A method for determining the content of gold and other elements in gold alloy products

Abstract

The present invention relates to the technical field of element content detection, and in particular to a method for determining the gold content and other element contents in a gold alloy product. The method comprises the following steps: 1) dissolving a sample, adding hydrochloric acid, disodium ethylenediaminetetraacetic acid, tartaric acid, oxalic acid, and perchloric acid to prepare a stable sample solution; 2) preparing a calibration solution composed of the main element contents; 3) measuring calibration samples of gold, silver, copper, zinc, nickel, iron, manganese, and chromium with known concentrations to determine the test conditions for the above elements; and 4) testing the calibration solution samples to construct a calibration working curve showing the relationship between X-ray fluorescence spectrum intensity and the gold, silver, copper, zinc, nickel, iron, manganese, and chromium content. The calibration curve is then used to test the sample to determine the gold, silver, copper, zinc, nickel, iron, manganese, and chromium contents in the gold alloy product to be tested. This method can quickly and accurately determine the gold, silver, copper, zinc, nickel, iron, manganese, and chromium contents in gold alloy products with a gold content of 0.15% to 99.9%.

Description

Technical Field

[0001] The present invention relates to the technical field of detecting the elemental composition content of gold alloy products, and specifically to methods for determining the elemental composition content of different types of gold alloy products, including rose gold, K yellow, gold foil, and other gold alloy products, and in particular to methods for accurately determining the elemental composition content of different types of gold alloy products using X-ray fluorescence spectroscopy. Background Art

[0002] Gold alloy products have a wide range of elemental composition, a wide variety of product types, and come in a variety of colors. They are also hard and resistant to deformation, making them popular among consumers. However, compared to pure gold products, these products have a more complex matrix. Traditional methods for determining the gold content of gold products include fire assay and inductively coupled plasma optical emission spectrometry. Fire assay requires high-temperature melting of the sample, the use of large amounts of standard silver, and the removal of the silver with large amounts of acid. Inductively coupled plasma optical emission spectrometry, used for determining the gold content of gold alloy products, typically uses a subtraction method, where the gold content is determined by subtracting the impurity element content. However, this method is suitable for detecting trace element content, but its accuracy is poor for high levels of impurity elements, and even worse for impurity elements exceeding 5%. This results in poor accuracy in calculating the gold content using the subtraction method, and the measurement cost is relatively high. Therefore, it is urgent to establish an efficient and accurate method for determining the gold content and other element contents in gold alloy products to improve detection efficiency and measurement accuracy. The development of this method provides a basis for the determination of the gold content and other element contents in personalized gold alloy products, better protects the property safety of consumers, provides a testing basis and technical support for government supervision, and promotes the healthy development of the precious metal jewelry industry.

[0003] Currently, X-ray fluorescence spectroscopy (XRF) is used to determine the gold content of gold alloy jewelry. This technology primarily uses solid samples for direct testing, and the gold content of the product is screened based on the test results. This approach is not capable of accurate measurement. This is primarily due to the fact that gold alloy products are heavy matrix products, and X-ray fluorescence spectroscopy testing of gold and other elemental content results in significant matrix interference. Furthermore, gold alloy products with different elemental compositions exhibit varying interference, necessitating calibration using a similar matrix standard sample to obtain accurate measurement results. However, accurate gold content determination using matrix-matched standard samples still requires substantial foundational work, such as the development of reference materials, particularly those with a wider range of impurity types and content.

[0004] Therefore, the present invention has carried out a lot of innovative research work to address the technical difficulties faced in the above-mentioned actual detection process, and has achieved accurate and rapid determination of the gold content and other element contents of gold alloy products. It has also explored the sample dissolution and coexistence technology of products with high impurity element content, and developed a detection method for determining the gold content and other element contents of gold alloy products using X-ray fluorescence spectroscopy technology suitable for different types of products. A new detection scheme for accurately and rapidly determining the gold content and other element contents of gold alloy products is proposed. Summary of the Invention

[0005] The present invention aims to provide a method for determining the gold content and other element contents in gold alloy products. The present invention proposes using X-ray fluorescence spectroscopy to accurately and rapidly determine the gold content and other element contents in gold alloy products. First, the sample to be tested is dissolved, and a high-content coexistence system of constituent elements is established for samples with different elemental compositions. A calibration solution is then prepared, and X-ray fluorescence spectroscopy is used to rapidly and accurately determine the gold content and other element contents. The present invention can rapidly and accurately determine the gold content and impurity element content in gold and gold jewelry, providing a method suitable for rapidly and accurately determining the gold content and other element contents in gold alloy products with a wide content range and complex elemental composition. The detection process is convenient and rapid, and the test results are accurate and consistent.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A method for determining the gold content and other element contents in a gold alloy product comprises the following steps:

