A method for detecting 16 plasticizers in rosemary leaves by gas chromatography-tandem mass spectrometry

Abstract

The invention discloses a method for detecting 16 plasticizers in rosemary leaves by gas chromatography-tandem mass spectrometry. The method comprises the following steps: taking 16 plasticizer standard stock solutions, preparing mixed standard working solutions with different mass concentrations, respectively carrying out determination under the condition of satisfying certain gas phase conditions, mass spectrometry MS conditions and qualitative and quantitative ion parameters, soaking the rosemary leaf sample in a small amount of water, then extracting with n-hexane, enriching with a Carb-NH3 glass column, eluting with acetonitrile and performing qualitative detection. The whole process of the invention is simple to operate, can achieve a certain degree of enrichment of the plasticizers in the rosemary leaf sample, eliminate possible interference, have high detection sensitivity, and provide reliable results, and can accurately realize the detection of the plasticizers in the rosemary leaves.

Description

Technical Field

[0001] The invention relates to the technical field of plasticizer detection, and specifically to a method for detecting 16 plasticizers in rosemary leaves by using gas chromatography tandem mass spectrometry. Background Art

[0002] Phthalates, also known as phthalic acid esters, are a general term for esters formed by phthalic acid. They are a type of environmental hormone-like substances. Due to mass production and use by humans, they are now widely present in media such as air, water, soil, and food, becoming one of the most widespread environmental pollutants on the earth. These substances can enter the human and animal bodies through breathing, eating, and skin contact, and play a role similar to that of female hormones. They have varying degrees of acute and chronic toxicity, ecotoxicity, teratogenicity, mutagenicity, and other toxicities. Phthalates are lipophilic and difficult to degrade, and can cause harm to humans through enrichment in the food chain;

[0003] Rosemary is a shrub of the dicotyledonous plant class, Lamiaceae family, Rosmarinus genus. It prefers warm climates and is native to Europe and the Mediterranean coast of northern Africa. It was introduced to China as early as the Cao Wei period and is occasionally used in gardens. Antioxidants and rosemary essential oil with excellent antioxidant properties can be extracted from the flowers and leaves of rosemary. Rosemary antioxidants are widely used in the preservation of medicine, fried foods, oil-rich foods and various oils, while rosemary essence is used in spices, air fresheners, ant repellents, and daily chemical industries such as sterilization and insecticide.

[0004] As rosemary is increasingly used in daily life, people are exposed to more and more rosemary. However, the plasticizer content in rosemary is not well tested, which makes it very difficult and inaccurate to use conventional methods to qualitatively and quantitatively measure the plasticizer content in rosemary. Summary of the invention

[0005] The object of the present invention is to provide a method for detecting 16 plasticizers in rosemary leaves by gas chromatography-tandem mass spectrometry to solve the above-mentioned deficiencies in the technology.

[0006] To achieve the above object, the present invention provides the following technical solution: a method for detecting 16 plasticizers in rosemary leaves by gas chromatography tandem mass spectrometry, comprising the following steps:

[0007] (1) Standard working solution configuration of plasticizer

[0008] Step a: 16 plasticizer standard stock solutions were taken to prepare mixed standard working solutions with different mass concentrations, and the mixed standard working solutions were determined by gas chromatography and mass spectrometry (MS) to confirm the mass spectrometry ion fragment peaks;

[0009] (2) Qualitative detection of 16 plasticizers in rosemary leaves

[0010] Step b: weigh 0.5 g of rosemary leaf sample, add 0.3 mL of water to moisten the sample, then add 2 mL of n-hexane, vortex mix for 3 to 5 min, perform ultrasonic extraction for 30 min, then take the upper organic phase, repeat the above steps twice to obtain two organic phases, then combine the two organic phases to obtain a rosemary leaf extract;

[0011] Step c: a glass Carb-NH3 column is mounted on a solid phase extraction device, 5.0 mL of chromatographically pure n-hexane is added for activation, and then the rosemary leaf extract is transferred to the upper end of the solid phase extraction column for extraction and enrichment, wherein the flow rate of the extract is 1 to 2 mL / min;

[0012] Step d: After the extraction and enrichment is completed, 5 mL of chromatographically pure n-hexane is added to elute the column at a flow rate of 1 to 2 mL / min. The n-hexane elution is used to eliminate the interference of the pigment and rosmarinic acid in the rosemary leaves on the detection of plasticizers;

