Method and electronic device for characterizing, via a spectrometry device, the presence in a product of at least one additive from a predefined set of additives, computer program and associated measuring system

Abstract

Method and electronic device for characterizing, via a spectrometry device, the presence in a product of at least one additive from a predefined set of additives, computer program and associated measuring system This method for characterizing the presence of an additive is implemented by an electronic characterization device connected to the spectrometry device.It comprises: - acquisition (100), from the spectrometry device, of a plurality of mass spectra of the product; - determination (110), from the plurality of mass spectra of the product, of an average mass spectrum (70); - identification (120), from the average mass spectrum, of the set of mass to charge ratio(s) of interest showing the presence of at least one additive present in the product, by applying a classification algorithm by homologous series; - calculation (130), of a concentration in the product of each identified additive, from an overall intensity of the identified additive and the intensity-concentration relationship (60) previously determined for the standard additive associated with the respective identified additive. Figure for the abstract: Figure 7.

Description

Title of the invention: Method and electronic device for characterizing, via a spectrometry device, the presence in a product of at least one additive from a predefined set of additives, computer program and associated measuring system

[0001] The present invention relates to a method for characterizing, via a spectrometry device, the presence in a product of at least one additive from a predefined set of additives.

[0002] The invention also relates to a computer program comprising software instructions which, when executed by a computer, implement such a characterization method.

[0003] The invention also relates to an electronic device for characterizing, via a spectrometry device, the presence in a product of at least one additive from a predefined set of additives; and a measuring system comprising a spectrometry device and such an electronic characterization device.

[0004] The invention relates to the field of product analysis by spectrometry. Spectrometry is used in many technical fields, such as petrochemistry, pharmacy, gas phase chemistry, organic chemistry, physics, astrophysics, biology.

[0005] Given the very close similarity in chemical composition between certain products in a set of products, it is quite difficult to differentiate them from each other. For example, in the field of lubricating oils, it is complex to differentiate recycled oils from non-recycled oils, also called conventional oils, or even original oils. Indeed, recycled oils undergo different stages of re-refining, or various chemical treatments to remove the various impurities (additives, oxidation products), which makes their composition very close to a conventional oil.

[0006] It is nevertheless necessary to be able to distinguish these products from each other. In the field of lubricating oils, it is generally preferable to add an additive to a recycled oil in order to improve its performance, and it is therefore useful to know whether the oil is recycled or not. Furthermore, from an ecological and reuse point of view, it is also interesting to know whether the oil is recycled or not.

[0007] Methods are known for analyzing products, such as lubricating oils, by spectrometry to determine which are the major compounds in these products and to differentiate the products from each other.

[0008] However, these methods can be improved by characterizing the presence in a product of at least one additive from a predefined set of additives.

[0009] The aim of the invention is then to propose a method and an associated electronic device making it possible to characterize, via a spectrometry device, the presence in a product of at least one additive from a predefined set of additives. In other words, the invention contributes to the detection and quantification of the presence of at least one additive from a predefined set of additives.

[0010] For this purpose, the subject of the invention is a method for characterizing, via a spectrometry device, the presence in a product of at least one additive from a predefined set of additives, the spectrometry device comprising a liquid chromatography module capable of separating different polar components of a sample according to their polarity, each polar component of the sample being associated with a respective retention time, the spectrometry device further comprising an ionization source connected to the output of the liquid chromatography module and capable of ionizing the sample, a separation module connected to the output of the ionization source and capable of separating ions from the ionized sample, and a detector connected to the output of the separation module and capable of measuring an ionic flux of the sample, the spectrometry device being capable of delivering, for each sample and for each retention time,a mass spectrum representing an ion flux intensity as a function of a mass to charge ratio, ,

[0011] a set of standard additive(s) being defined for the predefined set of additives, each standard additive being associated with a homologous series of one or more additives of the predefined set of additives, an intensity-concentration relationship between ion flux intensity and concentration of the additive being determined for each standard additive from several mass spectra of said standard additive obtained for several distinct concentrations and several retention times, the ion flux intensity taken into account for each respective concentration being obtained from a mass to charge ratio of interest of the mass spectra of the standard additive,

[0012] the method being implemented by an electronic characterization device capable of being connected to the spectrometry device and comprising the following steps:

[0013] - acquisition, by the spectrometry device, of a plurality of spectra of mass of the product, each mass spectrum being determined for the product and being associated with a respective retention time;

[0014] - determination, from the plurality of mass spectra of the product, of a spectrum average mass, the average mass spectrum being obtained by calculating, for each mass to charge ratio present in at least one of said mass spectra, an average of the ion flux intensity values ​​associated with said mass to charge ratio;

[0015] - identification of an additive present in the product, from the mass spectrum means, by applying a classification algorithm by homologous series; a set of mass to charge ratio(s) of interest being further associated with the identified additive;

[0016] - calculation of a concentration in the product of the identified additive, from a overall intensity of the identified additive and the intensity-concentration relationship previously determined for the standard additive associated with the identified additive, the overall intensity being obtained from one or more unit intensities, each unit intensity being associated with a respective mass-to-charge ratio of the set of mass-to-charge ratio(s) of interest.

