Qualitative Analysis Method for Glycerol Segments in Polyglycerols and Esters

Abstract

The present invention relates to a qualitative analysis method for glycerol segments in polyglycerols and esters. The method uses p-toluenesulfonic acid acetic anhydride as a chain scission agent. The chain scission agent reacts with a sample containing a polyglycerol segment, a sample containing a polyethylene glycol segment, and a sample containing a polypropylene glycol segment, respectively, to generate sample derivatives of glycerol triacetate, ethylene glycol diacetate, and propylene glycol diacetate, respectively. The chemical structure of the product is then identified by gas chromatography-mass spectrometry, and a GC-MS total ion current (GC-MS) and mass spectrum of the sample derivatives are obtained. The specific type of the sample derivative is determined by comparing the retention time and mass spectrum of the total ion current (GC-MS) chromatogram of an existing commercially available derivative standard with that of the sample derivative. This allows for qualitative detection of whether the sample's polymer hydrophilic segment is polyglycerol and whether it is mixed with polypropylene glycol or polyethylene glycol.

Description

Technical Field

[0001] The present invention relates to the technical field of qualitative analysis methods for glycerol segments, and in particular to a qualitative analysis method for glycerol segments in polyglycerols and esters. Background Art

[0002] Polyglycerol-n (n represents the degree of polymerization, and n is a positive integer greater than 1) is a polymer compound composed of multiple glycerol molecules linked by ether bonds, exhibiting unique molecular structures and properties. Polyglycerol-n fatty acid esters are products of the esterification reaction between polyglycerol and fatty acids. They typically exhibit high purity, good stability, and specific functional properties, such as emulsification, dispersion, and moisturizing. However, polyglycerol and its esters also have very good toxicity data and are widely used in the food, cosmetics, and pharmaceutical industries. These characteristics also lead to complex production processes, including raw material selection, reaction condition control, purification, and separation, resulting in relatively high production costs. In contrast, polypropylene glycol (PPG) and polyethylene glycol (PEG) are polymer compounds derived from propylene glycol or ethylene glycol through polymerization reactions. Their production processes are relatively simple, and their raw materials can be sourced from a wide range of sources, such as petroleum byproducts. Furthermore, due to intense market competition, the production scale of these compounds continues to expand, further reducing costs. Therefore, in some cases, the cost of polypropylene glycol and polyethylene glycol can be significantly lower than that of polyglycerol-n and its fatty acid esters.

[0003] The primary motivation for malicious adulteration of polypropylene glycol and polyethylene glycol is to significantly reduce production costs. Because these compounds may resemble polyglycerol-n and its fatty acid esters in appearance and offer some substitutability in certain performance aspects, adulteration can significantly reduce raw material costs while maintaining the product's appearance and basic performance. However, infrared spectroscopy alone is not sufficient for identification due to the overlap in functional groups between polyglycerol and its fatty acid esters, polypropylene glycol and its fatty acid esters, and polyethylene glycol and its fatty acid esters. Currently, no commercially available qualitative analysis method can determine whether polyglycerol and its fatty acid esters contain polypropylene glycol or polyethylene glycol. Summary of the Invention

[0004] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a qualitative analysis method for glycerol segments in polyglycerols and esters, which can identify whether the sample is doped with ethylene glycol segments and propylene glycol segments.

[0005] To achieve the above object, the technical solution adopted by the present invention is:

[0006] In a first aspect, the present invention provides a method for qualitative analysis of glycerol segments in polyglycerol and esters, comprising the following steps:

[0007] S1. Reacting p-toluenesulfonic acid and acetic anhydride at 100-130° C. for 40-60 min to obtain p-toluenesulfonic acid acetic anhydride, which is a bond-breaking agent; wherein the mass ratio of p-toluenesulfonic acid to acetic anhydride is 1:(1-1.5);

[0008] S2. Mix the bond-breaking agent with the sample, react at 130-160° C. for 40-60 minutes to obtain a sample derivative, cool, adjust the pH to 7-9, add n-heptane to extract the alcohol acetate, shake well and centrifuge, take the upper extract, put it into a gas chromatography-mass spectrometer for analysis, and obtain a GC-MS total ion current diagram and mass spectrum of the sample derivative. By comparing the retention time in the total ion current chromatogram of the sample derivative with that of the alcohol acetate standard, determine whether the sample derivative is one or more of triacetin, ethylene glycol diacetate, and propylene glycol diacetate, and obtain a detection result of whether the sample contains one or more of glycerol segments, ethylene glycol segments, and propylene glycol segments; wherein the mass ratio of the sample to the bond-breaking agent is 1:(1.5-5).

