Quantitative detection method for deuterated methanol and deuterated ethanol

Abstract

The invention provides a quantitative detection method of deuterated methanol and deuterated ethanol, and relates to the technical field of detection and analysis of deuterated compounds. The detection method adopts a gas chromatographic analysis method, has excellent separation capability and anti-interference performance, and can effectively avoid the peak overlapping problem between a target object and other volatile components; meanwhile, in combination with an internal standard method, the influence caused by chromatographic condition fluctuation, chromatographic column performance change and unstable sample size can be effectively counteracted, and the dependence on frequent drawing of a standard curve is remarkably reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of deuterated compound detection and analysis, and in particular to a quantitative detection method for deuterated methanol and deuterated ethanol. Background Art

[0002] Deuterated methanol and deuterated ethanol are important, high-value-added chemicals widely used in high-end scientific research and industrial fields such as medicine, materials science, and nuclear magnetic resonance analysis. Due to their complex synthesis processes, high technical barriers, and high production costs, they place extremely high demands on product purity and quantitative testing. In actual production and quality control, rapid and accurate content determination is key to ensuring product quality and improving production efficiency.

[0003] Currently, the quantitative detection of these deuterated compounds primarily relies on nuclear magnetic resonance (NMR) technology. While this method offers good accuracy and reproducibility, its high equipment cost, cumbersome sample pretreatment, and large sample volumes are required. Furthermore, the deuterated solvent itself can dilute the target concentration, limiting its widespread adoption within general production facilities. Infrared spectroscopy (IR) can also be used for quantitative analysis, but due to its susceptibility to ambient temperature and humidity, it suffers from baseline drift and nonlinear response, resulting in low detection limits and the need for frequent calibration, making it difficult to meet the demands of high-precision detection.

[0004] Therefore, there is an urgent need to develop an alternative analytical method that is simple to operate, highly sensitive, has strong anti-interference ability, and is suitable for routine laboratory conditions to achieve the quantitative detection of deuterated methanol and deuterated ethanol. Summary of the Invention

[0005] In view of this, the present invention proposes a quantitative detection method for deuterated methanol and deuterated ethanol, which uses gas chromatography analysis combined with an internal standard method, which not only effectively improves the accuracy of the quantitative detection results, but also meets the needs of rapid and automated sample analysis.

[0006] The technical solution of the present invention is achieved as follows: The present invention provides a method for quantitatively detecting deuterated methanol and deuterated ethanol, comprising the following steps: The sample to be tested is injected into the gas chromatograph. After being vaporized in the vaporization chamber, the sample is carried into the chromatographic column by the carrier gas. The components in the sample are separated in the chromatographic column and flow out of the chromatographic column into the hydrogen flame ionization (FID) detector. The detector identifies and responds to the sample flowing out of the column. The data processing system converts the detector signal into a chromatogram for quantitative analysis. Wherein, the detection conditions of the gas chromatograph include: The detection temperature of the hydrogen flame ionization FID detector is: 200~250℃; the injection port temperature is: 230~250℃; the air flow rate is 270~330mL / min; the hydrogen flow rate is 27~33mL / min; the column flow rate is 1~2mL / min, and the split ratio is 10:1~100:1.

[0007] Furthermore, the temperature program of the gas chromatograph is set as follows: the initial column temperature is 40~60℃, the holding time is 2~5min, the temperature is increased to 120℃ at a rate of 5~10℃ / min, the holding time is 2~5min, and then the temperature is increased to 180℃ at a rate of 10~20℃ / min, and the holding time is 2~12min.

[0008] Furthermore, the chromatographic column is selected from one of a strong polarity capillary column, a medium polarity capillary column or a weak polarity capillary column.

[0009] Specifically, further, the model of the capillary column is selected from one of DB-WAX, PoraPLOT U, DB-624, TG-624, OV-624, HP-624, RTX-624, SPB-624, AT-624, ZM-624, BP-624, TR-V1, DB-1301, Rtx-1301, PE-1301, HP-1301, OV-1301 or SPB-1301.