[0008] (1) Weigh a certain mass of gold alloy sample, dissolve the sample in a mixed acid solution of hydrochloric acid and nitric acid, add appropriate amounts of hydrochloric acid, disodium EDTA, oxalic acid, tartaric acid, and perchloric acid to prepare a stable sample solution, and adjust the volume with hydrochloric acid and water (volume ratio not less than 1:1);

[0009] (2) According to the gold content and other element content ranges of different types of gold alloy products, weigh appropriate amounts of pure metal samples of gold, silver, copper, zinc, nickel, iron, manganese, and chromium with a purity greater than 99.99% and place them in a beaker;

[0010] Among them, gold, copper, zinc, nickel, iron, and manganese are dissolved in a mixed acid solution of hydrochloric acid and nitric acid; silver is dissolved in a nitric acid solution at room temperature, and then a hydrochloric acid solution is slowly added, and heated to a slight boil to prepare a clear solution; chromium is added to the hydrochloric acid solution and heated to dissolve; the above-dissolved samples are mixed, and appropriate amounts of hydrochloric acid, disodium ethylenediaminetetraacetic acid, oxalic acid, tartaric acid, and perchloric acid are added to adjust to ensure the stability of the test solution under the coexistence of gold, silver, copper, zinc, nickel, iron, manganese, and chromium, and the volume is constant to obtain a standard stock solution; an appropriate amount of the standard stock solution is measured to prepare a series of standard solutions for constructing a calibration working curve. The series of standard solutions are prepared for constructing a standard working curve;

[0011] (3) Using an X-ray fluorescence spectrometer to measure a series of standard solutions with known gold, silver, copper, zinc, nickel, iron, manganese, and chromium contents, construct standard working curves of the relationship between X-ray fluorescence spectrum intensity and gold, silver, copper, zinc, nickel, iron, manganese, and chromium content, and determine the test conditions for gold, silver, copper, zinc, nickel, iron, manganese, and chromium standard sample elements;

[0012] (4) According to the gold alloy product dissolution conditions and the test conditions of gold, silver, copper, zinc, nickel, iron, manganese, and chromium elements determined in steps (1) to (3), the target element content of the gold alloy product test solution to be tested is determined by using an X-ray fluorescence spectrometer. According to the relationship between the X-ray fluorescence spectrum intensity and the gold, silver, copper, zinc, nickel, iron, manganese, and chromium element content in the standard working curve constructed in step (3), the content of gold, silver, copper, zinc, nickel, iron, manganese, and chromium elements in the gold alloy jewelry to be tested is calculated using the formula. The target object content calculation formula is:

[0013]

[0014] In formula (1):

[0015] W i %: represents the mass percentage of the target element i;

[0016] V: represents the constant volume of the sample solution to be tested, in mL;

[0017] m: represents the weight of the sample to be tested, in g;

[0018] C i : Indicates the concentration of the target element read by the instrument test, in g / mL;

[0019] C0: Indicates the concentration of the target element in the blank test solution read by the instrument test, in g / mL.

[0020] Preferably, in step (1), for every 0.2 g to 2.0 g of the gold alloy product, 10 mL to 20 mL of a mixed acid solution of hydrochloric acid and nitric acid (volume ratio not less than 5:1) is used to dissolve the sample at 80° C. to 120° C., and 1 mL to 50 mL of hydrochloric acid, 1 g to 8 g of disodium edetate, 1 g to 6 g of oxalic acid, 1 g to 4 g of tartaric acid, and 1 mL to 3 mL of perchloric acid are added to prepare a stable sample solution.

[0021] Furthermore, step (1) is specifically as follows: 0.3 g of the gold alloy product is placed in a beaker, 10 mL of mixed acid (hydrochloric acid and nitric acid in a volume ratio of 5:1) is added, and the mixture is heated to dissolve at 90° C., and after the sample solid is completely dissolved, the temperature is lowered to about 50° C., 40 mL of analytical pure hydrochloric acid solution is added, 2 g of disodium ethylenediaminetetraacetic acid, 2 g of oxalic acid, 1 g of tartaric acid and 1 mL of perchloric acid are added, and the volume is fixed to 100 mL with hydrochloric acid solution (hydrochloric acid and water in a volume ratio of 1:1) to prepare a stable sample solution; a blank solution is prepared according to the same steps.

[0022] Preferably, the gold content and other element content ranges in the different types of gold alloy products described in step (2) are based on a pure metal sample with a purity greater than 99.99%, wherein: 0.8-1.2g gold, 0.22-0.26g silver, 0.50-0.80g copper, 0.10-0.13g zinc, 0.11-0.14g nickel, 0.12-0.16g iron, 0.10-0.12g chromium, and 0.10-0.12g manganese;

[0023] For gold, copper, zinc, nickel, iron, and manganese, add 10 mL of a mixed acid solution of hydrochloric acid and nitric acid, where the volume ratio of hydrochloric acid to nitric acid is 5:1; heat and dissolve at 90°C, and cool to about 50°C until the sample solid is completely dissolved;

[0024] Silver was dissolved in 2 mL of nitric acid at room temperature, and then analytical grade hydrochloric acid was slowly added. The solution was heated to a slight boil to prepare a clear solution, and then cooled to 50°C at room temperature. Chromium was placed in a beaker, and hydrochloric acid was added. The sample was heated at 60°C to dissolve.