[0013] Step e: Connect a 10.0 mL stoppered graduated tube to the bottom of the small column after being drained, and elute with 5.0 mL of chromatographically pure acetonitrile twice. The filler of the glass Carb-NH3 solid phase extraction column is always kept wet. Collect all the effluent, blow it to complete dryness under nitrogen flow at 40°C, accurately add 1 mL of n-hexane to re-dissolve, and obtain the injection solution for gas chromatography-mass spectrometry detection;

[0014] Step f: Determination of qualitative results of 16 plasticizers in rosemary leaves

[0015] If, during the confirmation of the mass spectrometry ion fragment peaks, the sample solution meets the following conditions at the same time: (i) the retention time of at least one mass chromatographic peak is consistent with that of the mixed standard solution; (ii) the relative abundance corresponding to the chromatographic method is consistent with that of the mixed standard working solution at the same retention time; (iii) the abundance ratio of the two ions detected, the quantitative ion and the qualitative ion, is consistent with that of the mixed standard working solution within the deviation range, then it is determined that the rosemary leaves contain plasticizers;

[0016] If the sample solution satisfies any one or any two of the conditions (i), (ii), (iii) during the confirmation process of the mass spectrometry ion fragment peak, it is determined that the rosemary leaves do not contain plasticizers;

[0017] The retention time deviation is allowed to be ±0.2min, and the relative abundance deviation is ≤20%;

[0018] This qualitative test is used to detect whether the rosemary leaves contain plasticizers. When it is detected that there are no plasticizers in the rosemary leaves, the test is completed. When the rosemary leaves contain plasticizers, go to step (3);

[0019] (3) Quantitative detection of 16 plasticizers in rosemary leaves

[0020] GC-MS quantitative detection, the steps are as follows: take 16 kinds of plasticizer reference substance stock solutions, accurately prepare a series of mixed standard working solutions with different mass concentrations, respectively measure them under the conditions set by the gas chromatograph mass spectrometer, and use the average value Y of the quantitative ion peak area of ​​each substance to perform linear regression on the mass concentration X of the measured component to obtain the regression equation, correlation coefficient and linear range;

[0021] Among them, the concentration corresponding to the signal-to-noise ratio (S / N)>3 is taken as the detection limit, and the concentration corresponding to (S / N)>10 is taken as the quantification limit. The sample is quantified using a linear equation. If the response value of the plasticizer in the sample is within the linear range of the instrument detection, it contains plasticizer, and the linear range is 20-1000 (μg / L).

[0022] As a preferred solution of the present invention, the gas phase conditions are:

[0023] Chromatographic column: VF-1701MS chromatographic column (30m×0.25mm×0.25μm);

[0024] Inlet temperature: 280°C;

[0025] Carrier gas: high-purity helium, purity ≥ 99.999%;

[0026] Capillary column flow rate: 1.00 mL / min;

[0027] Injection method: split injection;

[0028] Split ratio: 10:1;

[0029] Injection volume: 1 μL;

[0030] Quantitative method: external standard method;

[0031] Temperature rising program: 80℃, hold for 0 min, increase to 200℃ at a heating rate of 20℃ / min, hold for 0 min, increase to 220℃ at a heating rate of 10℃ / min, hold for 8.00 min, increase to 240℃ at a heating rate of 5℃ / min, hold for 0 min, increase to 260℃ at a heating rate of 10℃ / min, hold for 3 min, increase to 280℃ at a heating rate of 5℃ / min, hold for 5 min.

[0032] As a preferred solution of the present invention, the mass spectrometry MS conditions are:

[0033] Transmission line temperature: 280°C;

[0034] Ionization method: EI;

[0035] Ion source temperature: 230°C;

[0036] Quadrupole temperature: 130℃;

[0037] Acquisition type: SIM mode.

[0038] As a preferred solution of the present invention, the 16 plasticizer standard stock solutions are respectively dimethyl phthalate standard solution, diethyl phthalate standard solution, diisobutyl phthalate standard solution, dibutyl phthalate standard solution, dimethoxyethyl phthalate standard solution, di-4-methyl-2-pentyl phthalate standard solution, bis-2-ethoxyethyl phthalate standard solution, dipentyl phthalate standard solution, dihexyl phthalate standard solution, butyl benzyl phthalate standard solution, dibutoxyethyl phthalate standard solution, dicyclohexyl phthalate standard solution, di(2-ethylhexyl) phthalate standard solution, diphenyl phthalate standard solution, di-n-octyl phthalate standard solution and dinonyl phthalate standard solution.