[0010] Specifically, further, the stationary phase of the capillary column is selected from one of polyethylene glycol, cyanopropylsiloxane, styrene-divinylbenzene, 50% phenyl-50% methylpolysiloxane, 35% phenyl-65% methylpolysiloxane, 5% phenyl-95% methylpolysiloxane or 6% cyanopropylphenyl-94% polydimethylsiloxane.

[0011] Furthermore, the stationary phase of the capillary column is selected from one of styrene-divinylbenzene, 5% phenyl-95% methylpolysiloxane or 6% cyanopropylphenyl-94% polydimethylsiloxane.

[0012] Furthermore, the analysis method is an internal standard method, and the internal standard is selected from one of tetrahydrofuran or n-hexane.

[0013] Furthermore, the detection conditions of the gas chromatograph also include: a septum purge gas flow rate of 3 mL / min, a tail gas flow rate of 25 mL / min, and an injection volume of 1 μL.

[0014] The quantitative detection method of deuterated methanol and deuterated ethanol of the present invention has the following beneficial effects compared with the prior art: (1) The quantitative detection method of the present invention adopts gas chromatography analysis, which has excellent separation ability and anti-interference properties, and can effectively avoid the peak overlap problem between the target compound and other volatile components. At the same time, combined with the internal standard method, it can effectively offset the effects of fluctuations in chromatographic conditions, changes in chromatographic column performance, and unstable injection volume, significantly reducing the reliance on frequent drawing of standard curves.

[0015] (2) The quantitative detection method of the present invention has high sensitivity and low sample consumption. A single injection requires only 1 μL of sample to achieve a detection limit of ppm. In addition, the detection method has good system stability. Combined with the programmable temperature control of the column oven, it is not affected by the ambient temperature and humidity, and the quantitative accuracy is higher, with the relative error being controlled within 1%.

[0016] (3) The quantitative detection method of the present invention can be fully automated and is suitable for the high-efficiency detection needs of large-scale production in enterprises. After the injection sequence is set, no manual supervision is required, which greatly improves the detection efficiency and throughput. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0018] Figure 1 This is a typical chromatogram of the test solution prepared in Example 1 of the present invention; Figure 2 : This is the quantitative standard curve of Example 1 of the present invention. In the figure, (a) is the quantitative standard curve of deuterated methanol, and (b) is the quantitative standard curve of deuterated ethanol; Figure 3 This is a typical chromatogram of the test solution prepared in Example 2 of the present invention; Figure 4 This is the quantitative standard curve of Example 2 of the present invention. In the figure, (a) is the quantitative standard curve of deuterated methanol, and (b) is the quantitative standard curve of deuterated ethanol. DETAILED DESCRIPTION

[0019] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0020] In view of the limitations of existing nuclear magnetic resonance and infrared spectroscopy for quantitative detection of deuterated compounds, the inventors made the present invention through further experiments and exploration.

[0021] Gas chromatography, due to its advantages such as high separation efficiency, rapid analysis, and excellent sensitivity, has been widely used in the qualitative and quantitative analysis of organic compounds. It is particularly well-suited for highly volatile compounds such as deuterated methanol and deuterated ethanol. However, in practical applications, selecting the appropriate quantitative method to improve the accuracy and stability of detection results remains a major challenge.

[0022] Currently, the most commonly used quantification method is the external standard method. However, this method has numerous limitations in the detection of deuterated methanol and deuterated ethanol. Firstly, the external standard method places extremely high demands on the purity, preparation precision, and injection reproducibility of the external standard. Insufficient standard purity or inconsistent injection volume will directly lead to biased quantitative results. Secondly, even slight fluctuations in experimental conditions such as column temperature, carrier gas flow rate, and inlet temperature can cause shifts in retention time and peak area, affecting the stability of the standard curve. Declining column performance over time further exacerbates this uncertainty. Furthermore, the external standard method suffers from poor analytical efficiency. Each measurement requires simultaneous injection of a standard for calibration, significantly increasing time and labor costs, especially when testing batches of samples. Furthermore, it cannot effectively compensate for interference effects from complex matrices. Due to its limited linear range, when sample concentrations are too high or too low and exceed the applicable range of the standard curve, the concentration must be readjusted or the standard curve must be replaced, increasing operational complexity. Finally, the accuracy of the results obtained with the external standard method is highly dependent on instrument status. For example, changes in FID detector sensitivity over time can render the standard curve invalid, necessitating frequent calibration to maintain detection reliability.