[0025] The dissolved sample was mixed and evenly dispersed by ultrasonic vibration. 50 mL of analytical grade hydrochloric acid solution was added, followed by 2 g of disodium ethylenediaminetetraacetic acid, 2 g of oxalic acid, 1 g of tartaric acid, and 1 mL of perchloric acid. The volume was adjusted to 250 mL with hydrochloric acid solution (hydrochloric acid:water volume ratio of 1:1) to obtain a stable standard stock solution. A calibration blank solution was prepared according to the same steps.

[0026] Use a pipette to transfer an appropriate amount of standard stock solution to prepare a series of standard solutions. The specific steps are as follows: use a pipette to accurately transfer 10.00mL, 5.00mL, 2.00mL, 1.00mL, 0.50mL, and 0.20mL, respectively, and dilute to 50mL with hydrochloric acid solution (the volume ratio of hydrochloric acid to water is 1:1, and the solution contains 2% by mass of disodium ethylenediaminetetraacetic acid, 2% oxalic acid, 1% tartaric acid, and 1% by volume of perchloric acid); prepare the calibration blank solution in the same way.

[0027] Preferably, the test conditions for the gold, silver, copper, zinc, nickel, iron, manganese and chromium elements in step (3) are:

[0028] The test conditions for gold are: characteristic spectrum line Lα 9.711 KeV, test time 90 s, X-ray excitation tube voltage 42 kV, X-ray excitation tube current 380 μA, collimation diameter: 8 mm;

[0029] The test conditions for silver are: characteristic spectrum line Kα 22.104 KeV, test time 90 s, X-ray excitation tube voltage 45 kV, X-ray excitation tube current 400 μA, collimation diameter: 8 mm;

[0030] The test conditions for copper are: characteristic spectrum line Kα 8.041 KeV, test time 90 s, X-ray excitation tube voltage 40 kV, X-ray excitation tube current 350 μA, collimation diameter: 8 mm;

[0031] The test conditions for zinc are: characteristic spectrum line Kα 8.631 KeV, test time 90 s, X-ray excitation tube voltage 40 kV, X-ray excitation tube current 350 μA, collimation diameter: 8 mm;

[0032] The test conditions for nickel are: characteristic spectrum line Kα 7.742 KeV, test time 90 s, X-ray excitation tube voltage 38 kV, X-ray excitation tube current 380 μA, collimation diameter: 8 mm;

[0033] The test conditions for iron are: characteristic spectrum line Kα 6.400 KeV, test time 90 s, X-ray excitation tube voltage 38 kV, X-ray excitation tube current 380 μA, collimation diameter: 8 mm;

[0034] The test conditions for manganese are: characteristic spectrum line Kα 5.895 KeV, test time 90 s, X-ray excitation tube voltage 38 kV, X-ray excitation tube current 380 μA, collimation diameter: 8 mm;

[0035] The test conditions for chromium are: characteristic spectrum line Kα 5.411 KeV, test time 90 s, X-ray excitation tube voltage 38 kV, X-ray excitation tube current 380 μA, collimation diameter: 8 mm;

[0036] The full-area peak-to-background ratio background range selected for the 8 element tests is: 15KeV to 21KeV for gold, copper, and iron; 16KeV to 20KeV for zinc, nickel, manganese, and chromium; and 26KeV to 36KeV for silver.

[0037] Preferably, during the measurement process, the thickness of the sample liquid is 5 to 20 mm, and the liquid interface film is a polyethylene material with a thickness of 8 μm.

[0038] Compared with the prior art, the present invention has the following beneficial effects:

[0039] 1) The present invention establishes key steps for determining the gold content and other element contents in gold alloy products by X-ray fluorescence spectrometry, including sample dissolution, coexistence of multi-element ions, calibration solutions and calibration curves with a wide range of target element contents, and matrix interference elimination technology, forming a method for rapid and accurate detection of the gold content and other element contents in gold alloy products; and each step has a certain correlation between them, which has a certain impact on the final detection amount and accuracy of each element.

[0040] 2) In the process of dissolving the gold alloy product, the method of the present invention uses a mixed reagent composed of nitric acid and hydrochloric acid to dissolve the sample, and prepares a stable sample solution by adding disodium ethylenediaminetetraacetic acid, oxalic acid, tartaric acid, and perchloric acid to achieve rapid and accurate determination of the above elements.