[0039] As a preferred embodiment of the present invention, the gradient mass concentrations of the mixed standard working solution prepared in step a are 20 μg / L, 5 g / L, 100 μg / L, 200 μg / L, 500 μg / L and 1000 μg / L, respectively.

[0040] As a preferred solution of the present invention, the rosemary leaves are weighed in step b with an accuracy of 0.1 mg.

[0041] As a preferred scheme of the present invention, a blank group rosemary mixed working solution is also included, and 16 plasticizer standard solutions with a concentration of 0.200 mg / kg are added to the blank group rosemary mixed working solution at a mass ratio of 10:1. The obtained mixed solution is repeatedly measured 6 times, and the recovery rate and precision are calculated to obtain the average value of the recovery rate and the precision.

[0042] Compared with the prior art, the invention has the following beneficial effects: the rosemary leaf sample is first soaked in a small amount of water, then extracted with n-hexane, enriched with a Carb-NH3 glass column, eluted with acetonitrile, and qualitatively detected. The whole process is simple to operate, can achieve a certain degree of enrichment of the plasticizer in the rosemary leaf sample, and eliminate possible interference. The detection sensitivity is high, the result is reliable, and the plasticizer in the rosemary leaf can be accurately detected. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 The following is a table of retention time, quantitative ion and qualitative ion parameters corresponding to various types of plasticizers in this embodiment;

[0044] Figure 2The following is a statistical table of regression equations, correlation coefficients and linear ranges of various types in GC-MS quantitative detection in this embodiment;

[0045] Figure 3 is a mass spectrum diagram showing the relationship between the intensity and retention time of the molecular ion peak of the standard mixed solution in this embodiment;

[0046] Figure 4 This is a statistical table of the recovery rate and relative standard deviation corresponding to the blank group rosemary samples in this embodiment after adding the same concentration of plasticizer standard mixed solution. DETAILED DESCRIPTION

[0047] In order to more clearly explain and illustrate the technical solution and implementation of the present invention, several preferred specific embodiments for implementing the technical solution of the present invention are introduced below.

[0048] The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, and use. It should be understood that in all of these figures, the same or similar figure numbers indicate the same or similar parts and features. The various figures only schematically represent the concepts and principles of the embodiments of the present disclosure, and do not necessarily show the specific dimensions and proportions of the various embodiments of the present disclosure. Specific parts in specific drawings may use exaggerated methods to illustrate the relevant details or structures of the embodiments of the present disclosure. The various publications, patents, and published patent specifications cited herein are incorporated herein by reference in their entirety. The technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention.

[0049] In the description of the present invention, unless otherwise clearly specified and limited, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance; unless otherwise specified or explained, the term "plurality" refers to two or more; the terms "connected" and "fixed" should be understood in a broad sense, for example, "connected" can be a fixed connection or a detachable connection; it can be directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0050] In the description of this specification, it should be understood that the directional words such as "upper", "lower", "left", and "right" described in the embodiments of the present application are described at the angles shown in the accompanying drawings and should not be understood as limitations on the embodiments of the present application. In addition, in the context, it should also be understood that when it is mentioned that an element is connected to another element "upper" or "lower", it can not only be directly connected to another element "upper" or "lower", but also indirectly connected to another element "upper" or "lower" through an intermediate element.

[0051] Example

[0052] Refer to the instruction manual Figure 1-4 The embodiment of the present invention provides a method for detecting 16 plasticizers in rosemary leaves by gas chromatography tandem mass spectrometry, comprising the following steps:

[0053] (1) Standard working solution configuration of plasticizer

[0054] Step a: 16 plasticizer standard stock solutions were taken to prepare mixed standard working solutions with different mass concentrations, and the mixed standard working solutions were determined by gas chromatography and mass spectrometry (MS) to confirm the mass spectrometry ion fragment peaks;

[0055] (2) Qualitative detection of 16 plasticizers in rosemary leaves

[0056] Step b: weigh 0.5 g of rosemary leaf sample, add 0.3 mL of water to moisten the sample, then add 2 mL of n-hexane, vortex mix for 3 to 5 min, perform ultrasonic extraction for 30 min, then take the upper organic phase, repeat the above steps twice to obtain two organic phases, then combine the two organic phases to obtain a rosemary leaf extract;