[0017] According to other advantageous aspects of the invention, the characterization method comprises one or more of the following characteristics, taken in isolation or in all technically possible combinations:

[0018] - the overall intensity is the unit intensity or the sum of the unit intensities, each unit intensity being obtained by integrating an area under a peak of interest of an extracted ion chromatogram, each extracted ion chromatogram preferably being obtained for a respective mass to charge ratio of the set of mass to charge ratio(s) of interest;

[0019] - the intensity of the ionic flux taken into account for each respective concentration during calibration is done under the peak of interest of the chromatogram of ions extracted from the standard additive;

[0020] - the peak of interest is a peak of the extracted ion chromatogram corresponding to a ion of the homologous series of the standard additive;

[0021] - the method further comprises a step of classifying the product among a plurality of classes based on the concentration of at least one additive of the product,

[0022] the classification preferably being carried out by comparing the concentration of the at least one additive of the product to a respective threshold,

[0023] a respective threshold being preferably predefined for each additive,

[0024] the threshold preferably being a function of a parameter of the product, such as the sulfur content,

[0025] the threshold preferably also having a value chosen from a first value if the sulfur content is high and a second value distinct from the first if the sulfur content is lower;

[0026] - the plurality of classes comprises at least one original product class and one recycled product class;

[0027] - the predefined set of additives includes:

[0028] a diphenylamine of the following formula,

[0029] an alkyl phenol of the following formula, OH I

[0030] a phenolic antioxidant of the following formula,

[0031] - the standard additive set(s) comprises a phenol;

[0032] - the homologous series is a set of compounds having different numbers of CH2 groups in part of their structure, with the same number and location of heteroatoms, as well as the same numbers of rings and double bonds; and

[0033] - the product is a lubricating oil.

[0034] The invention also relates to a computer program comprising software instructions which, when executed by a computer, implement a characterization method as defined above.

[0035] The invention also relates to an electronic device for characterizing, via a spectrometry device, the presence in a product of at least one additive from a predefined set of additives, the spectrometry device comprising a liquid chromatography module capable of separating different polar components of a sample according to their polarity, each polar component of the sample being associated with a respective retention time, the spectrometry device further comprising an ionization source connected to the output of the liquid chromatography module and capable of ionizing the sample, a separation module connected to the output of the ionization source and capable of separating ions from the ionized sample, and a detector connected to the output of the separation module and capable of measuring an ionic flux of the sample, the spectrometry device being capable of delivering, for each sample and for each retention time,a mass spectrum representing an ion flux intensity as a function of a mass to charge ratio, ,

[0036] a set of standard additive(s) being defined for the predefined set of additives, each standard additive being associated with a homologous series of one or more additives of the predefined set of additives, an intensity-concentration relationship between ion flux intensity and additive concentration being determined for each standard additive from several mass spectra of said standard additive obtained for several distinct concentrations and several retention times, the ion flux intensity taken into account for each respective concentration being obtained from a mass-to-charge ratio of interest of the mass spectra of the standard additive,

[0037] the electronic characterization device being capable of being connected to the spectrometry device and comprising:

[0038] - an acquisition module configured to acquire, from the spec device tropometry, a plurality of mass spectra of the product, each mass spectrum being determined for the product and being associated with a respective retention time;

[0039] - a determination module configured to determine, from the plurality of mass spectra of the product, an average mass spectrum, the average mass spectrum being obtained by calculating, for each mass to charge ratio present in at least one of said mass spectra, an average of the ion flux intensity values ​​associated with said mass to charge ratio;

[0040] - an identification module configured to identify an additive present in the produced, from the average mass spectrum, by applying a classification algorithm by homologous series; a set of mass to charge ratio(s) of interest being further associated with the identified additive; and

[0041] - a calculation module configured to calculate a concentration in the product of the identified additive, from an overall intensity of the identified additive and the intensity-concentration relationship previously determined for the standard additive associated with the identified additive, the overall intensity being obtained from one or more unit intensities, each unit intensity being associated with a respective mass-to-charge ratio of the set of mass-to-charge ratio(s) of interest.