[0023] Therefore, the inventors combined the high separation capability of gas chromatography and the quantitative advantages of the internal standard method to propose a quantitative detection method for deuterated methanol and deuterated ethanol that is more suitable for actual production scenarios, so as to overcome the shortcomings of the existing technology and improve the accuracy, stability and efficiency of detection.

[0024] The present invention will be further described below with reference to specific examples, but the scope of protection of the present invention is not limited by the following examples. Unless otherwise specified, the materials mainly involved in the following examples are conventional commercial products.

[0025] Example 1 This embodiment provides a method for quantitatively detecting deuterated methanol and deuterated ethanol, comprising: (1) Instruments and materials PerkingElmer GC2400 gas chromatograph (purchased from PerkinElmer, USA) equipped with a flame ionization detector (FID, detection limit ≤1 pg C / s (n-hexadecane)) and a split / splitless flow device (SPL); Chromatographic column: A highly polar chromatographic column, model Agilent J&W PoraPLOT U (purchased from Agilent Technologies, USA), with a length of 25 m and an inner diameter of 0.32 mm was selected. The stationary phase was styrene-divinylbenzene with a particle size of 10 μm; 100 μL pipette (purchased from Dalong Xingchuang Laboratory Instrument (Beijing) Co., Ltd., China); 1000 μL pipette (purchased from Dalong Xingchuang Laboratory Instrument (Beijing) Co., Ltd., China); 1 / 10,000 balance (purchased from Mettler-Toledo Instruments (Shanghai) Co., Ltd., China); deuterated methanol (CD3OD, purity ≥99.5%, Cambridge Isotope Laboratories); Deuterated ethanol (C2D5OD, purity ≥99.5%, Sigma-Aldrich); Internal standard: tetrahydrofuran (HPLC grade, stabilized with 0.025% BHT, Tedia); Dilution solvent: ultrapure water (resistivity ≥ 18.2 MΩ·cm); (2) Preparation of standard samples Eight sets of standard samples were prepared using deuterated methanol (CD3OD), deuterated ethanol (C2D5OD), and tetrahydrofuran as raw materials. Different volumes were weighed and mixed to prepare the sample solution. 0.1 mL of tetrahydrofuran was added to each sample as an internal standard and mixed thoroughly to obtain the test solution. The amounts of each component are shown in Table 1 below: Table 1

[0026] (3) Gas chromatography conditions Inlet temperature: 200°C; Hydrogen flame detector temperature: 230°C; Heating program: initial temperature 40℃, hold for 2 min; heat to 120℃ at 10℃ / min, hold for 3 min; then heat to 180℃ at 20℃ / min, hold for 12 min.

[0027] Column flow rate (helium): 2 mL / min; Septum purge: 3 mL / min; Air flow rate: 300mL / min; Hydrogen flow rate: 30mL / min; Make-up gas flow rate: 25mL / min; Split ratio: 50:1; Injection volume: 1 μL; Through the above chromatographic conditions, the Figure 1 The chromatogram shown.

[0028] Depend on Figure 1 It can be seen that deuterated methanol peaks at 11.241 min, deuterated ethanol peaks at 13.281 min, and internal standard tetrahydrofuran peaks at 15.976 min.

[0029] (4) Establishing the standard curve equation a. Deuterated methanol standard curve A standard curve was drawn with the mass of deuterated methanol / the mass of tetrahydrofuran as the abscissa (x) and the peak area of ​​deuterated methanol / the peak area of ​​tetrahydrofuran as the ordinate (y). The linear correlation equation of deuterated methanol was established, as shown in the following formula (I): y = 0.4878x + 0.0159 (I), linear correlation coefficient R 2 = 0.9976; b. Deuterated ethanol standard curve A standard curve was drawn with the mass of deuterated ethanol / the mass of tetrahydrofuran as the abscissa (x) and the peak area of ​​deuterated ethanol / the peak area of ​​tetrahydrofuran as the ordinate (y). The linear correlation equation of deuterated ethanol was established, as shown in the following formula (II): y = 0.7115x + 0.0418 (Ⅱ), linear correlation coefficient R 2 = 0.999.

