A Portable
Microplasma Optical Emission Spectrometric
Device with Online Digestion Function for Field and Sensitive Determination
of Lead in Biological Samples
posted on 2024-02-19, 20:03authored byJi-Ying Cai, Xiao Zhang, Yu-Jia Wei, Shuai Chen, Yong-Liang Yu, Jian-Hua Wang
Accurate detection and screening of Pb in biological
samples is
helpful to assess the risk associated with lead pollution to human
health. However, conventional atomic spectroscopic instruments are
bulky and cumbersome, requiring additional sample pretreatment equipment,
and difficult to perform field analysis with. Herein, a portable point
discharge (PD) microplasma-optical emission spectrometric (OES) device
with online digestion function is designed for field and sensitive
determination of lead in biological samples. With rice as a model,
online digestion of a batch of six 50 mg samples can be achieved in
the HNO3 and H2O2 system within 25
min by a temperature control and timing module. Compared to the conventional
microwave digestion, the digestion efficiency of this device reaches
97%. Pb in digestion solution is converted into volatile species by
hydride generation (HG) and directly introduced into PD-OES for excitation
and detection by a self-designed rotatable and telescopic cutoff gas
sampling column. Six samples can be successively detected in 2 min,
and argon consumption of the whole process is only <800 mL. Under
the optimized conditions, the detection limit of Pb is 0.018 mg kg–1 (0.9 μg L–1) and precision
is 3.6%. The accuracy and practicability of the present device are
verified by measuring several certified reference materials and real
biological samples. By virtue of small size (23.5 × 17 ×
8.5 cm3), lightweight (2.5 kg), and low energy consumption
(24.3 W), the present device provides a convenient tool for field
analysis of toxic elements in biological samples.