[0042] The invention also relates to a measuring system comprising a spectrometry device and an electronic device for characterizing, via the spectrometry device, the presence in a product of at least one additive from a predefined set of additives, the electronic characterization device being connected to the spectrometry device,

[0043] the spectrometry device comprising a liquid chromatography module capable of separating different polar components of a sample according to their polarity, each polar component of the sample being associated with a respective retention time, the spectrometry device further comprising an ionization source connected to the output of the liquid chromatography module and capable of ionizing the sample, a separation module connected to the output of the ionization source and capable of separating ions from the ionized sample, and a detector connected to the output of the separation module and capable of measuring an ionic flux of the sample, the spectrometry device being capable of delivering, for each sample and for each retention time, a mass spectrum representing an intensity of the ionic flux as a function of a mass to charge ratio,

[0044] a set of standard additive(s) being defined for the predefined set of additives, each standard additive being associated with a homologous series of one or more additives of the predefined set of additives, an intensity-concentration relationship between ion flux intensity and concentration of the additive being determined for each standard additive from several mass spectra of said standard additive obtained for several distinct concentrations and several retention times, the ion flux intensity taken into account for each respective concentration being obtained from a mass to charge ratio of interest of the mass spectra of the standard additive,

[0045] the electronic characterization device being as defined above.

[0046] According to other advantageous aspects of the invention, the measuring system comprises one or more of the following characteristics, taken individually or in all technically possible combinations:

[0047] - the ionization source is chosen from the group comprising:

[0048] + an ionization source by electronebulizer;

[0049] + an ionization source by chemical ionization at atmospheric pressure;

[0050] + an ionization source by photoionization at atmospheric pressure; and

[0051] + a laser desorption-ionization ionization source;

[0052] - the spectrometry device is calibrated with at least one standard additive, prea possibly to the characterization of the presence in a product of at least one additive;

[0053] the at least one standard additive preferably comprising a phenol, such as 4-Hexadecyphenol.

[0054] The invention will appear more clearly on reading the description which follows, given solely by way of non-limiting example, and made with reference to the drawings in which:

[0055] [Fig-1] [Fig.l] is a schematic representation of a measuring system according to the invention, comprising a spectrometry device and an electronic device for characterizing the presence in a product of at least one additive from a predefined set of additives;

[0056] [Fig.2] [Fig.2] is a representation of an intensity-concentration relationship, obtained from a standard additive;

[0057] [Fig.3] [Fig.3] represents a basic ion chromatogram obtained from the spectrometry device of [Fig.l];

[0058] [Fig.4] [Fig.4] represents an average mass spectrum obtained via the device of spectrometry of [Fig.l];

[0059] [Fig.5] [Fig.5] is a representation of a classification obtained via an al algorithm for classifying compounds by homologous series;

[0060] [Fig.6] [Fig.6] is a representation of an extracted ion chromatogram for several mass to interest charge ratios; and

[0061] [Fig.7] [Fig.7] is a flowchart of a method, according to the invention, of character determination of the presence in a product of at least one additive from a predefined set of additives; the method being implemented by the electronic characterization device of [Fig.l].

[0062] In [Fig.l], a measuring system 10 comprises a spectrometry device 12. The spectrometry device 12 comprises a liquid chromatography module 13 capable of separating different polar components of a sample according to their polarity. Each polar component of the sample is associated with a respective retention time.

[0063] Those skilled in the art will observe that, in the present application, the sample is the general term used to designate the element introduced into the spectrometry device 12 and for which a mass spectrum, for each retention time, is delivered at the output of the spectrometry device 12. Those skilled in the art will then understand that during a preliminary calibration, the sample is a standard additive, then that during the actual implementation of the characterization method, that is to say during the characterization of a product, the sample is then the product.

[0064] The spectrometry device 12 also comprises an ionization source 14 connected to the output of the liquid chromatography module 13 and capable of ionizing the sample, a separation module 16 connected to the output of the ionization source 14 and capable of separating ions from the ionized sample, and a detector 18 connected to the output of the separation module 16 and capable of measuring an ionic flux of the sample.

[0065] The measuring system 10 also comprises an electronic device 20 for characterizing, via the spectrometry device 12, the presence in a product of at least one additive from a predefined set of additives. The electronic characterization device 20 is connected to the spectrometry device 12.

