阅读说明：本技术 一种原位电离技术对中药材中农药有害物质的快速筛查方法 (Method for rapidly screening pesticide harmful substances in traditional Chinese medicines by in-situ ionization technology ) 是由 毛琼丽 李先芝 严玲 刘洋 石豪 钱全全 于 2020-06-18 设计创作，主要内容包括：本发明公开了一种原位电离技术对中药材中农药有害物质的快速筛查方法,包括下述步骤①利用已搭建好的原位电离质谱检测系统对农药标准品等有害物质建立质谱图谱数据库；②利用原位电离源对所检测的样品进行电离；③以质谱系统分别在正负离子扫描模式下进行检测；④将采集的图谱与谱库中的图谱数据进行比对,可对该样品中是否含有农药残留进行快速判断。本发明的检测方法分析速度快,处理过程简便,是具有高通量快速识别有害物质的环境友好型检测方法,检测效率高、使用试剂少,有利于环境保护与职业健康安全。(The invention discloses a method for rapidly screening pesticide harmful substances in traditional Chinese medicines by using an in-situ ionization technology, which comprises the following steps of firstly, establishing a mass spectrogram database for the harmful substances such as pesticide standard substances by using a built in-situ ionization mass spectrum detection system; ionizing the detected sample by using an in-situ ionization source; thirdly, detecting by a mass spectrum system under a positive and negative ion scanning mode respectively; and fourthly, comparing the acquired map with the map data in the library, and rapidly judging whether the sample contains pesticide residues. The detection method has the advantages of high analysis speed, simple and convenient treatment process, high flux, rapid identification of harmful substances, high detection efficiency, less reagent consumption, and contribution to environmental protection and occupational health safety.)

1. A rapid screening method for pesticide harmful substances in traditional Chinese medicines by an in-situ ionization technology is characterized by comprising the following steps:

firstly, a mass spectrogram database is established for the harmful substances of the pesticide by using the established in-situ ionization mass spectrum detection system, and the standard solution of the harmful substances of the pesticide is prepared by using methanol as a solvent.

Secondly, standard solution is dripped on a polytetrafluoroethylene tape, a set in-situ ionization system is used for ionizing the standard substance, and charged ions enter a mass analyzer along with the carrier gas of the sample injector. And collecting ion signals characteristic of the standard substance by using a mass analyzer.

Thirdly, ionizing the detected sample by using an in-situ ionization source.

Detecting by triple quadrupole mass spectrometry in an ion scanning mode respectively;

fifthly, comparing the acquired sample map with standard map data in a library, and rapidly judging whether the sample contains pesticide residues.

2. The method as claimed in claim 1, wherein the pesticidal harmful substances in step (i) include trichlofop, phosphamidon and methylisothiazide.

3. The method according to claim 1, wherein the concentration of the standard solution in step (i) is 1000. mu.g/L.

4. The method of claim 1, wherein in the third step, the sample to be tested is pulverized, 5g of powder is taken, 20mL of methanol is added for ultrasonic dissolution, centrifugation is carried out, supernatant is taken for filtration, the sample solution is placed on a polytetrafluoroethylene tape, a set in-situ ionization system is used for ionization of the standard substance, and a mass analyzer is used for collecting characteristic ion signals of the sample.

5. The method as claimed in claim 1, wherein in the fifth step, the pesticide residue is screened according to the chemical properties of the pesticide standard substance, the ion flow diagram of the sample is compared with the ion flow diagram extracted from the pesticide standard substance in the spectrum library, if the mass spectrum of the sample solution has a characteristic ion peak of a certain pesticide, the pesticide residue is determined to be present in the sample, otherwise, the pesticide residue is determined not to be present.

6. The method as claimed in claim 1, wherein the ionization source of the mass spectrometer is butted in parallel with the sampling taper hole of the mass analyzer, and the ionization intensity is 1.5KV, and the distance is 0.5 cm.

7. The method of claim 1 wherein step (ii) the injector carrier gas is high purity nitrogen at a gas flow rate of 100 mL/min; the discharge gas assists the helium flow rate to be 150mL/min, and the thermal desorption temperature is 180 ℃.

8. The method of claim 1, wherein the ultrasonic frequency in step (c) is 50kHz and 500W, the ultrasonic time is 30 minutes, the rotation speed of the centrifuge is 8000r/min, and the centrifugation time is 5 minutes.

Technical Field

The invention relates to the technical field of traditional Chinese medicine safety analysis, in particular to a rapid screening method for harmful substances of a traditional Chinese medicine.

Background

Most of the traditional Chinese medicinal materials need to be simply decocted and then metabolized and absorbed through the digestive tract or directly enter the body, if harmful chemical substances are contained, the traditional Chinese medicinal materials can cause damage to the human body to different degrees, and the life safety can be seriously threatened. Therefore, the safety of the traditional Chinese medicinal materials is the material basis for ensuring the medication safety and the body health.