[0009] The present invention first reacts p-toluenesulfonic acid with excess acetic anhydride to generate p-toluenesulfonic acid acetic anhydride, which is a bond-breaking agent, specifically shown in formula (I):

[0010]

[0011] The sample is then reacted with a bond-breaking agent to obtain a sample derivative of an alcohol acetate, as follows:

[0012] If the sample is polyglycerol-n and / or polyglycerol-n fatty acid ester (n is the degree of polymerization, n is a positive integer greater than 1), it will generate glycerol triacetate during the reaction with the chain scission agent, as shown in formula (II);

[0013]

[0014] If the sample is polypropylene glycol and / or polypropylene glycol fatty acid ester (n is the degree of polymerization, n is a positive integer greater than 1), it will generate propylene glycol diacetate during the reaction with the chain scissor, as shown in formula (III):

[0015]

[0016] If the sample is polyethylene glycol and / or polyethylene glycol fatty acid ester (n is the degree of polymerization, n is a positive integer greater than 1), it will react with the chain scissor to form ethylene glycol diacetate, as shown in formula (IV):

[0017]

[0018] The chemical structure of the product is then identified by gas chromatography-mass spectrometry (GC-MS) to obtain a GC-MS total ion current (TCC) and mass spectrum of the sample derivative. By comparing the retention time in the TIC chromatogram of the sample derivative with that of an alcohol acetate standard, it is determined whether the sample derivative is one or more of triacetin, ethylene glycol diacetate, and propylene glycol diacetate. After comparison, if it is determined that the sample derivative is glycerol triacetate, it means that the polymer hydrophilic segment contained in the sample is glycerol, that is, the sample is polyglycerol-n and / or polyglycerol-n fatty acid ester; if it is determined that the sample derivative is ethylene glycol diacetate, it means that the polymer hydrophilic segment contained in the sample is ethylene glycol, that is, the sample contains polyethylene glycol and / or polyethylene glycol fatty acid ester, indicating that adulteration exists; if it is determined that the sample derivative is propylene glycol diacetate, it means that the polymer hydrophilic segment contained in the sample is propylene glycol, that is, the sample contains polypropylene glycol and / or polypropylene glycol fatty acid ester, indicating that adulteration exists. The present invention can determine whether commercially available samples claiming to be polyglycerol-n and / or polyglycerol-n fatty acid esters are mixed with polypropylene glycol or polyethylene glycol through the above steps, which serves as a qualitative detection role.

[0019] It should be noted that the temperature in step S2 is set to 130-160°C because the reaction cannot proceed if the temperature is below 130°C, and if the temperature is above 160°C, the p-toluenesulfonic acid acetic anhydride will volatilize, thereby affecting the reaction. In addition, because the chain scission agent prepared by the present invention may contain an excess of acetic anhydride, the pH needs to be adjusted to 7-9, preferably pH = 8, after the reaction between the chain scission agent and the sample is completed to remove excess acetic anhydride, which, if not neutralized, will interfere with the test results.

[0020] Preferably, the gas chromatography-mass spectrometry instrument is a detector with an electron ionization source EI(+), the chromatographic column is a quartz capillary column, and the stationary phase is phenylmethylpolysiloxane with a mass concentration of 4-6%.

[0021] Preferably, the gas chromatography parameters are set as follows: the injection port temperature is 220-240°C, the starting temperature of the column box temperature is 110-130°C, maintained for 1-3 minutes, increased to 240-260°C at 8-12°C / min, and maintained for 8-12 minutes; the carrier gas is helium; the injection mode is split injection, and the split ratio is (10-40):1; the column flow rate is 0.8-1.1 mL / min; and the injection volume is 1.0 μL.