[0066] The spectrometry device 12 is known per se, and is more particularly a spectrometer, coupled to the liquid chromatography module 13, and making it possible to detect and characterize molecules of interest in the product, by measuring their mass and their retention time, and then to characterize their chemical structure. The mass spectrometry carried out by the spectrometer coupled to the liquid chromatography is then based on the separation in liquid phase or gas phase of the molecules according to the ionization source 14 chosen. The separation is carried out after introducing the sample into the ionization source 14. This differs from a mass spectrometry device with a direct ionization source in the way in which a sample is introduced and prepared for analysis. The spectrometry device 12 is further capable of delivering, for each sample and for each retention time, a mass spectrum representing an intensity, noted I, of the ionic flux as a function of a mass to charge ratio, noted m / z.

[0067] Those skilled in the art will understand that the spectrometer is typically formed of the ionization source 14, the separation module 16 and the detector 18.

[0068] The liquid chromatography module 13 is capable of separating different polar components of a sample. For example, the sample is 4-Hexadecyphenol previously diluted in tetrahydrofuran (THF) with the addition of 2% ammonium hydroxide to promote the deprotonation of the 4-Hexadecyphenol. An approach with the spectrometry device 12 including the chromatography module 13 makes it possible to analyze a compound that is not volatile and that is difficult to vaporize, which makes the spectrometry device 12 useful for analyzing complex organic compounds.

[0069] Those skilled in the art will note that, in the present application, a compound is understood to mean any type of chemical compound in the broad sense, in particular as an additive.

[0070] The ionization source 14 is typically an electrospray ionization source, also called an ESI (ElectroSpray Ionization) type source. Electrospray ionization is the dispersion of a liquid in the form of electrically charged droplets.

[0071] Alternatively, or in addition, the ionization source 14 is a laser desorption-ionization source, also called an LDI type source (from the English Laser Desorption / ionization).

[0072] Alternatively, or additionally, the ionization source 14 is also an atmospheric pressure chemical ionization source, also called an APCI (Atmospheric Pressure Chemical ionization) type source. Atmospheric pressure chemical ionization is more suitable for low mass compounds or apolar compounds.

[0073] Alternatively, or additionally, the ionization source 14 is also an atmospheric pressure photoionization source, also called an APPI (Atmospheric Pressure Photoionization) type source; atmospheric pressure photoionization is suitable for molecules with low polarity. The APPI source differs from the APCI source in that ionizing electrons, which are found in the APCI source, are substituted by UV photons emitted by a vacuum discharge lamp.

[0074] The separation module 16 is likely to comprise two cells connected in cascade, namely an ion mobility spectrometry cell and a mass spectrometry cell connected at the output of the ion mobility spectrometry cell. The ion mobility spectrometry cell, also noted IMS (from the English lon-Mobility Spectrometry), is also called ion mobility cell, and is capable of separating ions according to their mobility. The mass spectrometry cell, also noted MS (from the English Mass Spectrometry'), is capable of separating ions according to their mass / charge ratio, also called mass to charge ratio or mass to charge ratio. When the separation module 16 includes the mass spectrometry cell coupled to the ion mobility spectrometry cell, the spectrometer is then also called coupled spectrometry device, also noted IMS-MS.

[0075] The separation module 16 comprises, for example, a mass spectrometry cell, also known as MS (from the English Mass Spectrometry), capable of separating the ions according to their mass / charge ratio, also called mass to charge ratio or mass to charge ratio, and the spectrometer is then also called a mass spectrometer.

[0076] Alternatively, the separation module 16 comprises two mass spectrometry cells, namely a first mass spectrometry cell and a second mass spectrometry cell, connected in cascade, i.e. coupled together. The spectrometer is then also called a tandem mass spectrometer, also referred to as tandem MS / MS. According to this addition, the first mass spectrometry cell is capable of separating the ions, a collision cell making it possible to fragment the ions, and the second mass spectrometry cell is capable of separating the fragment ions.

[0077] The mass spectrometry cell is for example a high-resolution analyzer, allowing the exact mass of the analytes to be measured, such as an Orbitrap analyzer allowing the trapping of ions under the action of an electrostatic field. The mass spectrum is obtained by the Fourier transform.

[0078] The mass spectrometry cell is for example a high-resolution analyzer, making it possible to measure the exact mass of the analytes, such as a Fourier transform ion cyclotron resonance analyzer, also noted FT-ICR (from the English Fourier-Transform Ion Cyclotron Resonance); a magnetic sector analyzer coupled to an electric sector; and an analyzer based on a time of flight, also noted TOF (from the English Time Of Flight).

[0079] When the mass spectrometry cell is the Fourier transform ion cyclotron resonance analyzer, also known as FT-ICR, the spectrometer is an ion cyclotron resonance mass spectrometer, also known as FT-ICR-MS (from the English Fourier-Transform - Ion Cyclotron Resonance - Mass Spec-trometer). The spectrometer then allows trapping and excitation of ions in an ICR cell (ion cyclotron resonance) under the action of an electromagnetic field. A mass spectrum (not shown) is obtained, for each sample and for each retention time, via the Fourier transform which converts the signal temporal acquired in frequency spectrum proportional to the mass.