[0057] Step c: a glass Carb-NH3 column is mounted on a solid phase extraction device, 5.0 mL of chromatographically pure n-hexane is added for activation, and then the rosemary leaf extract is transferred to the upper end of the solid phase extraction column for extraction and enrichment, wherein the flow rate of the extract is 1 to 2 mL / min;

[0058] Step d: After the extraction and enrichment is completed, 5 mL of chromatographically pure n-hexane is added to elute the column at a flow rate of 1 to 2 mL / min. The n-hexane elution is used to eliminate the interference of the pigment and rosmarinic acid in the rosemary leaves on the detection of plasticizers;

[0059] Step e: Connect a 10.0 mL stoppered graduated tube to the bottom of the small column after being drained, and elute with 5.0 mL of chromatographically pure acetonitrile twice. The filler of the glass Carb-NH3 solid phase extraction column is always kept wet. Collect all the effluent, blow it to complete dryness under nitrogen flow at 40°C, accurately add 1 mL of n-hexane to re-dissolve, and obtain the injection solution for gas chromatography-mass spectrometry detection;

[0060] Step f: Determination of qualitative results of 16 plasticizers in rosemary leaves

[0061] If, during the confirmation of the mass spectrometry ion fragment peaks, the sample solution meets the following conditions at the same time: (i) the retention time of at least one mass chromatographic peak is consistent with that of the mixed standard solution; (ii) the relative abundance corresponding to the chromatographic method is consistent with that of the mixed standard working solution at the same retention time; (iii) the abundance ratio of the two ions detected, the quantitative ion and the qualitative ion, is consistent with that of the mixed standard working solution within the deviation range, then it is determined that the rosemary leaves contain plasticizers;

[0062] If the sample solution satisfies any one or any two of the conditions (i), (ii), (iii) during the confirmation process of the mass spectrometry ion fragment peak, it is determined that the rosemary leaves do not contain plasticizers;

[0063] The retention time deviation is allowed to be ±0.2min, and the relative abundance deviation is ≤20%;

[0064] This qualitative test is used to detect whether the rosemary leaves contain plasticizers. When it is detected that there are no plasticizers in the rosemary leaves, the test is completed. When the rosemary leaves contain plasticizers, go to step (3);

[0065] (3) Quantitative detection of 16 plasticizers in rosemary leaves

[0066] GC-MS quantitative detection, the steps are as follows: take 16 kinds of plasticizer reference substance stock solutions, accurately prepare a series of mixed standard working solutions with different mass concentrations, respectively measure them under the conditions set by the gas chromatograph mass spectrometer, and use the average value Y of the quantitative ion peak area of ​​each substance to perform linear regression on the mass concentration X of the measured component to obtain the regression equation, correlation coefficient and linear range;

[0067] The concentration corresponding to the signal-to-noise ratio (S / N)>3 is taken as the detection limit, and the concentration corresponding to (S / N)>10 is taken as the quantification limit. The sample is quantified using a linear equation. If the response value of the plasticizer in the sample is within the linear range of the instrument, the sample contains plasticizer. The linear range is 20-1000 (μg /

[0068] L);

[0069] Quantitative testing can be used to confirm the content of various plasticizers in the raw material rosemary leaves, and to control the content of plasticizers in subsequent extraction products. The specific type of plasticizer can be determined by retention time, quantitative ions, qualitative ions, and abundance ratio. The specific type is one or more of the 16 plasticizers.

[0070] Further, the gas phase conditions are:

[0071] Chromatographic column: VF-1701MS chromatographic column (30m×0.25mm×0.25μm);

[0072] Inlet temperature: 280°C;

[0073] Carrier gas: high-purity helium, purity ≥ 99.999%;

[0074] Capillary column flow rate: 1.00 mL / min;

[0075] Injection method: split injection;

[0076] Split ratio: 10:1;

[0077] Injection volume: 1 μL;

[0078] Quantitative method: external standard method;

[0079] Temperature rising program: 80℃, hold for 0 min, then increase to 200℃ at a heating rate of 20℃ / min, hold for 0 min, increase to 220℃ at a heating rate of 10℃ / min, hold for 8.00 min, then increase to 240℃ at a heating rate of 5℃ / min, hold for 0 min, increase to 260℃ at a heating rate of 10℃ / min, hold for 3 min, then increase to 280℃ at a heating rate of 5℃ / min, hold for 5 min, wherein holding for 0 min means increasing the temperature immediately without maintaining the temperature.