[0022] Preferably, the parameters of the mass spectrometer are set as follows: the analyzer is a quadrupole mass analyzer, the ion source is an electron ionization source EI(+), the ionization energy is +70eV, and the temperature of the ion source is 240-260°C; the measurement method is a full scan mode, and the ion mass scanning range is (10-200)m / z.

[0023] Preferably, in step S2, a saturated sodium carbonate aqueous solution is used to adjust the pH to 7-9.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] The present invention adopts p-toluenesulfonic acid acetic anhydride as a chain scission agent. The chain scission agent reacts with a sample containing a polyglycerol chain segment, a sample containing a polyethylene glycol chain segment, and a sample containing a polypropylene glycol chain segment, respectively, to generate sample derivatives of glycerol triacetate, ethylene glycol diacetate, and propylene glycol diacetate, respectively. Then, the chemical structure of the product is identified by gas chromatography-mass spectrometry (GC-MS), and a GC-MS total ion current graph and a mass spectrum of the sample derivative are obtained. By comparing the retention time in the total ion current chromatogram and the mass spectrum of a standard product of the currently available commercial derivative with that of the sample derivative, the specific type of the sample derivative is determined, thereby determining whether the polymer hydrophilic chain segment of the sample is polyglycerol and whether polypropylene glycol or polyethylene glycol is mixed therein, thereby performing a qualitative detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is the total ion current chromatogram of triacetin standard;

[0027] Figure 2 This is the total ion current chromatogram of propylene glycol diacetate standard;

[0028] Figure 3 This is the total ion current chromatogram of ethylene glycol diacetate standard;

[0029] Figure 4 is the standard mass spectrum of triacetin;

[0030] Figure 5 is the standard mass spectrum of propylene glycol diacetate;

[0031] Figure 6 is the standard mass spectrum of ethylene glycol diacetate;

[0032] Figure 7 is a total ion current chromatogram of the sample derivative of Example 1;

[0033] Figure 8 is the mass spectrum of the sample derivative of Example 1;

[0034] Figure 9 is a total ion current chromatogram of the sample derivative of Example 2;

[0035] Figure 10 is the mass spectrum of the sample derivative of Example 2;

[0036] Figure 11is the total ion current chromatogram of the sample derivative of Example 3;

[0037] Figure 12 is the standard mass spectrum of the sample derivative of Example 3;

[0038] Figure 13 is a total ion current chromatogram of the sample derivative of Example 4;

[0039] Figure 14 is the mass spectrum of the sample derivative of Example 4;

[0040] Figure 15 is a total ion current chromatogram of the sample derivative of Example 5;

[0041] Figure 16 This is the infrared spectrum of polyglycerol-10 in Comparative Example 1;

[0042] Figure 17 This is the infrared spectrum of polyglycerol-2 triisostearate in Comparative Example 2;

[0043] Figure 18 This is the infrared spectrum of polypropylene glycol-400 in Comparative Example 3;

[0044] Figure 19 This is the infrared spectrum of polyethylene glycol-600 in Comparative Example 4;

[0045] Figure 20 This is the total ion current chromatogram of the sample derivative in Comparative Example 5. DETAILED DESCRIPTION

[0046] In order to better illustrate the purpose, technical solutions and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0047] The sources of the reagents used in the following examples and comparative examples are as follows:

[0048] p-Toluenesulfonic acid: manufacturer: Guangdong Wengjiang Chemical Reagent Co., Ltd., model number: PA05704, purity: AR;

[0049] Acetic anhydride: manufacturer is Shaoguan Gaokexiang High-tech Materials Co., Ltd., model number is G800288, purity is AR;

[0050] n-Heptane: Manufacturer: Guangdong Wengjiang Chemical Reagent Co., Ltd., model: WB00103, purity: AR;

[0051] Polyglycerol-10: Manufacturer: Guangdong Wengjiang Chemical Reagent Co., Ltd., model: PB09189, purity: AR;

[0052] Polyglycerol-10 triisostearate: manufacturer: Hubei Xinkang Pharmaceutical Chemical Co., Ltd., model number: XK8630;

[0053] Polypropylene glycol-400: manufacturer is Jiangsu Dena Chemical Co., Ltd., model number is PPG-400, hydroxyl value is 255-312 mgKOH / g, number average molecular weight is 360-440;

[0054] Polyethylene glycol-600: The manufacturer is Shanghai Bangao Chemical Co., Ltd., the model is PEG-600, the hydroxyl value is 170-208 mgKOH / g, and the number average molecular weight is 540-660;

[0055] Polyglyceryl-10 laurate: Manufacturer: Shanghai Dingfen Chemical Technology Co., Ltd., model number P33115.