[0080] The detector 18 is capable of transforming the ions into an electrical signal. The more ions there are, the greater the current. In addition, the detector 18 is capable of amplifying the signal obtained, in particular so that it can be processed more easily by the electronic characterization device 20.

[0081] A person skilled in the art will then understand, in view of the aforementioned examples, that the spectrometer is in particular of a type chosen from the group comprising: Orbitrap, IMMS, TOF and FT-ICR.

[0082] The electronic characterization device 20 is configured to characterize, i.e. quantify the presence in the product of at least one additive from a set of standard additive(s), defined for the predefined set of additives. In other words, the electronic characterization device 20 is configured to assign a value, such as a concentration, quantifying the presence of a respective additive in the product.

[0083] The product is for example a lubricating oil.

[0084] Furthermore, the characterization device 20 is configured to be calibrated with at least one standard additive from the set of standard additive(s). The standard additive is preferably chosen from the group comprising: 4-Hexadecyphenol, butylated hydroxytoluene, or 4-Nonyl-n-(4-nonylphenyl)aniline.

[0085] In another variant, the set of standard additive(s) preferably comprises a phenol.

[0086] Each standard additive is associated with a homologous series of one or more additives from the predefined set of additives. That is, each standard additive is capable of detecting an additive, from Table 1 below, of a homologous series in the product. A homologous series is a batch of compounds having different numbers of CH2 groups in a part of their structure but with the same number and location of heteroatoms, as well as the same numbers of rings and double bonds. Thus, a homologous series of additives is then a batch of additives having different numbers of CH2 groups in a part of their structure but with the same number and location of heteroatoms, as well as the same numbers of rings and double bonds.

[0087] Calibration is typically performed for several distinct concentrations and several retention times. It should be noted that generally, calculating the particle concentration amounts to determining a number of particles if the volume is predefined. Calculating the concentration of additive particles in the product is then equivalent to quantifying the number of particles of said additive in the product. An intensity-concentration relationship 60 between ion flux intensity and particle concentration is determined for each standard additive from several mass spectra of said standard additive obtained for several distinct concentrations and several retention times, the intensity of the ionic flux taken into account for each respective concentration being obtained from a set of mass to charge ratio(s) of interest of the mass spectra of the standard additive

[0088] The set of mass to charge ratio(s) of interest corresponds for example to one or more mass to charge ratios m / z of homologous series of an ion of the sample before dilution.

[0089] Those skilled in the art will note that, during calibration, the set of mass-to-charge ratio(s) of interest contains only one mass-to-charge ratio m / z of interest corresponding to the ion of the standard additive. During characterization, the set of mass-to-charge ratio(s) of interest contains one or more mass-to-charge ratios of interest depending on the number of homologous series, to the standard additive, having been detected in the product.

[0090] [Tables 1] Additive type Semi-developed formula KMD value Associated standard Mass group + R group Diphenylamine (antioxidant) Ml H AJ IX 0.105 4-Nonyl-n-(4-non ylphenyl) aniline From 2*C6H13 to 2*C16H33 ~ m / z 280 to m / z 560 Alkyl phenol M2 G h .X to 0.069 4-Hexadecyphenol From C0H0 to C38H77 ~ m / z 70 to m / z 735 Phenolic antioxidant M3 0.128 Butylated hydroxytoluene From C6H13 to C31H63 ~ m / z 330 to m / z 690

[0091] The additive types are named M1, M2, and M3. R denotes an alkyl group, linear or branched, saturated or unsaturated, comprising from 1 to 16 carbon atoms. This table is given solely as a non-limiting example, other types of additive associated with other associated standards can be used for the characterization of the presence in a product of at least one additive from the predefined set of additives.

[0092] The electronic characterization device 20 comprises a calibration module 21 capable of determining the intensity-concentration relationship 60 between intensity of the ionic flux and concentration of the additive, this for each standard additive. The electronic characterization device 20 also comprises an acquisition module 22 capable of acquiring, via the spectrometry device 12, a plurality of mass spectra of the product (not shown and different from the mass spectra obtained during the calibration). In addition, the electronic characterization device comprises a determination module 24 capable of determining, from the plurality of mass spectra of the product, an average mass spectrum 70.The electronic characterization device 20 also comprises an identification module 26 capable of identifying an additive present in the product, from the average spectrum 70 and by applying a classification algorithm by homologous series. The electronic characterization device 20 also comprises a calculation module 28 capable of calculating the concentration in the product of the identified additive, from an overall intensity of the identified additive and the intensity-concentration relationship 60 previously determined.

