hydride Generation Coupled with in situ Dielectric Barrier Discharge Trap.

A direct sampling hydride generation (HG) system based on modified gas liquid separator (GLS) coupled with in situ dielectric barrier discharge (DBD) is first rendered to detect lead in blood samples. Herein, a triple-layer coaxial quartz tube was employed as DBD trap (DBDT) to replace the original atomizer of atomic fluorescence spectrometry (AFS) to satisfy the in situ preconcentration. After 40-fold dilution, foams generated from protein in a blood sample can be eliminated via the double-GLS set; and lead in a blood sample were generated as plumbane under 3.5% HNO3 (v:v) and 30 g/L NaOH with 8 g/L KBH4, 10 g/L H3BO3, and 5 g/L K3[Fe(CN)6]. Then, lead analyte was trapped on the DBD quartz surface by 9 kV discharging at 50 mL/min air; and subsequently released by 12 kV discharging at 110 mL/min H2. The absolute detection limit (LOD) for Pb was 8 pg (injection volume = 2 mL), and the linearity (R2 > 0.997) range was 0.05 - 50 µg/L. The results were in good agreement with that of blood certified reference materials (CRM), and spiked recoveries for real blood samples were 95 - 104% within a relative standard deviation of 5% (RSD). Via gas phase enrichment, the established method improved analytical sensitivity (peak height) by 8 times. The entire analysis time including blood sample preparation can be kept to within 10 min. The combination of modified GLS and DBDT can facilitate the quickness, accuracy, and sensitivity, revealing a promising future for monitoring lead in blood to protect humans, especially children's health.