Qualitative analysis method for glycerol chain segments in polyglycerol and esters

Abstract

The invention relates to a qualitative analysis method for glycerol chain segments in polyglycerol and esters. According to the method, p-toluene sulfonic acid acetic anhydride is adopted 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, and sample derivatives of glycerol triacetate, ethylene glycol diacetate and propylene glycol diacetate are correspondingly generated respectively; then identifying the chemical structure of the product through gas chromatography-mass spectrometry to obtain a GC-MS total ion chromatogram and a mass spectrogram of the sample derivative, and comparing the retention time and the mass spectrogram in the total ion chromatogram of the existing commercially available derivative standard substance and the sample derivative to determine the specific type of the sample derivative. Therefore, whether a polymer hydrophilic chain segment of a sample is polyglycerol or not and whether polypropylene glycol or polyethylene glycol is mixed or not can be determined, and a qualitative detection effect is achieved.

Description

Technical Field

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

[0002] Polyglycerol-n (n is the degree of polymerization, n is a positive integer greater than 1) is a polymer compound formed by connecting multiple glycerol molecules through ether bonds, and has unique molecular structure and properties. Polyglycerol-n fatty acid esters are products obtained by esterification of polyglycerol and fatty acids. They usually have high purity, good stability and specific functional properties, such as emulsification, dispersion, moisturizing, etc. However, polyglycerol and esters also have very good toxicity data and are widely used in food, cosmetics, and pharmaceutical industries. These characteristics also lead to the complexity of their production process, including raw material selection, reaction condition control, purification and separation, so the production cost is relatively high. In contrast, polypropylene glycol (PPG) and polyethylene glycol (PEG) are polymer compounds obtained by polymerization of propylene glycol or ethylene glycol. Their production process is relatively simple, and the raw materials are widely sourced, such as petroleum by-products. In addition, due to fierce market competition, the production scale of these compounds continues to expand and the cost is further reduced. Therefore, in some cases, the cost of polypropylene glycol and polyethylene glycol may be much lower than that of polyglycerol-n and its fatty acid esters.

[0003] The main motivation for malicious adulteration of polypropylene glycol and polyethylene glycol is to significantly reduce production costs. Since these compounds may be similar in appearance to polyglycerol-n and its fatty acid esters and have certain substitutability in certain properties, the cost of raw materials can be greatly reduced by adulteration while maintaining the appearance and basic properties of the product. If infrared spectroscopy is used for identification, it is impossible to use infrared spectroscopy alone for identification because the functional groups of polyglycerol and polyglycerol fatty acid esters, polypropylene glycol and polypropylene glycol fatty acid esters, and polyethylene glycol and polyethylene glycol fatty acid esters overlap. At present, there is no qualitative analysis method on the market that can determine whether polyglycerol and polyglycerol fatty acid ester samples 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 polyglycerol and esters, which can identify whether ethylene glycol segments and propylene glycol segments are mixed in the sample.

[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. React 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 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 a gas chromatograph-mass spectrometer for analysis, and obtain a GC-MS total ion flow diagram and mass spectrum of the sample derivative. By comparing the retention time in the total ion flow chromatogram of the sample derivative and 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 firstly reacts p-toluenesulfonic acid with excess acetic anhydride to generate p-toluenesulfonic acid acetic anhydride, i.e., 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 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, and n is a positive integer greater than 1), it will generate ethylene glycol diacetate during the reaction with the chain scissor, as shown in formula (IV):

[0017]

[0018] Then, the chemical structure of the product is identified by gas chromatography-mass spectrometry (GC-MS) to obtain the GC-MS total ion flow diagram and mass spectrum of the sample derivative. By comparing the retention time in the total ion flow chromatogram of the sample derivative with that of the 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 triacetin, 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 the presence of adulteration; 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 the presence of adulteration. The present invention can determine whether the 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 plays a role in qualitative detection.

[0019] It should be noted that the reason for setting the temperature to 130-160° C. in step S2 is that if the temperature is lower than 130° C., the reaction cannot proceed, and if the temperature is higher than 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 has 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, in order to remove excess acetic anhydride, which will interfere with the test results if it is not neutralized.

