| Launch：2022-07-04 |
Rich in a variety of nutrients needed by the human body, the fruit is a delicious, delicious and loved food, and it is also one of the daily consumer goods of residents. When you enjoy the delicious food in a leisurely afternoon, have you ever wondered whether these fruits are safe? Whether there is a problem of pesticide residue exceeding the standard.
In the field of agricultural production, some pesticides are often sprayed to control pests and diseases to improve crop yields, although pesticides in the plant body after metabolism will degrade part of the pesticide, but due to the difficulty of degradation of some pesticides themselves, medication cycle and time to market and other factors, pesticides in the plant body can’t be completely degraded, there may still be some pesticide residues on the surface of the plant body or fruit. The detection of pesticide residues in fruits has always been a hot topic of concern, and the current pesticide residue detection methods are mainly as follows:
1) GCMS temperament combination: the test takes a long time, the test cost is high, and the instrument price is expensive;
2) Enzyme inhibition method: the price is cheap, the test time is short, and the high-throughput test can be carried out, but it cannot be accurately characterized, different pesticides can be distinguished, and only organophosphorus and carbamate pesticides can be tested.
For the detection of pesticide residues in fruits, such as Hai Optoelectronics based on surface-enhanced Raman spectroscopy technology combined with the self-developed small Raman spectrometer (RMS1000), a series of pesticide residue rapid detection schemes have been developed. The test time of this method is similar to that of enzyme inhibition rapid detection method, the cost is much lower than that of GCMS, and it can distinguish between pesticides and has a clear qualitative basis.
Raman spectroscopy is a kind of scattering spectrum, can reflect the vibration and rotation information of molecules, the Raman spectrogram of each substance is different, you can distinguish different substances by Raman spectrogram, thereby helping researchers analyze the molecular structure of the substance to be measured and characterize the substance. For example, Raman spectroscopy can be used to distinguish methanol and ethanol simply, quickly and accurately.
Therefore, based on surface-enhanced Raman spectroscopy, based on precious metal gold and silver nanosols combined with independent research and development of Raman spectrometer, pretreatment integrated machine, food safety test software can achieve rapid screening of pesticide residues in agricultural products. Today we use a fast testing protocol such as Hiraman to determine whether these fruits contain a large amount of pesticide residues.
3.1 We bought seasonal fruits such as apples, oranges, bananas, mangoes, pineapples etc from the supermarket.
3.2 Instrument used - RMS1000 micro Raman spectrometer, pre-processing integrated machine RFSC-1000.
Reagents and consumables used:
3.3 Open the Raman speed test kit and follow the instructions in the kit.
3.4 After the sample is extracted, place it in the cuvette (1) and the liquid holder (2) and you can start the test with the RMS1000.
The test results of hypothion and carbendazim in several fruits are as follows:
As can be seen from the figure, the top two are raman spectral lines of sesquiphos and carbendazim standards, and both hypothion and carbendazim have multiple Raman characteristic displacements. The characteristic peak spectrum of these two pesticides was not found in the test maps of apples, bananas, mangoes and pineapples purchased in supermarkets.
To further verify our test results, we performed a lower level of addition experiment (LOD) on apples and pineapples, adding 0.5 ppm carbendazim and hypothion to apples and pineapples, respectively, as shown in the figure below.
As can be seen from the figure, the raman characteristic displacements of carbendazim and hypothion Raman can be clearly observed after adding 0.5ppm pesticides to apples and pineapples, respectively, and the Raman characteristic displacements of the two pesticides are still clearly recognizable at lower addition concentrations.
Using our micro Raman spectrometer RMS1000 can accurately detect whether there are pesticide residues in the fruit, the results show that apples, bananas, mangoes and pineapples purchased from supermarkets do not contain a lot of pesticides, and can be eaten with confidence.
6.1 Using the accumulation of Oceanhood technology to realize the miniaturization and light weighting of raman spectrometer, a new generation of RMS1000 Raman spectrometer was developed;
6.2 Using surface-enhanced Raman spectroscopy combined with solid-liquid separation method to greatly shorten the detection time, 14 kinds of residual pesticides can be detected, and the detection can be completed in as soon as 20 minutes;
检测项目 | 测试对象 | 最低检出浓度 （mg/L） |
苯菌灵 | 仁果类、柑橘类、瓜果等 | 0.5 |
噻菌灵 | 仁果类、柑橘类、小型浆果、瓜果等 | 0.5 |
多菌灵 | 仁果类、柑橘类、小型浆果、瓜果等 | 0.5 |
甲基硫菌灵 | 仁果类、柑橘类、小型浆果等 | 0.5 |
戊唑醇 | 仁果类、柑橘类等 | 0.5 |
倍硫磷 | 仁果类、柑橘类等 | 0.5 |
腈菌唑 | 仁果类、柑橘类等 | 1 |
敌草快 | 仁果类、柑橘类、瓜果等 | 0.1 |
苯醚甲环唑 | 仁果类、柑橘类、小型浆果等 | 1 |
嘧霉胺 | 仁果类、柑橘类、小型浆果等 | 1 |
地虫硫磷 | 仁果类、柑橘类、小型浆果、瓜果等 | 0.01 |
二嗪磷 | 仁果类、柑橘类等 | 0.3 |
三唑磷 | 仁果类、柑橘类等 | 0.5 |
毒死蜱 | 仁果类、柑橘类等 | 0.5 |
6.3 The pretreatment equipment is highly integrated, using an integrated suitcase integrated design combined with a miniaturized Raman spectrometer to achieve on-site detection of pesticide residues.
The relevant product configurations used in this experiment are as follows.
产品 | 型号 | 数量 |
拉曼光谱仪 | RMS1000 | 1 |
前处理一体箱 | RFSC-1000 | 1 |
液体支架 | SH-721C | 1 |
比色皿 | CVT-721 | 3 |
农残拉曼快速检测试剂盒 | / | 1 |