[0093] As an optional addition, the electronic device 20 further comprises a classification module 29, capable of classifying the product among a plurality of classes according to the concentration of at least one additive of the product.

[0094] In the example of [Fig.l], the electronic characterization device 20 comprises an information processing unit 30 formed for example of a memory 32 and a processor 34 associated with the memory 32.

[0095] In the example of [Fig.l], the calibration module 21, the acquisition module 22, the determination module 24, the identification module 26 and the calculation module 28, as well as optionally the classification module 29, are each produced in the form of software, or a software brick, executable by the processor 34. The memory 32 of the electronic characterization device 20 is then capable of storing calibration software determining, via the spectrometry device 12, the intensity-concentration relationship 60 between intensity of the ionic flux and particle concentration; acquisition software, from the spectrometry device 12, of the plurality of mass spectra of the product, each mass spectrum being determined for the product and being associated with a respective retention time; determination software, from the plurality of mass spectra of the product, of the average mass spectrum 70;software for identifying the additive present in the product from the average mass spectrum 70, by applying an algorithm for classifying compounds by homologous series; and software for calculating the concentration in the product of the identified additive, from the overall intensity of the identified additive and the intensity-concentration relationship 60 previously determined; as well as in addition; optionally, software for classifying the product among the plurality of classes based on the concentration of the at least one additive of the product.

[0096] The processor 32 is then able to execute each of the software programs among the calibration software, the acquisition software, the determination software, the identification software and the calculation software, as well as, as an optional addition, the classification software.

[0097] In a variant not shown, the calibration module 21, the acquisition module 22, the determination module 24, the identification module 26 and the calculation module 28, as well as the optional addition the classification module 29, are each produced in the form of a programmable logic component, such as an FPGA (Field Programmable Gate Away), or in the form of a dedicated integrated circuit, such as an ASIC (Application Specific Integrated Circuit).

[0098] When the electronic characterization device 20 is produced in the form of one or more software programs, that is to say in the form of a computer program, it is also capable of being recorded on a medium, not shown, readable by a computer. The computer-readable medium is for example a medium capable of storing electronic instructions and of being coupled to a bus of a computer system. By way of example, the readable medium is an optical disk, a magneto-optical disk, a ROM memory, a RAM memory, any type of non-volatile memory (for example EPROM, EEPROM, FLASH, NVRAM), a magnetic card or an optical card. A computer program comprising software instructions is then stored on the readable medium.

[0099] The calibration module 21 is configured to calibrate, via the spectrometry device 12, the predefined set of additives. Each standard additive is associated with the homologous series of one or more additives of the predefined set of additives. The intensity-concentration relationship 60 between ion flux intensity and concentration of the additive is determined for each standard additive from several mass spectra of said standard additive, obtained for several distinct concentrations and several retention times, as shown in [Fig.2] as an example.

[0100] Calibration is carried out prior to a characterization of the product (described below), and this calibration is then also called pre-calibration, or pre-acquisition calibration. This calibration is also called external calibration, being carried out with the standard additive.

[0101] The acquisition module 22 is configured to acquire, from the spectrometry device 12, the plurality of mass spectra of the product. Each mass spectrum is determined for the product and each mass spectrum is associated with a respective retention time.

[0102] Each mass spectrum typically has several peaks, not shown. Each peak corresponds to a respective value of the mass to charge ratio m / z, having the respective intensity I greater than a threshold, not shown. Those skilled in the art will understand that the value of the mass to charge ratio m / z varies from one peak to another.

[0103] The acquisition module 22 is for example configured to detect each peak of each corresponding mass spectrum by thresholding, a peak being detected when its ion flux intensity I is greater than the threshold defined above.

[0104] The threshold preferably corresponds to a predefined signal-to-noise ratio, for example a signal-to-noise ratio greater than or equal to a predefined minimum value, such as 3. The threshold is then typically equal to a multiple of an average noise of each corresponding mass spectrum, the multiple being greater than or equal to the predefined minimum value, such as 3.

[0105] In other words, for the detection of each peak, the acquisition module 22 is for example configured to determine the average noise of each mass spectrum, to calculate the threshold by multiplying said average noise by the desired multiple, such as 3, then to detect all the local extrema of each spectrum having an ion flux intensity value I greater than or equal to the threshold thus calculated.