[0030] The quantitative standard curves of deuterated methanol and deuterated ethanol are shown in Figure 2 (a) and (b) in the figure show good linear relationship and are suitable for quantitative analysis.

[0031] (5) Accuracy verification (analysis of test samples) ①Preparation of samples to be tested Take 0.9 mL of a mixed sample of deuterated methanol and deuterated ethanol of unknown concentration, add 0.1 mL of tetrahydrofuran as internal standard, and mix well to obtain the test solution.

[0032] ②GC-FID analysis Analyze according to the chromatographic conditions described in step (3).

[0033] ③Data processing and evaluation According to the GC-FID analysis results, the following results were obtained: The peak area of ​​deuterated methanol is A CD3OD =67579 The peak area of ​​tetrahydrofuran is A THF =30214 The peak area of ​​deuterated ethanol is A C2D5OD =76301 Substituting into the standard curve equation in (4), we can calculate: Deuterated methanol: y = A CD3OD / A THF =67579 / 30214=2.24Substituted into formula (I), we get x≈4.55; by the same token, we can get deuterated ethanol x≈3.49.

[0034] The density of tetrahydrofuran is approximately 0.887 g / mL, so the mass of tetrahydrofuran added is 0.0887 g; According to the mass ratio x, the actual mass of deuterated methanol is 0.4045 g, and the actual mass of deuterated ethanol is 0.3103 g; According to the mass of the deuterated compound, the concentration of deuterated methanol is 0.449 g / mL, and the concentration of deuterated ethanol is 0.3448 g / mL.

[0035] (6) Repeatability and precision evaluation Select at least three standard samples with different concentration levels, repeat the injection of each sample at least three times, record the peak area, and calculate the average value and RSD.

[0036] Deuterated methanol RSD%: ≤1.5%; deuterated ethanol RSD%: ≤1.2%; no outliers were found.

[0037] (7) Recovery rate test Deuterated methanol: 98.5%~101.2%; Deuterated ethanol: 99.1%~102.0%.

[0038] This example establishes a quantitative detection method for deuterated methanol and deuterated ethanol based on GC-FID technology, which has good linear correlation and accuracy and is suitable for the simultaneous detection and quantitative analysis of the two compounds in actual samples.

[0039] Comparative Example 1 This comparative example provides a quantitative detection method for deuterated methanol and deuterated ethanol, which uses gas chromatography combined with an external standard method, including: (1) Instruments and materials Same as Example 1, but without internal standard.

[0040] (2) Preparation of standard samples Eight sets of standard samples were prepared using deuterated methanol (CD3OD) and deuterated ethanol (C2D5OD) as raw materials, mixing different volumes. The amounts of deuterated methanol and deuterated ethanol used in each set are shown in Table 1.

[0041] (3) Gas chromatography conditions, same as in Example 1 (4) Establish the external standard curve equation a. Deuterated methanol standard curve With the mass concentration of deuterated methanol (%) as the abscissa (x) and the corresponding peak area as the ordinate (y), a standard curve was drawn and a linear equation was fitted, as shown below: y = 113243x -418.04, linear correlation coefficient R 2 = 0.9923; b. Deuterated ethanol standard curve With the mass concentration of deuterated ethanol (%) as the abscissa (x) and the corresponding peak area as the ordinate (y), a standard curve was drawn and a linear equation was fitted, as shown below: y =162810x+406.54, linear correlation coefficient R 2 = 0.9915.

[0042] (5) Accuracy verification (analysis of test samples) ① Preparation of samples to be tested Take 1 g of a mixed sample of deuterated methanol and deuterated ethanol of unknown concentration.

[0043] ② GC-FID analysis Perform analysis according to the chromatographic conditions described in step (3), and record the peak times and peak areas of deuterated methanol and deuterated ethanol.

[0044] ③ Data processing and evaluation According to the GC-FID analysis results, the following results were obtained: The peak area of ​​deuterated methanol is A CD3OD =93428 The peak area of ​​deuterated ethanol is A C2D5OD =28295 Substituting into the standard curve equation in (4), we can calculate: Deuterated methanol: y = A CD3OD =93428Substituted into the above formula, we get x≈82.87%; by the same token, we can get deuterated ethanol x≈17.13%.