In the planting process of traditional Chinese medicinal materials, producers usually take measures of applying pesticides in order to achieve the purposes of preventing plant diseases and insect pests and improving crop yield, but due to abuse or excessive use of the pesticides, the natural ecological environment is polluted, the pesticides can be accumulated through a food chain to harm human bodies, and life safety is threatened. Therefore, the detection and control of pesticide residue in traditional Chinese medicine are especially important.

The in-situ ionization technology can not only perform tests under normal pressure, but also have less strict requirements on environmental conditions and sample preparation than the traditional chromatographic separation technology, and the sample can be detected by simple treatment, and is connected with the mass spectrum in series, so that the in-situ ionization technology has the characteristics of high sensitivity and high accuracy, and the detection timeliness is greatly improved.

Disclosure of Invention

The invention aims to provide a method for rapidly screening harmful substances in traditional Chinese medicines by using an in-situ ionization technology, which has the advantages of high analysis speed, simple and convenient treatment process, high detection efficiency, less reagent consumption and contribution to environmental protection and occupational health safety, and is an environment-friendly detection method for rapidly identifying the harmful substances with high flux.

In order to achieve the above object, the present invention provides the following technical solutions:

a rapid screening method of harmful substances of pesticides in traditional Chinese medicines by an in-situ ionization technology comprises the following steps:

firstly, establishing a mass spectrogram database for the harmful substances of the pesticide by using a built in-situ ionization mass spectrometry detection system, and preparing a standard solution of the harmful substances of the pesticide by using methanol as a solvent;

secondly, standard solution is dripped on a polytetrafluoroethylene tape, a set in-situ ionization system is used for ionizing the standard substance, and charged ions enter a mass analyzer along with the carrier gas of the sample injector. Collecting standard substance characteristic ion signals by using a mass analyzer;

thirdly, ionizing the detected sample by using an in-situ ionization source;

detecting by triple quadrupole mass spectrometry in an ion scanning mode respectively;

fifthly, comparing the acquired sample map with standard map data in a library, and rapidly judging whether the sample contains pesticide residues.

Preferably, the pesticide harmful substances in the step (i) comprise trichlorfon, phosphamidon and methylisothiazide.

Preferably, in step (i), the concentration of the standard solution is 1000. mu.g/L.

Preferably, in the third step, a sample to be detected is crushed, 5g of powder is taken, 20mL of methanol is added for ultrasonic dissolution, centrifugation is carried out, supernatant is taken for filtration, a sample solution is placed on a polytetrafluoroethylene tape, a set in-situ ionization system is used for ionization of a standard substance, and a mass analyzer is used for collecting characteristic ion signals of the sample.

Preferably, in the fifth step, pesticide residue is screened according to chemical properties of pesticide standard substances, the ion flow diagram of the sample is compared with the ion flow diagram extracted from the pesticide standard substances in the spectrum library, if a characteristic ion peak of a certain pesticide appears in the mass spectrogram of the sample solution, the pesticide residue in the sample is judged to be present, otherwise, the pesticide residue is judged not to be present.

Preferably, the ionization source of the mass spectrum and the sampling taper hole of the mass analyzer are butted in parallel without an angle, the distance is 0.5cm, and the ionization intensity is 1.5 KV.

Preferably, the sample injector carrier gas is high-purity nitrogen, and the gas flow rate is 100 mL/min; the discharge gas assists the helium flow rate to be 150mL/min, and the thermal desorption temperature is 180 ℃.

Preferably, the ultrasonic frequency in the third step is 50kHz and 500W, the ultrasonic time is 30 minutes, the rotating speed of the centrifugal machine is 8000r/min, and the centrifugal time is 5 minutes.

Compared with the prior art, the invention has the following effects:

the invention provides a method for rapidly screening pesticide harmful substances in traditional Chinese medicinal materials by using an in-situ ionization technology, which optimizes a traditional pretreatment method and a detection means for pesticide residues in the traditional Chinese medicinal materials, realizes high-flux screening of various pesticide harmful substances in a sample at the same time, has the characteristics of higher sensitivity and specificity and high detection timeliness, uses few reagents at the same time, and is beneficial to environmental protection and occupational health safety.

Drawings

FIG. 1a is an ion spectrum of a carbendazim standard substance;

FIG. 1b is an ion spectrum of a sample of carbendazim;

FIG. 1c is an ion spectrum of a sample for carbendazim spiking;

FIG. 2a is an ion spectrum of an ammonium phosphate standard;

FIG. 2b is an ion spectrum of a sample of ammonium phosphate;

FIG. 2c is an ion spectrum of a ammonium phosphate spiked sample;

FIG. 3a is an ion spectrum of a methylisothiaphos standard substance;

FIG. 3b is an ion spectrum of a methylisothiazide sample;

FIG. 3c is an ion spectrum of a methylisothiazide labeled sample;

FIG. 4 is an ion spectrum of acquired carbendazim;

FIG. 5 is an ion spectrum of collected phosphamines;

FIG. 6 is an ion spectrum of the collected methylisothiafos.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be further described with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.