[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 parameters of the gas chromatography 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 min, increased to 240-260°C at 8-12°C / min, and maintained for 8-12 min; 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; 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 invention adopts p-toluenesulfonic acetic anhydride as a chain scission agent, and 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, and generates 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 the GC-MS total ion flow diagram and mass spectrum diagram of the sample derivative are obtained. By comparing the retention time in the total ion flow chromatogram and the mass spectrum diagram of the standard product of the currently available commercial derivative with the sample derivative, the specific type of the sample derivative is determined, so as to determine whether the polymer hydrophilic chain segment of the sample is polyglycerol and whether it is mixed with polypropylene glycol or polyethylene glycol, which plays a role of qualitative detection. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

[0028] Figure 3 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 the 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] Fig. 9 is the total ion current chromatogram of the sample derivative of Example 2;

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

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

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

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

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

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

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

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

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

[0044] Fig.19 It is the infrared spectrum of polyethylene glycol-600 in comparative example 4;

[0045] Fig. 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 is Guangdong Wengjiang Chemical Reagent Co., Ltd., model number is PA05704, purity is AR;

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

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

[0051] Polyglycerol-10: The manufacturer is Guangdong Wengjiang Chemical Reagent Co., Ltd., the model is PB09189, and the purity is AR;

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

[0053] Polypropylene glycol-400: The manufacturer is Jiangsu Dena Chemical Co., Ltd., the model is PPG-400, the hydroxyl value is 255-312 mgKOH / g, and the 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: The manufacturer is Shanghai Dingfen Chemical Technology Co., Ltd., model number is P33115.

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

[0057] Example 1

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

[0059] S1. Use an electronic balance to weigh about 0.4g of p-toluenesulfonic acid and 0.6g of acetic anhydride in a headspace bottle, cover and seal, shake well and place in a 120℃ constant temperature forced air drying oven to heat for 1h. After cooling, keep away from light for later use to obtain p-toluenesulfonic acid acetic anhydride, which is the bond scissor.

[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 well and separate it by centrifuge, 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 starting temperature of the column box was 120°C, maintained for 2 min, 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.

[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 +70 eV, and the temperature of the ion source 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 shown in Figure 7 As shown, the retention time of the sample derivative is 5.696min, which is consistent with Figure 1 The retention time is consistent with the total ion current chromatogram of the triacetin standard shown in Figure 1. The mass spectrum of the sample derivative is shown in Figure 2. Figure 8 As shown, it is Figure 4 The triacetin is the same as shown, 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 the glycerol segments in polyglycerol and esters comprises the following steps:

[0071] S1. Use an electronic balance to weigh about 0.5g of p-toluenesulfonic acid and 0.5g of acetic anhydride in a headspace bottle, cover and seal, shake well and place in a 100℃ constant temperature forced air drying oven to heat for 1h. After cooling, keep away from light for later use to obtain p-toluenesulfonic acid acetic anhydride, which is the bond scission 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 for heating 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 alcohol acetate, shake it well, and separate it by centrifugation, 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 starting temperature of the column box was 110°C, maintained for 3 min, 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, 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 +70 eV, and the temperature of the ion source 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 shown in Fig. 9 As shown, the retention time of the sample derivative is 5.688min, which is consistent with Figure 1 The retention time is consistent with the total ion current chromatogram of the triacetin standard shown in Figure 1. The mass spectrum of the sample derivative is shown in Figure 2. Fig.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 the glycerol segments in polyglycerol and esters comprises the following steps:

[0083] S1. Use an electronic balance to weigh about 0.4g of p-toluenesulfonic acid and 0.6g of acetic anhydride in a headspace bottle, cover and seal, shake well and place in a 130℃ constant temperature forced air drying oven to heat for 40min, cool and keep away from light for later use, to obtain p-toluenesulfonic acid acetic anhydride, which is the bond scissor.

[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 for heating 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 alcohol acetate, shake it well, and separate it by centrifugation, 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, the stationary phase is 6% phenylmethylpolysiloxane, the 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 starting temperature of the column box was 130°C, maintained for 1 min, 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, and the split ratio was (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 +70 eV, and the temperature of the ion source 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 shown in Fig.11 As shown, the retention time of the sample derivative is 2.06min, which is consistent with Figure 2 The retention time is consistent with the total ion current chromatogram of the propylene glycol diacetate standard shown in Figure 1. The mass spectrum of the sample derivative is shown in Figure 2. Fig.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 the glycerol segments in polyglycerol and esters comprises the following steps:

[0095] S1. Use an electronic balance to weigh about 0.4g of p-toluenesulfonic acid and 0.6g of acetic anhydride in a headspace bottle, cover and seal, shake well and place in a 120℃ constant temperature forced air drying oven to heat for 1h. After cooling, keep away from light for later use to obtain p-toluenesulfonic acid acetic anhydride, which is the bond scissor.