[0106] For example, the plurality of mass spectra is used to plot a base 65 ion chromatogram. The base 65 ion chromatogram makes it possible to show, for each sample, the most intense peak 68 of the mass spectrum of a respective retention time, as shown in [Fig.3].

[0107] The determination module 24 is configured to determine, from the plurality of mass spectra of the product, the average mass spectrum 70.

[0108] [Fig.4] is a representation, for example, of the average mass spectrum 70 obtained. Said average mass spectrum 70 is obtained by calculating, for each mass to charge ratio m / z present in at least one of said mass spectra, the average of all the ion flux intensity values ​​associated with said mass to charge ratio m / z.

[0109] The identification module 26 is configured to identify the additive present in the product from the average mass spectrum 70 by applying a homologous series classification algorithm.

[0110] The classification algorithm calculates the Kendrick mass KM for example according to the following equation: [YES] [Math.l] KM = mass (IUP AC or EXPER)}^^

[0112] where KM corresponds to the Kendrick mass,

[0113] IUP AC mass corresponds to a measurement of the mass when the mass of the isotope 12C is fixed at exactly 12 atomic mass units, and

[0114] EXPER mass corresponds to an experimental mass measurement, measured during an experiment.

[0115] The Kendrick mass KM is calculated for each peak 75 of the average mass spectrum 70, previously determined by the determination module 24.

[0116] Then, the Kendrick MKD mass defect is typically calculated according to the following equation:

[0117] [Math.2] KMD=NKM-KM

[0118] where KMD corresponds to the Kendrick mass defect,

[0119] KM corresponds to the Kendrick mass, and

[0120] NKM is the nearest integer rounding of the Kendrick mass KM.

[0121] The Kendrick mass defect KMD is calculated for each peak 75, determined beforehand by the determination module 24. Each peak 75 corresponds for example to a compound.

[0122] Using KMD and NKM values ​​obtained for each compound previously determined by the determination module 24, the compounds are classified by homologous series.

[0123] Knowing the KMD value of the additive to be detected, a set of homologous series(s) of the additive to be detected in the product is then identified. The set of mass to charge ratio(s) of interest is further associated with the identified additive.

[0124] [Fig.5] shows a representation 80 of a classification obtained with the homologous series classification algorithm. Each homologous series corresponding to an alignment of points having substantially the same ordinate on the representation 80, where a homologous series is surrounded for example by an ellipse 85. The set of mass to charge ratio(s) of interest corresponds for example to the points surrounded by the ellipse 85.

[0125] The calculation module 28 is configured to calculate the concentration in the product of the identified additive, from an overall intensity of the identified additive and the intensity-concentration relationship 60 previously determined for the standard additive associated with the identified additive. The overall intensity is obtained from one or more unit intensities. Each unit intensity is associated with a respective mass-to-charge ratio of the set of mass-to-charge ratio(s) of interest.

[0126] Preferably, each unit intensity is obtained from an extracted ion chromatogram 95 (EIC). Each unit intensity is preferably obtained by integrating an area under a peak of interest 98 of the extracted ion chromatogram 95, the area under the peak of interest 98 being advantageously associated with the area of ​​the highest intensity of the extracted ion chromatogram 95.

[0127] The peak of interest 98 is a peak of the extracted ion chromatogram 95 corresponding to an ion of the homologous series of the standard additive. Advantageously, the peak of interest 98 is a peak of the extracted ion chromatogram 95 corresponding to a characteristic ion of the homologous series of the standard additive, such as the ion for which the area under the associated peak is the largest in the extracted ion chromatogram 95. The peak of interest 98 is for example a peak of the extracted ion chromatogram 95 corresponding to a deprotonated form of the homologous series of the standard additive.

[0128] [Fig.6] shows an example set of extracted ion chromatograms 95 representing ion flux intensity as a function of retention time, for several mass-to-charge ratios of interest m / z. The number at the top of each chromatogram corresponds to the retention time of the highest intensity in the extracted ion chromatogram 95.

[0129] Each extracted ion chromatogram 95 is preferably obtained for a respective mass-to-charge ratio of the set of mass-to-charge ratio(s) of interest. In other words, for each mass-to-charge ratio m / z of interest, among the set of mass-to-charge ratio(s) of interest, an extracted ion chromatogram 95 is plotted. Then, the area under the peak of interest 98 is calculated for each extracted ion chromatogram 95. This makes it possible to calculate each unit intensity. Those skilled in the art will further understand that, for each peak, the area of ​​the corresponding peak is equal to the product of the height of said peak, i.e. the intensity value of said peak, and the width of said peak.