[0080] Furthermore, the mass spectrometry MS conditions are:

[0081] Transmission line temperature: 280°C;

[0082] Ionization method: EI;

[0083] Ion source temperature: 230°C;

[0084] Quadrupole temperature: 130℃;

[0085] Acquisition type: SIM mode.

[0086] Furthermore, the standard stock solutions of 16 plasticizers are dimethyl phthalate standard solution, diethyl phthalate standard solution, diisobutyl phthalate standard solution, dibutyl phthalate standard solution, dimethoxyethyl phthalate standard solution, di-4-methyl-2-pentyl phthalate standard solution, bis-2-ethoxyethyl phthalate standard solution, dipentyl phthalate standard solution, dihexyl phthalate standard solution, butyl benzyl phthalate standard solution, dibutoxyethyl phthalate standard solution, dicyclohexyl phthalate standard solution, di (2-ethylhexyl) phthalate standard solution, diphenyl phthalate standard solution, di-n-octyl phthalate standard solution and dinonyl phthalate standard solution.

[0087] Furthermore, the gradient mass concentrations of the mixed standard working solution prepared in step a are 20 μg / L, 5 g / L, 100 μg / L, 200 μg / L, 500 μg / L and 1000 μg / L, respectively.

[0088] Furthermore, a blank group rosemary mixed working solution is included, and 16 plasticizer standard solutions with a concentration of 0.200 mg / kg are added to the blank group rosemary mixed working solution at a mass ratio of 10:1. The obtained mixed solution is repeatedly measured 6 times, and the recovery rate and precision are calculated to obtain the average value of the recovery rate and precision. The average value result is as follows: Figure 4 shown.

[0089] Furthermore, in step b, the rosemary leaves are weighed to an accuracy of 0.1 mg.

[0090] It should be noted that the above examples are only specific embodiments of the present invention, and the present invention is obviously not limited to the above examples, and there are many similar variations. All variations directly derived or associated from the contents disclosed by the technicians in this field should fall within the protection scope of the present invention.