[0041] 3) The present invention establishes a sample dissolution and multi-element ion coexistence system for gold alloy products of different types and with a wide range of element contents, and adopts coordination chemical reagents to improve the solubility of metal ions under coexistence conditions, thereby achieving rapid and accurate determination of the contents of eight elements in gold alloy products. The measurement range of gold is: 0.15-99.00wt%, the measurement range of silver is: 0.10-26.00wt%, the measurement range of copper is: 0.10-60.00wt%, the measurement range of zinc is: 0.10-11.00wt%, the measurement range of nickel is: 0.10-12.00wt%, the measurement range of iron is: 0.10-15.00wt%, the measurement range of manganese is: 0.10-10.00wt%, and the measurement range of chromium is: 0.12-10.00wt%, thereby improving detection efficiency.

[0042] 4) The present invention solves the difficulties faced in direct testing of gold alloy products, such as heavy matrix interference, element absorption enhancement effect, and sample heterogeneity, by converting the heavy matrix effect problem existing in direct testing of solid gold alloy samples into a light matrix of a water system. The method of the present invention has been significantly improved in both measurement accuracy and precision.

[0043] 5) The method of the present invention uses X-ray fluorescence spectroscopy to quickly and accurately determine the gold content and other element contents in gold alloy products. The operation process is simple and it is a new type of rapid detection technology. This method creatively transfers the elements of the gold alloy products into an aqueous solution, solving the long-standing problems faced by X-ray fluorescence spectroscopy in testing the chemical composition of substances, such as serious matrix effects, element absorption enhancement effects, sample inhomogeneity and other problems, and the accuracy and precision of the test results are significantly improved. Most importantly, the traditional method of using this type of technology to determine the gold content of gold alloy products is mainly used for compliance screening (such as GB / T 18043-2013), and cannot accurately determine the element content of such samples. The main reason is that the test results are difficult to trace, and the types of related products are complex and diverse, and there is a lack of various types of matching standard substances for accurate measurement. By directly dissolving the sample using pure metal, this method enables traceability of test results, ensuring accuracy. Furthermore, compared to preparing alloy standard samples with varying compositions, preparing standard solutions with varying elemental compositions is much easier. This method can meet the market demand for testing gold and other elemental contents in major gold alloy products, and is applicable to a wider range of elemental compositions. This method will provide a more effective tool for government market regulation, promote the healthy and long-term development of the market, and offer important technical support for determining the chemical composition of gold alloy products. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0045] Figure 1 The calibration working curve of the relationship between X-ray fluorescence spectrum intensity and gold content constructed by the present invention (Y=-3.102*10 -8 X 2 +5.280*10 -4 X+0.2142);

[0046] Figure 2 The calibration working curve of the relationship between X-ray fluorescence spectrum intensity and silver content constructed by the present invention (Y=-3.582*10 -8 X 2 +1.039*10 -4X+0.0846);

[0047] Figure 3 The calibration working curve diagram of the relationship between X-ray fluorescence spectrum intensity and copper content constructed by the present invention (Y=-1.251*10 -8 X 2 +1.773*10 -4 X+0.0687).

[0048] Figure 4 The calibration working curve diagram of the relationship between X-ray fluorescence spectrum intensity and zinc content constructed by the present invention (Y=-5.758*10 -8 X 2 +2.340*10 -4 X+0.0464).

[0049] Figure 5 The calibration working curve diagram of the relationship between X-ray fluorescence spectrum intensity and nickel content constructed by the present invention (Y=-8.699*10 -8 X 2 +2.461*10 -4 X+0.0297).

[0050] Figure 6 The calibration working curve of the relationship between X-ray fluorescence spectrum intensity and iron content constructed by the present invention (Y=-4.046*10 -8 X 2 +1.345*10 -4 X+0.0151).

[0051] Figure 7 The calibration working curve of the relationship between X-ray fluorescence spectrum intensity and manganese content constructed by the present invention (Y = -5.181*10 -8 X 2 +1.717*10 -4 X+0.0224).

[0052] Figure 8 The calibration working curve diagram of the relationship between X-ray fluorescence spectrum intensity and chromium content constructed by the present invention (Y=-3.370*10 -8 X 2 +7.026*10 -4 X+0.0114). DETAILED DESCRIPTION

[0053] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with specific embodiments.

[0054] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0055] The various types of gold alloy products used in the embodiments of the present invention were provided by enterprises, and their element contents were determined using existing national standards; the X-ray fluorescence spectrometer was a Skyray Instruments EDX3000Plus; and the chemical reagents used were all analytically pure reagents.