[0045] According to the mass of the deuterated compound, the mass of deuterated methanol is 0.8287 g, and the mass of deuterated ethanol is 0.1713 g.

[0046] (6) Repeatability and precision evaluation Taking samples 1 to 5 as an example, repeat the injection at least three times, record the peak area, and calculate the average value and RSD.

[0047] Deuterated methanol RSD%: 2.8~4.1%; deuterated ethanol RSD%: 3.2~5.0%; 2 outliers occurred.

[0048] (7) Recovery rate test Deuterated methanol: 96.3%~103.7%; Deuterated ethanol: 95.8%~104.5%.

[0049] By comparing the results obtained by the external standard method in comparative example 1 with the results obtained by the internal standard method in Example 1, it can be found that: first, the linear correlation coefficient of Example 1 is higher (R²>0.997), while the linear correlation coefficient of comparative example R 2 The relative standard deviations (RSDs) of the internal standard method were generally lower than 0.995, indicating that the linear correlation coefficient of the internal standard method was significantly higher than that of the external standard method, indicating that the standard curve of the internal standard method was closer to the ideal linear relationship and less affected by systematic errors. Secondly, the relative standard deviation (RSD) of the internal standard method was significantly lower than that of the external standard method, indicating better reproducibility and more stable results. The external standard method had a higher RSD and the presence of outliers, indicating a greater dependence on experimental conditions. Finally, the recovery of the internal standard method was closer to 100%, indicating higher quantitative accuracy; the recovery range of the external standard method was wider, which may be due to matrix effects or injection errors.

[0050] In summary, the external standard method is greatly affected by factors such as injection volume fluctuations and instrument drift, which may lead to the reproducibility and accuracy of the results being inferior to the internal standard method. The internal standard method can show better stability and precision, especially in terms of errors that may be introduced during sample pretreatment.

[0051] Example 2 This embodiment provides a method for quantitatively detecting deuterated methanol and deuterated ethanol, comprising: (1) Instruments and materials (Except for the following, other conditions are the same as those in Example 1) Chromatographic column: A mid-polarity column, model DB-624 (purchased from Agilent Technologies, USA), with a length of 60 m and an inner diameter of 0.32 mm was selected. The stationary phase was 6% cyanopropylphenyl and 94% polydimethylsiloxane, with a particle size of 1.8 μm; Internal standard: n-hexane (HPLC grade) Dilution solvent: ultrapure water (resistivity ≥ 18.2 MΩ·cm); (2) Preparation of standard samples Eight sets of standard samples were prepared using deuterated methanol (CD3OD), deuterated ethanol (C2D5OD), and n-hexane as raw materials. Different volumes were weighed and mixed to prepare the sample solutions. 0.1 mL of n-hexane was added to each sample as an internal standard and mixed thoroughly to obtain the test solution. The amounts of deuterated methanol and deuterated ethanol used in each set are shown in Table 1.

[0052] (3) Gas chromatography conditions Inlet temperature: 250°C; Hydrogen flame detector temperature: 250°C; Heating program: initial temperature 40℃, hold for 2 min; heat to 120℃ at 10℃ / min, hold for 3 min; heat to 180℃ at 20℃ / min, hold for 7 min.

[0053] Column flow rate (helium): 2 mL / min; Septum purge: 3 mL / min; Air flow rate: 300mL / min; Hydrogen flow rate: 30mL / min; Make-up gas flow rate: 25mL / min; Split ratio: 50:1; Injection volume: 1 μL; Through the above chromatographic conditions, the Figure 3 The chromatogram shown.

[0054] Depend on Figure 3 It can be seen that deuterated methanol peaks at 5.4 min, deuterated ethanol peaks at 6.514 min, and internal standard n-hexane peaks at 8.251 min.

[0055] (4) Establishing the standard curve equation a. Deuterated methanol standard curve A standard curve was drawn with the mass of deuterated methanol / the mass of normal hexane as the abscissa (x) and the peak area of ​​deuterated methanol / the peak area of ​​normal hexane as the ordinate (y). The linear correlation equation of deuterated methanol was established, as shown in the following formula (III): y = 0.3287x + 0.025 (III), linear correlation coefficient R 2 = 0.9999; b. Deuterated ethanol standard curve A standard curve was drawn with the mass of deuterated ethanol / the mass of normal hexane as the abscissa (x) and the peak area of ​​deuterated ethanol / the peak area of ​​normal hexane as the ordinate (y). The linear correlation equation of deuterated ethanol was established, as shown in the following formula (IV): y = 0.5364x-0.1657 (IV), linear correlation coefficient R 2 = 0.9911.