[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 for heating 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 separate it by centrifugation, 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 starting temperature of the column box was 120°C, maintained for 2 min, 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, and the split ratio was (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 +70 eV, and the temperature of the ion source 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 shown in Fig.13 As shown, the retention time of the sample derivative is 1.92min, which is consistent with Figure 3 The retention time is consistent with the total ion current chromatogram of the ethylene glycol diacetate standard shown in the figure. The mass spectrum of the sample derivative is shown in Fig.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 the glycerol segments in polyglycerol and esters comprises the following steps:

[0107] S1. Use an electronic balance to weigh about 0.4g of p-toluenesulfonic acid and 0.6g of acetic anhydride in a headspace bottle, cover and seal, shake well and place in a 120℃ constant temperature forced air drying oven to heat for 1h. After cooling, keep away from light for later use to obtain p-toluenesulfonic acid acetic anhydride, which is the bond scissor.

[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, 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 sample derivative, shake it well, and centrifuge it in a centrifuge, take the upper layer of the 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 starting temperature of the column box was 120°C, maintained for 2 min, 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, and the split ratio was (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 +70 eV, and the temperature of the ion source 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 shown in Fig.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 current chromatogram of the triacetin standard is consistent, so it is verified that the sample contains polyglycerol segments, which is consistent with the characteristics of the actually added polyglyceryl-10 laurate.

[0117] Comparative Example 1

[0118] The polyglycerol-10 sample was subjected to infrared spectroscopy analysis. Fig.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 polyglycerol-2 triisostearate sample was subjected to infrared spectroscopy analysis. Fig.17 :2923cm -1 and 2854cm -1 -CH2- vibration peak, 1742cm -1 -COOR vibration peak, 1458cm -1 Because the -OH- vibration peak is very weak, 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. Fig.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. Fig.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 its chain scission agent is acetic anhydride in an amount equal to that in Example 5, and its detection method and sample are the same as those in Example 5.

[0127] The total ion current chromatogram of the sample derivative is shown in Fig. 20 As shown, there is no target peak of triacetin, which means that acetic anhydride cannot perform a chain scission reaction on polyglycerol-10 laurate to generate triacetin. Similarly, it can be proved that acetic anhydride cannot perform a chain scission reaction on polyethylene glycol and its esters, polypropylene glycol and its esters to generate ethylene glycol diacetate and propylene glycol diacetate. This proves that using p-toluenesulfonic acetic anhydride as a bond scission agent can effectively hydrolyze polyglycerol segments, and one of the reaction products is triacetin. The bond scission agent is reliable in the hydrolysis of polyglycerol.

[0128] In summary, the present invention adopts p-toluenesulfonic acetic anhydride as a chain scission agent, and 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 triacetin, ethylene glycol diacetate, and propylene glycol diacetate, respectively, and then identifies the chemical structure of the product by gas chromatography-mass spectrometry (GC-MS) coupling method, obtains the GC-MS total ion flow diagram and mass spectrum of the sample derivative, and determines the specific type of the sample derivative by comparing the retention time in the total ion flow chromatogram and the mass spectrum of the standard and the sample derivative, thereby confirming the polymer hydrophilic segment of the corresponding ester, thereby determining whether the polymer hydrophilic segment of the sample is polyglycerol, whether it is mixed with polypropylene glycol or polyethylene glycol, which plays a role in qualitative detection.

[0129] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. A qualitative analysis method for glycerol segments in polyglycerol and esters, characterized in that: The following steps are involved: S1. React 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-breaking agent 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 a gas chromatography-mass spectrometer for analysis, and obtain a GC-MS total ion flow diagram and mass spectrum of the sample derivative. By comparing the retention time in the total ion flow 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).

2. The qualitative analysis method according to claim 1, characterized in that: The gas chromatography-mass spectrometry instrument is an EI (+) detector with an electron ionization source, the chromatographic column is a quartz capillary column, and the stationary phase is phenylmethyl polysiloxane with a mass concentration of 4-6%.

3. The qualitative analysis method according to claim 1, characterized in that: The parameters of the gas chromatography were set as follows: the injection port temperature was 220-240°C, the starting temperature of the column box temperature was 110-130°C, maintained for 1-3 min, increased to 240-260°C at 8-12°C / min, and maintained for 8-12 min; the carrier gas was helium; the injection mode was split injection, and the split ratio was (10-40):1; the column flow rate was 0.8-1.1 mL / min; and the injection volume was 1.0 μL.

4. The qualitative analysis method according to claim 1, characterized in that: 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.

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

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