[0056] Example 1

[0057] The method for determining the content of gold, silver, copper, zinc, nickel, iron, manganese and chromium in gold alloy products using X-ray fluorescence spectrometry comprises the following steps:

[0058] (1) Accurately weigh a standard metal sample with a content greater than 99.99%, including gold (0.96392 g), copper (0.59763 g), zinc (0.17960 g), nickel (0.12564 g), iron (0.14738 g), and manganese (0.10473 g), add 10 mL of mixed acid (hydrochloric acid and nitric acid in a volume ratio of 5:1), and heat to dissolve at 90°C. After the sample solid is completely dissolved, cool to about 50°C.

[0059] Accurately weigh silver (0.26175 g) and dissolve it in 2 mL of nitric acid solution (the volume ratio of nitric acid to water is 1:1) at room temperature. Slowly add analytical grade hydrochloric acid (150 mL) solution, heat to a slight boil to prepare a clear solution, and cool to 50°C at room temperature. Accurately weigh chromium (0.11091 g) and place it in a beaker. Add 2 mL of hydrochloric acid solution (the volume ratio of hydrochloric acid to water is 1:1) and heat at 60°C to dissolve the sample.

[0060] The dissolved sample was mixed and evenly dispersed by ultrasonic vibration. 2 g of disodium ethylenediaminetetraacetic acid, 2 g of oxalic acid, 1 g of tartaric acid, and 1 mL of perchloric acid were added. The volume was made up to 250 mL with hydrochloric acid solution (hydrochloric acid:water volume ratio of 1:1) to obtain a stable standard stock solution. A calibration blank solution was prepared under the same conditions.

[0061] The study found that under the stable coexistence conditions of gold, silver, copper, zinc, nickel, iron, manganese and chromium, due to the high content of silver, copper and gold, other chemical reagents need to be added, such as disodium ethylenediaminetetraacetic acid, oxalic acid, tartaric acid and perchloric acid, to improve the stability and solubility of their ions or compounds; in addition, the addition of perchloric acid can make the target ions in a high valence state, increase the number of charges, increase hydrophilicity, and improve solubility. In addition, perchloric acid has coordination ability with ions, and the solubility of the target substance is improved by introducing hydrophilic anions, thereby ensuring the stability of the coexisting ion solution system.

[0062] (2) Accurately pipette 10.00 mL, 5.00 mL, 2.00 mL, 1.00 mL, 0.50 mL, and 0.20 mL of the standard stock solution prepared in step (1), respectively, and dilute to 50 mL with hydrochloric acid solution (hydrochloric acid: water volume ratio is 1:1, and the solution contains 2% by mass of disodium ethylenediaminetetraacetic acid, 2% oxalic acid, 1% tartaric acid, and 1% by volume of perchloric acid). Prepare the calibration blank solution in the same manner. The concentrations of each element in the standard solution are shown in Table 1.

[0063] Table 1 Concentration of each element in the standard solution

[0064]

[0065] X-ray fluorescence spectroscopy test conditions are as follows:

[0066] The test conditions for gold are: characteristic spectrum line Lα 9.711 KeV, test time 90 s, X-ray excitation tube voltage 42 kV, X-ray excitation tube current 380 μA, collimation diameter: 8 mm;

[0067] The test conditions for silver are: characteristic spectrum line Kα 22.104 KeV, test time 90 s, X-ray excitation tube voltage 45 kV, X-ray excitation tube current 400 μA, collimation diameter: 8 mm;

[0068] The test conditions for copper are: characteristic spectrum line Kα 8.041 KeV, test time 90 s, X-ray excitation tube voltage 40 kV, X-ray excitation tube current 350 μA, collimation diameter: 8 mm;

[0069] The test conditions for zinc are: characteristic spectrum line Kα 8.631 KeV, test time 90 s, X-ray excitation tube voltage 40 kV, X-ray excitation tube current 350 μA, collimation diameter: 8 mm;

[0070] The test conditions for nickel are: characteristic spectrum line Kα 7.742 KeV, test time 90 s, X-ray excitation tube voltage 38 kV, X-ray excitation tube current 380 μA, collimation diameter: 8 mm;

[0071] The test conditions for iron are: characteristic spectrum line Kα 6.400 KeV, test time 90 s, X-ray excitation tube voltage 38 kV, X-ray excitation tube current 380 μA, collimation diameter: 8 mm;

[0072] The test conditions for manganese are: characteristic spectrum line Kα 5.895 KeV, test time 90 s, X-ray excitation tube voltage 38 kV, X-ray excitation tube current 380 μA, collimation diameter: 8 mm;

[0073] The test conditions for chromium are: characteristic spectrum line Kα 5.411 KeV, test time 90 s, X-ray excitation tube voltage 38 kV, X-ray excitation tube current 380 μA, collimation diameter: 8 mm;

[0074] The full-area peak-to-background ratio background range selected for the eight element tests is: 15KeV to 21KeV for gold, copper, and iron; 16KeV to 20KeV for zinc, nickel, manganese, and chromium; and 26KeV to 36KeV for silver.