[0056] Unless otherwise specified, other materials and reagents used in the examples can be obtained from commercial sources.

[0057] Example 1

[0058] The qualitative analysis method of glycerol segments in polyglycerol and esters comprises the following steps:

[0059] S1. Use an electronic balance to weigh about 0.4 g of p-toluenesulfonic acid and 0.6 g of acetic anhydride in a headspace bottle, seal it with a lid, shake well, and heat it in a 120°C constant temperature forced air drying oven for 1 hour. After cooling, protect it from light and set aside to obtain p-toluenesulfonic acid acetic anhydride, which is the bond scission agent.

[0060] S2. Add 0.15 g of polyglycerol-10 sample to the headspace bottle with the bond-breaking agent in step S1, place it in a constant temperature forced air drying oven at 140°C for heating reaction for 1 hour, shake it several times during the constant temperature process to make it uniform, cool it to room temperature to obtain a sample derivative solution, use saturated sodium carbonate aqueous solution to neutralize the sample derivative solution to a pH of 8, add 10 mL of n-heptane to extract the sample derivative, shake it evenly and centrifuge it, take the upper layer of extract and set it aside for analysis by gas chromatography-mass spectrometry (GC-MS).

[0061] The specific GC-MS conditions are as follows:

[0062] Use the instrument

[0063] Gas chromatography-mass spectrometry: with electron ionization source EI (+) detector; chromatographic column: quartz capillary column, weak polarity, the stationary phase is 5% phenylmethylpolysiloxane, the reference model is DB-5MS 30m (column length) × 0.25mm (inner diameter) × 0.25μm (stationary phase film thickness).

[0064] Gas chromatography conditions

[0065] The injection port temperature was 230°C, the column oven temperature started at 120°C, maintained for 2 min, then increased to 250°C at 10°C / min and maintained for 10 min; the carrier gas was helium (purity ≥99.999%); the injection method was split injection with a split ratio of 40:1; column flow rate: 1.0 mL / min, and injection volume: 1.0 μL.

[0066] Mass spectrometry conditions

[0067] The analyzer is a quadrupole mass analyzer; the ion source is an electron ionization source EI(+), the ionization energy is +70eV, and the ion source temperature is 250°C; the measurement method is a full scan mode, and the ion mass scanning range is (10-200)m / z.

[0068] The total ion current chromatogram of the sample derivative is as follows Figure 7 As shown, the retention time of the sample derivative is 5.696 min, which is consistent with Figure 1 The retention time of the total ion chromatogram of the triacetin standard is consistent with that of the standard. The mass spectrum of the sample derivative is shown in Figure 8 As shown, it is Figure 4 The triacetin shown is the same, so it is verified that the sample contains polyglycerol segments and does not contain other monomers, which is consistent with the characteristics of the actually added polyglycerol-10.

[0069] Example 2

[0070] The qualitative analysis method of glycerol segments in polyglycerol and esters comprises the following steps:

[0071] S1. Use an electronic balance to weigh about 0.5 g of p-toluenesulfonic acid and 0.5 g of acetic anhydride in a headspace bottle, seal it with a lid, shake well, and heat it in a constant temperature forced air drying oven at 100°C for 1 hour. After cooling, protect it from light and set aside to obtain p-toluenesulfonic acid acetic anhydride, which is the bond-breaking agent.

