Moisture Influence Reducing Method for Heavy Metals Detection in Plant Materials Using Laser-Induced Breakdown Spectroscopy: A Case Study for Chromium Content Detection in Rice Leaves

Abstract

Fast detection of heavy metals in plant materials is crucial for environmental remediation and ensuring food safety. However, most plant materials contain high moisture content, the influence of which cannot be simply ignored. Hence, we proposed moisture influence reducing method for fast detection of heavy metals using laser-induced breakdown spectroscopy (LIBS). First, we investigated the effect of moisture content on signal intensity, stability, and plasma parameters (temperature and electron density) and determined the main influential factors (experimental parameters F and the change of analyte concentration) on the variations of signal. For chromium content detection, the rice leaves were performed with a quick drying procedure, and two strategies were further used to reduce the effect of moisture content and shot-to-shot fluctuation. An exponential model based on the intensity of background was used to correct the actual element concentration in analyte. Also, the ratio of signal-to-background for univariable calibration and partial least squared regression (PLSR) for multivariable calibration were used to compensate the prediction deviations. The PLSR calibration model obtained the best result, with the correlation coefficient of 0.9669 and root-mean-square error of 4.75 mg/kg in the prediction set. The preliminary results indicated that the proposed method allowed for the detection of heavy metals in plant materials using LIBS, and it could be possibly used for element mapping in future work.

Rapid Determination of Cadmium Contamination in Lettuce Using Laser-Induced Breakdown Spectroscopy

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Rapid Identification of Kudzu Powder of Different Origins Using Laser-Induced Breakdown Spectroscopy

“…Laser-induced breakdown spectroscopy (LIBS) is an atomic emission spectroscopy technique that has emerged in recent years [21,22,23]. A high energy pulsed laser is used to heat and ablate the sample [24].…”

Quantitative Analysis of Nutrient Elements in Soil Using Single and Double-Pulse Laser-Induced Breakdown Spectroscopy

“…Laser-induced breakdown spectroscopy (LIBS) is a recently developed spectral detection technique [ 6 ]. Because of the advantages of fast analytical speed, simple sample pretreatment, multi-element simultaneous detection capability, as well as the potential of in situ or stand-off analysis [ 7 ], it has been widely used for the elemental analysis of various kinds of samples, including plants [ 8 ], water [ 9 ], and especially soils. Martin et al applied LIBS to determine the carbon and nitrogen content of various soils, and the good results proved that LIBS technique had the potential to be packaged into a field-deployable instrument for real-time and in situ analysis of soil carbon and nitrogen [ 10 ].…”