[0075] According to the content of each element in the standard solution in Table 1, a relationship diagram between content and intensity was constructed. The results showed that the X-ray fluorescence spectrum intensity of gold, silver, copper, zinc, nickel, iron, manganese and chromium elements showed an obvious linear correlation with the concentration change of the target in the standard solution. Figure 1-8 The results in the figure show that the linear correlation coefficient of the constructed calibration working curves for gold, silver, copper, zinc, nickel, iron, manganese, and chromium elements is greater than 0.999. At the same time, the optimal test conditions for each element were explored through experiments, laying the foundation for the detection of gold, silver, copper, zinc, nickel, iron, manganese, and chromium content in gold alloy products.

[0076] According to the optimal measurement conditions, the accuracy and stability of the measurement of the present invention were evaluated by the spiked recovery rate and the measurement standard deviation. The spiked recovery rate measurement results are shown in Table 2, and the measurement stability measurement results are shown in Table 3.

[0077] Table 2 Spiked recovery of different spiked concentrations of each element

[0078]

[0079]

[0080] Table 3 Measurement stability of different concentrations of each element

[0081]

[0082] The research results show that the spiked recovery rate of high content is between 95% and 105%. According to the statistical rules of data and the accuracy requirements of laboratory test results, the error of the test results meets the requirement of less than 5%. The spiked recovery rate of low content is lower than 95% or higher than 105%, indicating that the error of this method is large at low content measurement accuracy, but the measurement accuracy is significantly improved with the increase of content. Combined with the concentration range of the calibration working curve, the applicable range of this method for gold, silver, copper, zinc, nickel, iron, manganese and chromium elements is based on the spiked recovery rate of the mixed solution in various concentration ranges tested and the target values ​​of the standard samples. The content range of the substances is given as follows: gold content range: 0.15~99.00%, iron content range: 0.12~15.00%, nickel content range: 0.12~12.00%, copper content range: 0.13~60.00%, zinc content range: 0.12~11.00%, silver content range, 0.16~26.00%, chromium content range: 0.12~10.00%, manganese content range: 0.12~10.00%. However, the measurement range of this method is not limited to this range, and measurements beyond this range require relevant experimental verification.

[0083] Example 2

[0084] According to the sample pretreatment conditions and the established test method of Example 1, representative gold alloy samples were selected from the market, including two 18K gold products (sample numbers 1 and 2), one each of 74 gold foil and 96 gold foil (sample numbers 3 and 4), one pure gold product (sample number 5), and one 22K gold product (sample number 6).

[0085] The gold content is determined by the national standard GB / T 9288-2019, the gold alloy samples with silver content less than 5% are determined by the national standard GB / T 40114-2021, the gold alloy samples with silver content greater than 15% are determined by the national standard GB / T15072.5-2008, nickel and zinc (0.5-6%) and manganese (0.01-0.5%) are determined by the national standard GB / T15072.15-2008, copper and manganese (0.5-6%) are determined by the national standard GB / T15072.16-2008, copper (4-35%) is determined by the national standard GB / T 15072.8-2008, nickel (5-20%) is determined by the national standard GB / T15072.10-2008, low content of copper, nickel, iron, zinc, chromium and manganese is determined by the national standard GB / T 40114-2021 national standard for measurement.

[0086] The method of the present invention was used to prepare stable sample solutions and blank solutions for the gold alloy samples selected above, and the content of each element was tested. The results were compared with the test results of the currently effective standard method. The measurement results are shown in Table 4.

[0087] Table 4 Determination of gold, silver, copper, zinc, nickel, iron, manganese and chromium content in 6 gold alloy samples by this method

[0088]

[0089]

[0090] The measurement results in Table 4 show that the X-ray fluorescence spectrometry standard working curve constructed in the present invention can be used to determine the content of gold, silver, copper, zinc, nickel, iron, manganese, and chromium in gold alloy products, especially for samples with content above the detection limit. The measurement results are highly consistent with the values ​​measured by the national standard method, indicating that this method can be used as a new detection method for the rapid and accurate determination of the content of gold, silver, copper, zinc, nickel, iron, manganese, and chromium in gold alloy products. For elements with content below the detection limit, the measurement accuracy and stability of this method are poor, and it cannot meet the requirements for element measurement in gold alloy products.