[0072] S2. Add 0.15 g of polyglycerol-10 triisostearate sample to the headspace bottle with the bond-breaking agent in step S1, place it in a constant temperature forced air drying oven at 130°C and heat it for reaction for 1 hour. Shake it several times during the constant temperature process to make it uniform, cool it to room temperature, and obtain a sample derivative solution. Use saturated sodium carbonate aqueous solution to neutralize the sample derivative solution to a pH of 8. Add 10 mL of n-heptane to extract the alcohol acetate, shake it well, and centrifuge it for separation. Take the upper layer of extract and set it aside for analysis by gas chromatography-mass spectrometry (GC-MS).

[0073] The specific GC-MS conditions are as follows:

[0074] Use the instrument

[0075] Gas chromatography-mass spectrometry: with electron ionization source EI (+) detector; chromatographic column: quartz capillary column, weak polarity, the stationary phase is 4% phenylmethylpolysiloxane, the reference model is DB-5MS 30m (column length) × 0.25mm (inner diameter) × 0.25μm (stationary phase film thickness).

[0076] Gas chromatography conditions

[0077] The injection port temperature was 220°C, the column oven temperature started at 110°C, maintained for 3 min, then increased to 240°C at 8°C / min and maintained for 12 min; the carrier gas was helium (purity ≥99.999%); the injection method was split injection with a split ratio of 10:1; column flow rate: 0.8 mL / min, and injection volume: 1.0 μL.

[0078] Mass spectrometry conditions

[0079] The analyzer is a quadrupole mass analyzer; the ion source is an electron ionization source EI(+), the ionization energy is +70eV, and the ion source temperature is 240°C; the measurement method is a full scan mode, and the ion mass scanning range is (10-200)m / z.

[0080] The total ion current chromatogram of the sample derivative is as follows Figure 9 As shown, the retention time of the sample derivative is 5.688 min, which is consistent with Figure 1 The retention time of the total ion chromatogram of the triacetin standard is consistent with that of the standard. The mass spectrum of the sample derivative is shown in Figure 10 As shown, it is Figure 4 The triacetin shown is the same as that of the glycerol triacetate, so it is verified that the sample contains polyglycerol segments, which is consistent with the characteristics of the actually added polyglyceryl-10 triisostearate.

[0081] Example 3

[0082] The qualitative analysis method of glycerol segments in polyglycerol and esters comprises the following steps:

[0083] S1. Use an electronic balance to weigh about 0.4 g of p-toluenesulfonic acid and 0.6 g of acetic anhydride in a headspace bottle, seal it with a lid, shake well, and heat it in a 130°C constant temperature forced air drying oven for 40 minutes. After cooling, protect it from light and set aside to obtain p-toluenesulfonic acid acetic anhydride, which is the bond scission agent.

[0084] S2. Add 0.10 g of polypropylene glycol-400 sample to the headspace bottle with the bond-breaking agent in step S1, place it in a constant temperature forced air drying oven at 160°C and heat it for reaction for 1 hour. Shake it several times during the constant temperature process to make it uniform, cool it to room temperature, and obtain a sample derivative solution. Use saturated sodium carbonate aqueous solution to neutralize the sample derivative solution to a pH of 7. Add 10 mL of n-heptane to extract the alcohol acetate, shake it well, and centrifuge it for separation. Take the upper layer of extract and set it aside for analysis by gas chromatography-mass spectrometry (GC-MS).

[0085] The specific GC-MS instrument conditions are as follows:

[0086] Use the instrument

[0087] Gas chromatography-mass spectrometry: with electron ionization source EI (+) detector; chromatographic column: quartz capillary column, weak polarity, stationary phase is 6% phenylmethylpolysiloxane, reference model is DB-5MS 30m (column length) × 0.25mm (inner diameter) × 0.25μm (stationary phase film thickness).

[0088] Gas chromatography conditions

[0089] The injection port temperature was 240°C, the column oven temperature started at 130°C, maintained for 1 min, then increased to 260°C at 12°C / min and maintained for 8 min; the carrier gas was helium (purity ≥99.999%); the injection method was split injection with a split ratio of (40:1); column flow rate: 1.1 mL / min, injection volume: 1.0 μL.

[0090] Mass spectrometry conditions

[0091] The analyzer is a quadrupole mass analyzer; the ion source is an electron ionization source EI(+), the ionization energy is +70eV, and the ion source temperature is 260°C; the measurement method is a full scan mode, and the ion mass scanning range is (10-200)m / z.

