# Application of Corrected Methods for High-Resolution XRF Core Scanning Elements in Lake Sediments
## 1 Introduction  
The X-ray fluorescence (XRF) core scanner (hereafter \"XRF-scan\") provides a rapid, cost-effective and non-destructive means of obtaining high-resolution elemental measurements and has been widely used in climatic and environment studies [1; 2; 3; 4; 5; 6]. However, the elemental intensities determined from wet sediments using the XRF core scanner are heavily influenced by the sediment properties (i.e., grain size, water content and surface elevation) of the core [7; 8; 9; 10; 11; 12; 13; 14], particularly for high-resolution scans [10]. In such cases, the XRF-scan results are typically presented as intensities of detected elements, usually in counts or counts per second, rather than quantitative results [10]. Comparisons between the XRF-scan with conventional destructive techniques for determining element geochemistry (e.g., ICP-MS, ICP-OES, EDP-XRF and WD-XRF) in which the influences of sediment inhomogeneities were removed, could yield quantitative element weighted-proportions or mass fractions (in percentage or mg/kg; hereafter referenced as \"conventional-fractions\") [7; 10; 11; 15; 16].  
However, conventional approaches are time-consuming, low resolution and require a large amount of sample material [7; 11]. Various studies have attempted to transform XRF-scan data to conventional element fraction data using a range of methods, with linear regression being the most common [1; 8; 9; 17]. [PERSON] and [PERSON] [10] applied various non-linear functions to transform XRF-scan intensities into fractions. Other studies have employed element ratios to reduce analytical uncertainties caused by inhomogeneous sediment properties [3; 12; 18; 19; 20]. Unfortunately, these ratios are insufficient to enable rigorous statistical analysis of compositional data [10].  
Several normalized calibration methods and log-ratio calibration models which convert XRF-scan intensities to conventional element fractions have been developed, such as the normalized median-scaled (NMS) calibration [9], the normalized polynomial-scaled (NPS) calibration [7], the log-ratio calibration equation (LRCE) [10] and the multivariate log-ratio calibration (MLC) model [21]. The performance of specific calibrations has been investigated in some detail, for instance [PERSON] et al. [21] evaluated the log-ratio methods LRCE and MLC, whilst [PERSON] et al. [7] compared the NMS, NPS and MLC methods. Furthermore, [PERSON] et al. [16] compared the linear calibration, LRCE and MLC methods. However, to our knowledge, there is no comprehensive evaluation of each of these XRF-scan calibrations. In addition, the impact of sediment properties on XRF-scan intensities remains unclear.  
In the present study, we evaluated the NMS [9], NPS [7], LRCE [10] and MLC [21] calibration methods by utilizing high-resolution XRF-scan results from a lake sediment core (FXH-B2). This was achieved via: 1) comparing the calibrated XRF-scan intensities with their known elemental fractions; and 2) quantitative evaluation of the calibration performance using the mean squared relative error (MSRE) of elements. The most suitable calibration method was then applied to a separate 18.12 m-long sediment core (LGH2) to assess the extent to which specific sediment properties (i.e., grain size and water content), affected the XRF-scan results.