[0056] The quantitative standard curves of deuterated methanol and deuterated ethanol are shown in Figure 4 (a) and (b) in the figure show good linear relationship and are suitable for quantitative analysis.

[0057] (5) Accuracy verification ①Preparation of samples to be tested Take 0.9 mL of a mixed sample of deuterated methanol and deuterated ethanol of unknown concentration, add 0.1 mL of n-hexane as internal standard, and mix thoroughly to obtain the test solution.

[0058] ②GC-FID analysis Inject and analyze the sample according to the chromatographic conditions described in step (3).

[0059] ③Data processing and evaluation According to the GC-FID analysis results, the following results were obtained: The peak area of ​​deuterated methanol is A CD3OD =38509 The peak area of ​​n-hexane is A Hexane =23790 The peak area of ​​deuterated ethanol is A C2D5OD =70557 Substituting into the standard curve equation in (4), we can calculate: Deuterated methanol: y = A CD3OD / A Hexane =38509 / 23790=1.618Substitute into formula (III) to get x≈4.85; Similarly, deuterated ethanol x≈5.84; The density of n-hexane is approximately 0.659 g / mL, so the mass of n-hexane added is 0.0659 g; According to the mass ratio x, the actual mass of deuterated methanol is 0.3194 g, and the actual mass of deuterated ethanol is 0.3847 g; According to the mass of the deuterated compounds, the concentration of deuterated methanol is 0.3549 g / mL, and the concentration of deuterated ethanol is 0.4274 g / mL; (6) Stability verification Taking sample 4 as an example, it was divided into three groups, with 3 parallel samples in each group, for stability testing, recorded as sample 4A (1, 2, 3), sample 4B (1, 2, 3) and sample 4C (1, 2, 3), including: ① Daily stability: Store sample 4A at room temperature (25°C); ② Short-term stability: Store sample 4B in a refrigerator at 4°C. ③ Long-term stability: Store sample 4C in a -20℃ refrigerator; ④ Take samples for GC-FID analysis at 0h (i.e., immediately after preparation), 4h, 8h, 24h, 48h, and 7 days; ⑤ Each time a sample is taken, analyze it according to the gas chromatography detection conditions in (3) and record the peak areas of deuterated methanol, deuterated ethanol and its internal standard n-hexane, which are respectively recorded as A CD3OD 、A C2D5OD 、AHexane ; ⑥Data processing and evaluation i. Peak area ratio calculation (relative peak area ratio method) R (deuterated methanol) = A CD3OD / A Hexane R (deuterated ethanol) = A C2D5OD / A Hexane ii. Relative deviation RD(%)=(R t -R0) / R0×100%, where R t is the peak area ratio at time point t, and R0 is the peak area ratio at the initial time point; The experimental results shown in Table 2 are obtained; Table 2 Experimental results of sample 4A (1, 2, 3) (I)

[0060] Table 2 Experimental results of sample 4B (1, 2, 3) (II)

[0061] Table 2 Experimental results of sample 4C (1, 2, 3) (III)

[0062] ⑦Result analysis The experimental data in Table 2 above show that after storage at room temperature for more than 24 hours, the peak area ratio of the deuterated compound in the sample gradually decreases over time, indicating instability at room temperature. In contrast, the relative deviations for samples stored at refrigerated (4°C) and frozen (-20°C) remained within ±5% throughout the entire observation period, demonstrating excellent stability. Therefore, for short-term storage, room temperature storage is recommended; for medium- to long-term storage, refrigeration at 4°C or freezing at -20°C is recommended.

[0063] This example establishes a quantitative detection method for deuterated methanol and deuterated ethanol based on GC-FID technology, which has good linear correlation and stability and is suitable for the simultaneous detection and quantitative analysis of the two compounds in actual samples.