[0091] The above are only preferred embodiments of the present invention and are not intended to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for detecting 16 plasticizers in rosemary leaves by gas chromatography tandem mass spectrometry, characterized in that: The following steps are involved: (1) Standard working solution configuration of plasticizer Step a: 16 plasticizer standard stock solutions were taken to prepare mixed standard working solutions with different mass concentrations, and the mixed standard working solutions were determined by gas chromatography and mass spectrometry (MS) to confirm the mass spectrometry ion fragment peaks; (2) Qualitative detection of 16 plasticizers in rosemary leaves Step b: weigh 0.5 g of rosemary leaf sample, add 0.3 mL of water to moisten the sample, then add 2 mL of n-hexane, vortex mix for 3 to 5 minutes, perform ultrasonic extraction for 30 minutes, then take the upper organic phase, repeat the above steps twice to obtain two organic phases, and then combine the two organic phases to obtain a rosemary leaf extract; Step c: installing a glass Carb-NH3 column on a solid phase extraction device, adding 5.0 mL of chromatographically pure n-hexane for activation, and then transferring the rosemary leaf extract to the upper end of the solid phase extraction column for extraction and enrichment, wherein the flow rate of the extract is 1-2 mL / min; Step d: After the extraction and enrichment is completed, 5 mL of chromatographically pure n-hexane is added to elute the small column at a flow rate of 1-2 mL / min. The n-hexane elution is used to eliminate the interference of the pigment and rosmarinic acid in the rosemary leaves on the detection of plasticizers; Step e: Connect a 10.0 mL stoppered graduated tube to the bottom of the dried column, and elute with 5.0 mL of chromatographically pure acetonitrile twice. The filler of the glass Carb-NH3 solid phase extraction column is always kept wet. Collect all the effluent, blow it to complete dryness under nitrogen flow at 40°C, accurately add 1 mL of n-hexane to re-dissolve, and obtain the injection solution for gas chromatography-mass spectrometry detection; Step f: Determination of qualitative results of 16 plasticizers in rosemary leaves If, during the confirmation of the mass spectrometry ion fragment peaks, the sample solution meets the following conditions at the same time: (i) the retention time of at least one mass chromatographic peak is consistent with that of the mixed standard solution; (ii) the relative abundance corresponding to the chromatographic method is consistent with that of the mixed standard working solution at the same retention time; (iii) the abundance ratio of the two ions detected, the quantitative ion and the qualitative ion, is consistent with that of the mixed standard working solution within the deviation range, then it is determined that the rosemary leaves contain plasticizers; If the sample solution meets any one or two of the conditions (i), (ii), (iii) during the confirmation of the mass spectrometry ion fragment peak, it is determined that the rosemary leaves do not contain plasticizers; The retention time deviation is allowed to be ±0.2 min, and the relative abundance deviation is ≤20%; This qualitative test is used to detect whether the rosemary leaves contain plasticizers. When it is detected that there are no plasticizers in the rosemary leaves, the test is completed. When the rosemary leaves contain plasticizers, go to step (3). (3) Quantitative detection of 16 plasticizers in rosemary leaves GC-MS quantitative detection, the steps are as follows: take 16 kinds of plasticizer reference substance stock solutions, accurately prepare a series of mixed standard working solutions with different mass concentrations, respectively measure them under the conditions set by the gas chromatograph mass spectrometer, and use the average value Y of the quantitative ion peak area of ​​each substance to perform linear regression on the mass concentration X of the measured component to obtain the regression equation, correlation coefficient and linear range; The concentration corresponding to the signal-to-noise ratio (S / N)>3 is taken as the detection limit, and the concentration corresponding to (S / N)>10 is taken as the quantification limit. The sample is quantified using a linear equation. If the response value of the plasticizer in the sample is within the linear range of the instrument detection, the sample contains plasticizer, and the linear range is 20μg / L-1000μg / L. The gas phase conditions are: Chromatographic column: VF-1701MS chromatographic column specifications: 30 m×0.25 mm×0.25 μm; Inlet temperature: 280°C; Carrier gas: high-purity helium, purity ≥ 99.999%; Capillary column flow rate: 1.00 mL / min; Injection method: split injection; Split ratio: 10:1; Injection volume: 1 μL; Quantitative method: external standard method; Heating program: 80℃, hold for 0 min, increase to 200℃ at a heating rate of 20℃ / min, hold for 0 min, increase to 220℃ at a heating rate of 10℃ / min, hold for 8.00 min, increase to 240℃ at a heating rate of 5℃ / min, hold for 0 min, increase to 260℃ at a heating rate of 10℃ / min, hold for 3 min, increase to 280℃ at a heating rate of 5℃ / min, hold for 5 min; Mass spectrometry MS conditions: Transfer line temperature: 280 °C; Ionization method: EI; Ion source temperature: 230 °C; Quadrupole temperature: 130℃; Acquisition type: SIM mode; The 16 plasticizer standard stock solutions are respectively dimethyl phthalate standard solution, diethyl phthalate standard solution, diisobutyl phthalate standard solution, dibutyl phthalate standard solution, dimethoxyethyl phthalate standard solution, di-4-methyl-2-pentyl phthalate standard solution, bis-2-ethoxyethyl phthalate standard solution, dipentyl phthalate standard solution, dihexyl phthalate standard solution, butyl benzyl phthalate standard solution, dibutoxyethyl phthalate standard solution, dicyclohexyl phthalate standard solution, di (2-ethylhexyl) phthalate standard solution, diphenyl phthalate standard solution, di-n-octyl phthalate standard solution and dinonyl phthalate standard solution.

2. The method according to claim 1, characterized in that: The gradient mass concentrations of the mixed standard working solution prepared in step a are 20 μg / L, 5 g / L, 100 μg / L, 200 μg / L, 500 μg / L and 1000 μg / L, respectively.

3. The method according to claim 1, characterized in that: In step b, weigh the rosemary leaves to the nearest 0.1 mg.

4. The method according to claim 1, characterized in that: The method also includes a blank group rosemary mixed working solution, in which 16 plasticizer standard solutions with a concentration of 0.200 mg / kg are added at a mass ratio of 10:1 to the blank group rosemary mixed working solution, and the obtained mixed solution is repeatedly measured 6 times, and the recovery rate and precision are calculated to obtain the average values ​​of the recovery rate and precision.

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