[0091] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art will be able to modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein with equivalents. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A method for determining the gold content and other element contents in a gold alloy product, characterized in that: The steps include: (1) Weigh a certain mass of gold alloy sample, dissolve the sample in a mixed acid solution of hydrochloric acid and nitric acid, add appropriate amounts of hydrochloric acid, disodium ethylenediaminetetraacetic acid, oxalic acid, tartaric acid, and perchloric acid to prepare a stable sample solution, and adjust the volume with hydrochloric acid and water; wherein the volume ratio of hydrochloric acid to water is not less than 1:1; (2) According to the gold content and other element content ranges of different types of gold alloy products, weigh an appropriate amount of pure metal samples of gold, silver, copper, zinc, nickel, iron, manganese, and chromium with a purity greater than 99.99% and place them in a beaker; Gold, copper, zinc, nickel, iron, and manganese are dissolved in a mixed acid solution of hydrochloric acid and nitric acid; silver is dissolved in a nitric acid solution at room temperature, and then slowly added with a hydrochloric acid solution, and heated to a slight boil to prepare a clear solution; chromium is added with a hydrochloric acid solution and heated to dissolve; the dissolved samples are mixed, and appropriate amounts of hydrochloric acid, disodium ethylenediaminetetraacetic acid, oxalic acid, tartaric acid, and perchloric acid are added to adjust the solution to ensure the stability of the test solution under the coexistence of gold, silver, copper, zinc, nickel, iron, manganese, and chromium, and the volume is constant to obtain a standard stock solution; an appropriate amount of the standard stock solution is measured to prepare a series of standard solutions for constructing a calibration working curve; (3) Using an X-ray fluorescence spectrometer to measure a series of standard solutions with known gold, silver, copper, zinc, nickel, iron, manganese, and chromium contents, construct a calibration working curve showing the relationship between X-ray fluorescence spectrum intensity and gold, silver, copper, zinc, nickel, iron, manganese, and chromium content, and determine the test conditions for gold, silver, copper, zinc, nickel, iron, manganese, and chromium standard sample elements; (4) According to the gold alloy product sample preparation conditions and the gold, silver, copper, zinc, nickel, iron, manganese, and chromium element test conditions determined in steps (1) to (3), the fluorescence intensity of the target element in the gold alloy product test solution to be tested is measured using an X-ray fluorescence spectrometer. According to the relationship between the X-ray fluorescence spectrum intensity and the gold, silver, copper, zinc, nickel, iron, manganese, and chromium element content in the calibration working curve constructed in step (3), the content of gold, silver, copper, zinc, nickel, iron, manganese, and chromium in the gold alloy jewelry to be tested is calculated using the formula. The target object content calculation formula is: In formula (1): W i %: represents the mass percentage of the target element i; V: represents the constant volume of the sample solution to be tested, in mL; m: represents the weight of the sample to be tested, in g; C i : Indicates the concentration of the target element read by the instrument test, in g / mL; C0: Indicates the concentration of the target element in the blank test solution read by the instrument test, in g / mL.

2. The method for determining the gold content and other element contents in a gold alloy product according to claim 1, wherein: In step (1), for every 0.2 g to 2.0 g of the gold alloy product, 10 mL to 20 mL of a mixed acid solution of hydrochloric acid and nitric acid is used to dissolve the sample at 80° C. to 120° C., wherein the volume ratio of hydrochloric acid to nitric acid is not less than 5:1; and 1 mL to 50 mL of hydrochloric acid, 1 g to 8 g of disodium edetate, 1 g to 6 g of oxalic acid, 1 g to 4 g of tartaric acid, and 1 mL to 3 mL of perchloric acid are added to prepare a stable sample solution.

3. The method for determining the gold content and other element contents in a gold alloy product according to claim 2, wherein: The step (1) specifically comprises: taking 1.0 g of the gold alloy product and placing it in a beaker, adding 10 mL of a mixed acid solution of hydrochloric acid and nitric acid, wherein the volume ratio of hydrochloric acid to nitric acid is 5:1; heating and dissolving at 90° C., and after the sample solid is completely dissolved, cooling to 50° C., adding 40 mL of analytical pure hydrochloric acid solution, adding 2 g of disodium ethylenediaminetetraacetic acid, 2 g of oxalic acid, 1 g of tartaric acid and 1 mL of perchloric acid, and diluting the volume to 100 mL with the hydrochloric acid solution to obtain a stable sample solution; wherein the volume ratio of hydrochloric acid to water in the hydrochloric acid solution is 1:1; Follow the same steps to prepare a blank solution.