[0064] Example 3 This embodiment provides a method for quantitatively detecting deuterated methanol and deuterated ethanol, comprising: (1) Instruments and materials (Except for the following, other conditions are the same as those in Example 1) Chromatographic column: A weak polarity chromatographic column, model HP-1301 chromatographic column (purchased from Agilent Technologies, USA), with a length of 30 m and an inner diameter of 0.32 mm was selected; The stationary phase was 5% phenyl-95% methylpolysiloxane with a particle size of 0.25 μm; Internal standard: n-hexane (HPLC grade) Dilution solvent: ultrapure water (resistivity ≥ 18.2 MΩ·cm); (2) Preparation of standard samples Eight sets of standard samples were prepared using deuterated methanol (CD3OD), deuterated ethanol (C2D5OD), and n-hexane as raw materials. Different volumes were weighed and mixed to prepare the sample solutions. 0.1 mL of n-hexane was added to each sample as an internal standard and mixed thoroughly to obtain the test solution. The amounts of deuterated methanol and deuterated ethanol used in each set are shown in Table 1.

[0065] (3) Gas chromatography conditions Inlet temperature: 240°C; Hydrogen flame detector temperature: 220℃; Heating program: initial temperature 50℃, hold for 3 min; heat to 120℃ at 10℃ / min, hold for 2 min; heat to 180℃ at 20℃ / min, hold for 12 min.

[0066] Column flow rate (helium): 2 mL / min; Septum purge: 3 mL / min; Air flow rate: 320mL / min; Hydrogen flow rate: 32 mL / min; Make-up gas flow rate: 25mL / min; Split ratio: 50:1; Injection volume: 1 μL; Under the above chromatographic conditions, it was found that deuterated methanol peaked at 8.3 min, deuterated ethanol peaked at 9.7 min, and internal standard n-hexane peaked at 11.5 min.

[0067] (4) Establishing the standard curve equation a. Deuterated methanol standard curve A standard curve was drawn with the mass of deuterated methanol / the mass of normal hexane as the abscissa (x) and the peak area of ​​deuterated methanol / the peak area of ​​normal hexane as the ordinate (y). The linear correlation equation of deuterated methanol was established as shown below: y = 0.3054x + 0.012, linear correlation coefficient R 2 = 0.998; b. Deuterated ethanol standard curve A standard curve was drawn with the mass of deuterated ethanol / the mass of normal hexane as the horizontal axis (x) and the peak area of ​​deuterated ethanol / the peak area of ​​normal hexane as the vertical axis (y). The linear correlation equation of deuterated ethanol was established as shown below: y =0.5132x-0.028, linear correlation coefficient R 2 = 0.996.

[0068] The quantitative standard curves of deuterated methanol and deuterated ethanol showed good linearity and were suitable for quantitative analysis.

[0069] (5) Precision test After 6 consecutive injections, the RSDs of the relative peak area ratios of deuterated methanol and deuterated ethanol were 1.2% and 1.5%, respectively, meeting the requirement of RSD ≤ 2%.

[0070] (6) Recovery rate test When a known amount of standard was added to the blank matrix, the recoveries were 98.4% (dMethanol) and 101.2% (dEtOH), respectively, which were within the acceptance range of 95% to 105%.

[0071] The quantitative analysis method of deuterated methanol and deuterated ethanol in this embodiment uses n-hexane as the internal standard, which has good separation effect and linear correlation (R 2 >0.99). This method is simple to operate, highly sensitive, and reproducible, making it suitable for the determination of deuterated compounds in real samples. Furthermore, the HP-1301 column, due to its weak polarity, performs well in retention time control and peak shape optimization.

[0072] Example 4 This embodiment provides a method for quantitatively detecting deuterated methanol and deuterated ethanol, comprising: (1) Instruments and materials (same as in Example 1) (2) Preparation of standard samples Taking sample 5 as an example, the test solution was prepared and divided into five groups, which were respectively recorded as sample 5A, sample 5B, sample 5C, sample 5D, and sample 5E.

[0073] (3) Chromatographic conditions (except for the temperature program, the rest are the same as in Example 1) Heating rate: Sample 5A: Initial temperature 60°C, hold for 5 min; heat to 120°C at 5°C / min, hold for 5 min; heat to 180°C at 10°C / min, hold for 2 min.

