Since 1971 Yoneda et al. [13] first application the total reflection technology to XRF, they determined uranium in seawater, iron in the blood, and rare earth elements in hot-spring water. The theoretical basis and experimental conditions were subsequently investigated. In Vienna, Austria, Wobrauschek wrote a Ph.D. thesis on the subject [14], and together with Aiginger, they reported detection limits of nanograms [15] [16]. In Geesthacht near Hamburg, Germany, Knoth, and Schwenke found element traces on the ppb-level [17] [18]. In the decade after 1980, a great variety of applications promoted a growing interest, the number of instruments in use increased to about 200 worldwide.

In 1981, the West German Rich Seifer Company successfully developed the first commercial total reflection X-ray fluorescence spectrometer. Since then, the development and application of the TXRF instrument have been rapidly developed and improved. Since 1984, several TXRF seminars have been held internationally [19]. Since the 1990s, China has been led by the Institute of High Energy Physics [10], the Institute of Modern Physics [20], and the Chinese Academy of Atomic Energy, which have successively carried out the development of TXRF analysis devices and the research and promotion of analysis methods.

In 1983, the angular dependence of the fluorescence intensities in the range below the critical angle of total reflection was first observed by Becker et al. [21] It led to the nondestructive investigation of surface contamination and thin near-surface layers. In 1986, the X-radiation of a synchrotron was first used for excitation by Iida et al. [22]. At a first “workshop” in Geesthacht in 1986, the participants decided to call the new method “total reflection X-ray fluorescence analysis” and introduced the acronym “TXRF”. In 1991, Wobrauschek, Aiginger, Schwenke, and Knoth won the distinguished Bunsen-Kirchhoff Prize of the DASp (Deutsche Arbeitskreis fur Angewandte Spektroskopie) for the development of TXRF. Table 1 shows several important stages of the initial development of the TXRF.

In the years after first reviews and book contributions were published on the subject of TXRF (e.g. [24] [25]). The number of papers about TXRF grew explosively from some 3 to about 125 papers per year with large fluctuations [8]. TXRF is successfully applied all over the world. It is widely used in the analysis and determination of macro, trace elements in various fields such as chemical industry, food, environmental protection, biology, medicine, legal inspection, high-purity materials, geology and minerals, metallurgy, etc. [26]. In 1995, Tian Yuhong et al. [10] researched the structure of the secondary total reflection system. The minimum detection limit of the copper target under small beam conditions can reach 0.6 × 10⁻⁹, and the platinum target can reach 2 × 10⁻⁹. In 1996, when Christina Streli [27] used TXRF to analyze light elements, he compared the effects of possible x-ray sources such as standard x-ray tubes, special windowless x-ray tubes, and synchrotron radiation, and he using special excitation sources and special spectral correction components to reduce the detection limit and reduce the background count. C. Surely, Burba P, et al. have further studied the X-ray source, he found that detection limits depend upon the source. When

using synchrotron radiation as an X-ray source the detection limits are in the range of some hundred femtograms [28] while in the range of some pg when using a special windowless X-ray tube with a-Si anode [29].

TXRF is used everywhere. In terms of environmental protection, the TXRF analysis of environmental samples (such as water, soil, air particles, animals and plants, etc.) [30] - [37] can evaluate environmental changes. Erick K. Towett et al. [32] [33] used TXRF to study the element content in the soil, and compared with the ICP-MS measurement results after digestion, it showed the feasibility of TXRF measurement results in soil. Liu Guangya [34] used TXRF to measure atmospheric particles and evaluate air pollution. Through TXRF research on geological samples (such as ores, crystals, and mineral raw materials), geological and geochemical surveys and mineral census are realized. Cherkashina Ty et al. [38] used TXRF to study ore samples and proved that TXRF can quickly detect ore samples. In the chemical industry, product quality control can be achieved by analyzing the element or impurity content of chemical products (petroleum and petroleum products, fertilizers, wastes, films) [39] [40] [41] [42]. In foreign countries, I. De La Calle et al. [41] used TXRF to measure metal content in smelting slag to assess whether the smelting slag treatment process is appropriate and judge whether the slag can be recycled. F. M. Adebiyi et al. [39] used TXRF to analyze trace elements in Nigerian oil sands. In the field of medicine and food, Lankosz M W et al. [43] used TXRF to measure trace elements in human brain tissue to distinguish the disease level. Li Meng [44] studied the relationship between mineral elements and diseases through TXRF analysis of the hair of chronic hepatitis B patients and healthy people. In China, the use of TXRF is mainly concentrated in food (such as fish, fruits, nuts, pollen, tea) [45] [46] [47] [48] and the medical field, such as Yu Huichun et al. [45] for different types of wine grapes. Wang Shuxun [49] uses TXRF analysis Ganoderma lucid from different origins. Table 2 shows some applications of TXRF in mid-term development.

In the past few years, many instrument improvements have been done, and elemental analysis has been done in the following applied research fields.

1) Minerals: feldspar, antimony oxide, gold ore, fluorite [50] ;

2) Metallurgy: nickel electrolyte, cast iron, bearings;

3) Environmental protection: pure water [51], mineral water, tap water, sewage, atmospheric dust, sludge, high salinity salt lake water; soil [52] ;

4) Chemical industry: catalyst formula for purifying automobile exhaust, sulfur in diesel, ceramic glaze formula;

5) Biology: teeth, marine animals, blood [53], cells and proteins, body fluids;

6) Legal inspection: Appraisal of samples at the crash site [54] ;

7) Material: glass, high purity quartz impurity content; medicine: trace elements in hair [46], nails, harmful trace elements in salvia;

8) Food: beneficial and harmful elements in beverages, rice [55], plant materials, leaf roots, and stems.

In 2017, Mercedes Radio [56] investigated the effect of an inorganic (CaCl₂) and an organic matrix on metals quantification by TXRF for liquid samples. In 2018, Tsugufumi Matsuyama [57] proposed a new methodology to evaluate uranium concentration in water containing many kinds of impurities by total reflection X-ray fluorescence analytical. Hikari Takahara [58] developed a non-dissolution preparation method for powder sample analysis by total reflection X-ray fluoresce spectrometry (TXRF). In 2019, I.Szaloki [12], et al. presented a new fundamental parameter model and calculation algorithm for quantitative analysis for total reflection X-ray fluorescence analytical technique. In 2020, Aleksandra Winkler [59] et al. determined the elemental composition of various herbal infusions and teas, including trace elements by using total reflection X-ray fluorescence (TXRF). Gruber Andreas [60] precisely quantify iron and other trace metals in a variety of biological samples by total reflection X-ray fluorescence (TXRF) analysis. Alex von Bohlen [7] explained that TXRF analysis is not working completely free of matrix effects if the thickness of the residue of matrix samples according to the results of TXRF analysis of the different components of beverages exceeds a certain margin. Table 3 is a number of applications TXRF in recent years.