[0092] The total ion current chromatogram of the sample derivative is as follows Figure 11 As shown, the retention time of the sample derivative is 2.06 min, which is consistent with Figure 2 The retention time of the total ion chromatogram of the propylene glycol diacetate standard is consistent with that of the standard. The mass spectrum of the sample derivative is shown in FIG. Figure 12 As shown, it is Figure 5 The propylene glycol diacetate shown is the same, so it is verified that the sample contains propylene glycol segments, which is consistent with the characteristics of the actually added polypropylene glycol-400.

[0093] Example 4

[0094] The qualitative analysis method of glycerol segments in polyglycerol and esters comprises the following steps:

[0095] S1. Use an electronic balance to weigh about 0.4 g of p-toluenesulfonic acid and 0.6 g of acetic anhydride in a headspace bottle, seal it with a lid, shake well, and heat it in a 120°C constant temperature forced air drying oven for 1 hour. After cooling, protect it from light and set aside to obtain p-toluenesulfonic acid acetic anhydride, which is the bond scission agent.

[0096] S2. Add 0.15 g of polyethylene glycol-600 sample to the headspace bottle with the bond-breaking agent in step S1, place it in a constant temperature forced air drying oven at 140°C and heat it for reaction for 1 hour. Shake it several times during the constant temperature process to make it uniform, cool it to room temperature, and obtain a sample derivative solution. Use saturated sodium carbonate aqueous solution to neutralize the sample derivative solution to pH = 9, add 10 mL of n-heptane to extract alcohol acetate, shake it well, and centrifuge it for separation. Take the upper layer of extract and set it aside for analysis by gas chromatography-mass spectrometry (GC-MS).

[0097] The specific GC-MS conditions are as follows:

[0098] Use the instrument

[0099] Gas chromatography-mass spectrometry: with electron ionization source EI (+) detector; chromatographic column: quartz capillary column, weak polarity, the stationary phase is 5% phenylmethylpolysiloxane, the reference model is DB-5MS 30m (column length) × 0.25mm (inner diameter) × 0.25μm (stationary phase film thickness).

[0100] Gas chromatography conditions

[0101] The injection port temperature was 230°C, the column oven temperature started at 120°C, maintained for 2 min, then increased to 250°C at 10°C / min and maintained for 10 min; the carrier gas was helium (purity ≥99.999%); the injection method was split injection with a split ratio of (40:1); column flow rate: 1.0 mL / min, injection volume: 1.0 μL.

[0102] Mass spectrometry conditions

[0103] The analyzer is a quadrupole mass analyzer; the ion source is an electron ionization source EI(+), the ionization energy is +70eV, and the ion source temperature is 250°C; the measurement method is a full scan mode, and the ion mass scanning range is (10-200)m / z.

[0104] The total ion current chromatogram of the sample derivative is as follows Figure 13 As shown, the retention time of the sample derivative is 1.92 min, which is consistent with Figure 3 The retention time of the total ion chromatogram of the ethylene glycol diacetate standard is consistent with that of the standard. The mass spectrum of the sample derivative is shown in FIG. Figure 14 As shown, it is Figure 6The ethylene glycol diacetate shown is the same, so it is verified that the sample contains ethylene glycol segments, which is consistent with the characteristics of the actually added polyethylene glycol-600.

[0105] Example 5

[0106] The qualitative analysis method of glycerol segments in polyglycerol and esters comprises the following steps:

[0107] S1. Use an electronic balance to weigh about 0.4 g of p-toluenesulfonic acid and 0.6 g of acetic anhydride in a headspace bottle, seal it with a lid, shake well, and heat it in a 120°C constant temperature forced air drying oven for 1 hour. After cooling, protect it from light and set aside to obtain p-toluenesulfonic acid acetic anhydride, which is the bond scission agent.