4. The method for determining the gold content and other element contents in a gold alloy product according to claim 1, wherein: Specifically, step (2) comprises weighing a pure metal sample with a purity greater than 99.99% according to the gold content and other element content ranges in different types of gold alloy products, wherein: 0.8-1.2g gold, 0.22-0.26g silver, 0.50-0.80g copper, 0.10-0.13g zinc, 0.11-0.14g nickel, 0.12-0.16g iron, 0.10-0.12g chromium, and 0.10-0.12g manganese; For gold, copper, zinc, nickel, iron, and manganese, add 10 mL of a mixed acid solution of hydrochloric acid and nitric acid, where the volume ratio of hydrochloric acid to nitric acid is 5:1; heat and dissolve at 90°C, and cool to 50°C until the sample solid is completely dissolved; Silver was dissolved in 2 mL of nitric acid at room temperature, and then analytical grade hydrochloric acid was slowly added. The solution was heated to a slight boil to prepare a clear solution, and then cooled to 50°C at room temperature. Chromium was placed in a beaker, and hydrochloric acid was added. The sample was heated at 60°C to dissolve. The dissolved sample was mixed and evenly dispersed by ultrasonic vibration. 50 mL of analytical grade hydrochloric acid solution was added, followed by 2 g of disodium ethylenediaminetetraacetic acid, 2 g of oxalic acid, 1 g of tartaric acid, and 1 mL of perchloric acid. The volume was adjusted to 250 mL with hydrochloric acid solution to prepare a stable standard stock solution. The volume ratio of hydrochloric acid to water in the hydrochloric acid solution was 1:

1. A calibration blank solution was prepared according to the same steps. An appropriate amount of the standard stock solution was pipetted to prepare a series of standard solutions.

5. The method for determining the gold content and other element contents in a gold alloy product according to claim 4, wherein: Use a pipette to transfer an appropriate amount of standard stock solution to prepare a series of standard solutions. The specific steps are as follows: use a pipette to accurately transfer 10.00mL, 5.00mL, 2.00mL, 1.00mL, 0.50mL, and 0.20mL of the standard stock solution, respectively, and dilute the volume to 50mL with hydrochloric acid solution, wherein the volume ratio of hydrochloric acid to water in the hydrochloric acid solution is 1:1, and the solution contains 2% by mass of disodium ethylenediaminetetraacetic acid, 2% by mass of oxalic acid, and 1% by volume of perchloric acid; use the same method to prepare a calibration blank solution.

6. The method for determining the gold content and other element contents in a gold alloy product according to claim 1, wherein: The test conditions for gold, silver, copper, zinc, nickel, iron, manganese and chromium in step (3) are: The test conditions for gold are: characteristic spectrum line Lα 9.711 KeV, test time 90 s, X-ray excitation tube voltage 42 kV, X-ray excitation tube current 380 μA, collimation diameter: 8 mm; The test conditions for silver are: characteristic spectrum line Kα 22.104 KeV, test time 90 s, X-ray excitation tube voltage 45 kV, X-ray excitation tube current 400 μA, collimation diameter: 8 mm; The test conditions for copper are: characteristic spectrum line Kα 8.041 KeV, test time 90 s, X-ray excitation tube voltage 40 kV, X-ray excitation tube current 350 μA, collimation diameter: 8 mm; The test conditions for zinc are: characteristic spectrum line Kα 8.631 KeV, test time 90 s, X-ray excitation tube voltage 40 kV, X-ray excitation tube current 350 μA, collimation diameter: 8 mm; The test conditions for nickel are: characteristic spectrum line Kα 7.742 KeV, test time 90 s, X-ray excitation tube voltage 38 kV, X-ray excitation tube current 380 μA, collimation diameter: 8 mm; The test conditions for iron are: characteristic spectrum line Kα 6.400 KeV, test time 90 s, X-ray excitation tube voltage 38 kV, X-ray excitation tube current 380 μA, collimation diameter: 8 mm; The test conditions for manganese are: characteristic spectrum line Kα 5.895 KeV, test time 90 s, X-ray excitation tube voltage 38 kV, X-ray excitation tube current 380 μA, collimation diameter: 8 mm; The test conditions for chromium are: characteristic spectrum line Kα 5.411 KeV, test time 90 s, X-ray excitation tube voltage 38 kV, X-ray excitation tube current 380 μA, collimation diameter: 8 mm; The full-area peak-to-background ratio background range selected for the 8 element tests is: 15KeV to 21KeV for gold, copper, and iron; 16KeV to 20KeV for zinc, nickel, manganese, and chromium; and 26KeV to 36KeV for silver.

7. The method for determining the gold content and other element contents in a gold alloy product according to claim 1, wherein: During the measurement process, the thickness of the sample liquid is 5 to 20 mm, and the liquid interface film is a polyethylene material with a thickness of 8 μm.

8. The method for determining the gold content and other element contents in a gold alloy product according to claim 1, wherein: The measurement ranges of eight elements, gold, silver, copper, zinc, nickel, iron, manganese and chromium, are: the measurement range of gold is 0.15~99.00wt%, the measurement range of silver is 0.10~26.00wt%, the measurement range of copper is 0.10~60.00wt%, the measurement range of zinc is 0.10~11.00wt%, the measurement range of nickel is 0.10~12.00wt%, the measurement range of iron is 0.10~15.00wt%, the measurement range of manganese is 0.10~10.00wt%, and the measurement range of chromium is 0.10~10.00wt%.

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