[0074] Sample 5B: Initial temperature 30°C, hold for 10 min; heat to 120°C at 5°C / min, hold for 5 min; heat to 180°C at 10°C / min, hold for 2 min.

[0075] Sample 5C: Initial temperature 60°C, hold for 5 min; heat to 120°C at 2°C / min, hold for 1 min; heat to 180°C at 10°C / min, hold for 2 min.

[0076] Sample 5D: Initial temperature 60°C, hold for 5 min; heat to 120°C at 5°C / min, hold for 5 min; heat to 180°C at 5°C / min, hold for 15 min.

[0077] Sample 5E: Initial temperature 60°C, hold for 5 min, increase the temperature to 180°C at 5°C / min, hold for 7 min.

[0078] (4) Experimental results and analysis, as shown in Table 3 Table 3 Peak time and peak shape observation (I)

[0079] Table 3 Comparison of quantitative accuracy (II)

[0080] As shown in Table 3, the temperature program of the present invention can effectively achieve good separation and accurate quantification of the target compounds.

[0081] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for quantitative detection of deuterated methanol and deuterated ethanol, characterized in that: The following steps are involved: The sample to be tested is injected into the gas chromatograph. After being vaporized in the vaporization chamber, the sample is carried into the chromatographic column by the carrier gas. The components in the sample are separated in the chromatographic column and flow out of the chromatographic column into the hydrogen flame ionization detector. The detector identifies and responds to the sample flowing out of the column. The data processing system converts the detector signal into a chromatogram for quantitative analysis. Wherein, the detection conditions of the gas chromatograph include: The detection temperature of the hydrogen flame ionization detector is: 200~250℃; the injection port temperature is: 230~250℃; the air flow rate is 270~330mL / min; the hydrogen flow rate is 27~33mL / min; the column flow rate is 1~2mL / min, and the split ratio is 10:1~100:

1.

2. The method for quantitative detection of deuterated methanol and deuterated ethanol according to claim 1, wherein: The temperature program of the gas chromatograph is set as follows: the initial column temperature is 40-60°C, the holding time is 2-5 minutes, the temperature is increased to 120°C at a rate of 5-10°C / min, the holding time is 2-5 minutes, and then the temperature is increased to 180°C at a rate of 10-20°C / min, and the holding time is 2-12 minutes.

3. The quantitative detection method of deuterated methanol and deuterated ethanol according to claim 1, wherein: The chromatographic column is selected from one of a strong polarity capillary column, a medium polarity capillary column or a weak polarity capillary column.

4. The method for quantitative detection of deuterated methanol and deuterated ethanol according to claim 3, wherein: The model of the capillary column is selected from one of DB-WAX, PoraPLOT U, DB-624, TG-624, OV-624, HP-624, RTX-624, SPB-624, AT-624, ZM-624, BP-624, TR-V1, DB-1301, Rtx-1301, PE-1301, HP-1301, OV-1301 or SPB-1301.

5. The quantitative detection method of deuterated methanol and deuterated ethanol according to claim 4, characterized in that: The stationary phase of the capillary column is selected from one of polyethylene glycol, cyanopropylsiloxane, styrene-divinylbenzene, 50% phenyl-50% methylpolysiloxane, 35% phenyl-65% methylpolysiloxane, 5% phenyl-95% methylpolysiloxane or 6% cyanopropylphenyl-94% polydimethylsiloxane.

6. The method for quantitative detection of deuterated methanol and deuterated ethanol according to claim 5, wherein: The stationary phase of the capillary column is selected from one of styrene-divinylbenzene, 5% phenyl-95% methylpolysiloxane or 6% cyanopropylphenyl-94% polydimethylsiloxane.

7. The method for quantitative detection of deuterated methanol and deuterated ethanol according to claim 1, wherein: The analysis method is an internal standard method, and the internal standard is selected from one of tetrahydrofuran and n-hexane.

8. The method for quantitative detection of deuterated methanol and deuterated ethanol according to claim 1, wherein: The detection conditions of the gas chromatograph also include: a septum purge gas flow rate of 3 mL / min, a tail gas flow rate of 25 mL / min, and an injection volume of 1 μL.

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