[0108] S2. Add 0.15 g of polyglycerol-10 laurate sample to the headspace bottle with the bond-breaking agent in step S1, place it in a constant temperature forced air drying oven at 140°C for heating reaction for 1 hour, shake it several times during the constant temperature process to make it uniform, cool it to room temperature to obtain a sample derivative solution, use saturated sodium carbonate aqueous solution to neutralize the sample derivative solution to a pH of 8, add 10 mL of n-heptane to extract the sample derivative, shake it evenly, and centrifuge it, take the upper layer of extract and set it aside for analysis by gas chromatography-mass spectrometry (GC-MS).

[0109] The specific GC-MS conditions are as follows:

[0110] Use the instrument

[0111] Gas chromatography-mass spectrometry: with electron ionization source EI (+) detector; chromatographic column: quartz capillary column, weak polarity, the stationary phase is 5% phenylmethylpolysiloxane, the reference model is DB-5MS 30m (column length) × 0.25mm (inner diameter) × 0.25μm (stationary phase film thickness).

[0112] Gas chromatography conditions

[0113] The injection port temperature was 230°C, the column oven temperature started at 120°C, maintained for 2 min, then increased to 250°C at 10°C / min and maintained for 10 min; the carrier gas was helium (purity ≥99.999%); the injection method was split injection with a split ratio of (40:1); column flow rate: 1.0 mL / min, injection volume: 1.0 μL.

[0114] Mass spectrometry conditions

[0115] The analyzer is a quadrupole mass analyzer; the ion source is an electron ionization source EI(+), the ionization energy is +70eV, and the ion source temperature is 250°C; the measurement method is a full scan mode, and the ion mass scanning range is (10-200)m / z.

[0116] The total ion current chromatogram of the sample derivative is as follows Figure 15 As shown, the retention time of the sample derivative is 5.679 min, which is consistent with Figure 1 The retention time in the total ion chromatogram of the triacetin standard is consistent, thus verifying that the sample contains polyglycerol segments, which is consistent with the characteristics of the actual added polyglyceryl-10 laurate.

[0117] Comparative Example 1

[0118] The polyglycerol-10 sample was subjected to infrared spectroscopy analysis. Figure 16 : Absorption peak 3333cm -1 The hydroxyl -OH vibration peak is 2925 cm -1 and 2873cm -1 -CH2- vibration peak, 1456cm -1 -CH2- vibration peak, 1317cm -1 -CH- vibration peak, 1040cm -1 Because polyglycerol, polyethylene glycol, and polypropylene glycol all contain the above functional groups, it is impossible to identify whether they contain polyglycerol segments through infrared spectroscopy analysis.

[0119] Comparative Example 2

[0120] The polyglyceryl-2 triisostearate sample was subjected to infrared spectroscopy analysis. Figure 17 : 2923cm -1 and 2854cm -1 -CH2- vibration peak, 1742cm -1 -COOR vibration peak, 1458cm -1 The -CH2- vibration peak is very weak, so the infrared spectrum cannot identify whether it contains polyglycerol segments.

[0121] Comparative Example 3

[0122] The polypropylene glycol-400 sample was subjected to infrared spectroscopy analysis. Figure 18 :3312cm -1 The hydroxyl -OH vibration peak is 2970 cm -1 -CH3- vibration peak, 2930cm -1 and 2876cm -1 -CH2- vibration peak, 1456cm -1 -CH2- vibration peak, 1375cm -1 -CH- vibration peak, 1038cm -1Because polyglycerol, polyethylene glycol, and polypropylene glycol all contain the above functional groups, it is impossible to identify whether they contain polypropylene glycol segments through infrared spectroscopy analysis.

[0123] Comparative Example 4

[0124] The polyethylene glycol-600 was subjected to infrared spectroscopy analysis. Figure 19 : Absorption peak 3333cm -1 The hydroxyl -OH vibration peak is 2933 cm -1 and 2869cm -1 -CH2- vibration peak, 1456cm -1 -CH2- vibration peak, 1353cm -1 -CH- vibration peak, 1052cm -1 Because polyglycerol, polyethylene glycol, and polypropylene glycol all contain the above functional groups, it is impossible to identify whether they contain polyethylene glycol segments through infrared spectroscopy analysis.

[0125] Comparative Example 5

[0126] The difference between Comparative Example 5 and Example 5 is that the chain scission agent is acetic anhydride in an amount equal to that in Example 5, and the detection method and sample are the same as those in Example 5.

[0127] The total ion current chromatogram of the sample derivative is as follows Figure 20 As shown, the target peak for triacetin is absent, indicating that acetic anhydride is unable to cleave polyglycerol-10 laurate to produce triacetin. Similarly, acetic anhydride is also unable to cleave polyethylene glycol and its esters, or polypropylene glycol and its esters, to produce ethylene glycol diacetate or propylene glycol diacetate. This demonstrates that p-toluenesulfonic acid acetic anhydride can effectively hydrolyze polyglycerol segments, with triacetin being one of the reaction products, demonstrating the reliability of its use in polyglycerol hydrolysis.

[0128] In summary, the present invention uses p-toluenesulfonic acid acetic anhydride as a chain scission agent, which reacts with a sample containing a polyglycerol segment, a sample containing a polyethylene glycol segment, and a sample containing a polypropylene glycol segment, respectively, to generate sample derivatives of glycerol triacetate, ethylene glycol diacetate, and propylene glycol diacetate, respectively. The chemical structure of the product is then identified by gas chromatography-mass spectrometry (GC-MS) to obtain a GC-MS total ion current (TCC) and mass spectrum of the sample derivatives. The specific type of the sample derivative is determined by comparing the retention time and mass spectrum in the TIC chromatogram of the standard and the sample derivative, thereby confirming the polymer hydrophilic segment of the corresponding ester. It is then possible to determine whether the polymer hydrophilic segment of the sample is polyglycerol and whether it is mixed with polypropylene glycol or polyethylene glycol, which serves as a qualitative test.

[0129] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A method for qualitative analysis of glycerol segments in polyglycerol and esters, characterized in that: The following steps are involved: S1. Reacting p-toluenesulfonic acid and acetic anhydride at 100-130° C. for 40-60 min to obtain p-toluenesulfonic acid acetic anhydride, which is a bond-breaking agent; wherein the mass ratio of p-toluenesulfonic acid to acetic anhydride is 1:(1-1.5); S2. Mix the bond scissor of step S1 with the sample, react at 130-160° C. for 40-60 min to obtain a sample derivative, cool, adjust the pH to 7-9, add n-heptane to extract the alcohol acetate, shake well and centrifuge, take the upper extract, put it into gas chromatography-mass spectrometry for analysis, obtain the GC-MS total ion current and mass spectrum of the sample derivative, and judge whether the sample derivative is triacetin, ethylene glycol or the like by comparing the retention time in the total ion current chromatogram of the sample derivative with that of the alcohol acetate standard. One or more of diacetate and propylene glycol diacetate are used to obtain a test result indicating whether the sample contains one or more of glycerol segments, ethylene glycol segments, and propylene glycol segments; wherein the mass ratio of the sample to the bond-breaking agent is 1:(1.5-5); and the gas chromatography conditions are as follows: the chromatographic column is a quartz capillary column, the stationary phase is phenylmethylpolysiloxane with a mass concentration of 4-6%, and the column box temperature starts at 110-130°C, is maintained for 1-3 minutes, is increased at 8-12°C / min to 240-260°C, and is maintained for 8-12 minutes.

2. The qualitative analysis method according to claim 1, wherein The gas chromatography-mass spectrometry instrument is an EI (+) detector with an electron ionization source.

3. The qualitative analysis method according to claim 1, wherein The gas chromatography parameters were set as follows: injection port temperature was 220-240° C., carrier gas was helium; injection mode was split injection, split ratio was (10-40):1; column flow rate was 0.8-1.1 mL / min; injection volume was 1.0 μL.

4. The qualitative analysis method according to claim 1, wherein The mass spectrometer parameters were set as follows: the analyzer was a quadrupole mass analyzer, the ion source was an electron ionization source EI(+), the ionization energy was +70 eV, and the ion source temperature was 240-260°C; the measurement method was full scan mode, and the ion mass scanning range was (10-200) m / z.

5. The qualitative analysis method according to claim 1, wherein In step S2, a saturated sodium carbonate aqueous solution is used to adjust the pH to 7-9.

Images