[0130] The overall intensity of the additive to be detected, also noted Idet, is preferably equal to the sum of the unit intensities. The concentration of the additive to be detected is then obtained from the overall intensity of the additive to be detected Idet and the intensity-concentration relationship 60, and is noted Cobt, as illustrated in [Fig.2]. When the product does not contain the additive to be detected, then the concentration is negligible compared to the case where the additive to be detected is present in the product.

[0131] Preferably, the classification module 29 is configured to classify the product among the plurality of classes according to the concentration of the at least one additive of the product.

[0132] The plurality of classes preferably comprises at least one original product class and one recycled product class.

[0133] The classification is preferably carried out by comparing the concentration of the at least one additive of the product to a respective threshold. A respective threshold is preferably predefined for each additive.

[0134] The threshold is advantageously a function of a parameter of the product, such as the sulfur content. According to this advantageous aspect, the threshold has, for example, a value chosen from a first value if the sulfur content is high and a second value distinct from the first if the sulfur content is lower. For example, when the additive is an alkyl phenol, if the sulfur content is greater than 0.03%, the first value for the threshold is equal to 100 ppm; and if the sulfur content is less than or equal to 0.03%, the first value for the threshold is equal to 10 ppm.

[0135] Thus, the product is characterized in order to quantify the presence in the product of at least one additive from the predefined set of additives. This makes it possible to know whether the product is a conventional product or a recycled product.

[0136] The operation of the electronic characterization device 20 according to the invention will now be described with regard to [Fig.7] representing a flowchart of the method, according to the invention, for characterizing the presence in the product of at least one additive from the predefined set of additives, said characterization method being implemented by the electronic characterization device 20.

[0137] Prior to the characterization of the product, the calibration is carried out for several distinct concentrations of each standard additive. The intensity-concentration relationship 60 between ion flux intensity and concentration is determined for each standard additive from several mass spectra of said standard additive, obtained for several distinct concentrations and several retention times, the ion flux intensity taken into account for each respective concentration being obtained from a set of mass-to-charge ratio(s) of interest of the mass spectra of the standard additive. Preferably, said intensity is the area under the peak of interest 98 of the extracted ion chromatogram 95 of the standard additive.

[0138] During an initial step 100, the characterization device 20 acquires, via its acquisition module 22 and from the spectrometry device 12, the plurality of mass spectra of the product, each mass spectrum being determined for the product and being associated with a respective retention time.

[0139] The acquisition step 100 typically comprises the detection, by thresholding, of the peak(s) of the plurality of respective mass spectra, each detected peak then having the ion flux intensity greater than the threshold, said peak preferably corresponding to a predefined signal-to-noise ratio.

[0140] At the end of the acquisition step 100, the characterization device 20 moves on to a next step 110 during which it determines, via its determination module 22 and from the plurality of mass spectra of the product, the average mass spectrum 70. Thus, each compound corresponds to a peak 75 of the respective average mass spectrum 70 and its determination is based on the mass to charge ratio for said peak 75, the intensity of the ionic flux and the mass to charge ratio for said peak 75 being associated with each compound.

[0141] During the following step 120, the characterization device 20 identifies, via its identification module 24, the additive present in the product from the spectrum of average mass 70, by applying the homologous series classification algorithm and finding a KMD value corresponding to the homologous series of the standard additive and the product. An example representation of the classification algorithm is shown in [Fig.5].

[0142] At the end of the identification step 120, the characterization device 20 moves on to the last step 130 during which it calculates, via its calculation module 28, the concentration of the additive in the product.

[0143] The calculation module 28 makes it possible to quantify the concentration from the classification of compounds by homologous series, by selecting the homologous series present in the standard additive and in the product. Given that each compound corresponds to a peak 75 of the average mass spectrum 70 and is determined from the mass to charge ratio for said peak 75, the intensity of the ionic flux and the mass to charge ratio for said peak 75 are associated with each compound. Consequently, the intensities of the ionic flux of a group of compound(s) comprising the same homologous series are known. From the overall intensity and the intensity-concentration relationship 60 determined during the calibration, the concentration of the additive to be detected in the product is calculated.

[0144] The characterization method and the electronic characterization device 20 according to the invention then make it possible to calculate the quantity of each additive identified as present in the product. Thus, the characterization method makes it possible to differentiate several products to be analyzed, by identifying the additives present in each product, while quantifying the presence of each identified additive, with the calculation of the concentration of each identified additive.

Claims

Claims

1. Method for characterizing, via a spectrometry device (12), the presence in a product of at least one additive from a predefined set of additives, the spectrometry device (12) comprising a liquid chromatography module (13) capable of separating different polar components of a sample according to their polarity, each polar component of the sample being associated with a respective retention time, the spectrometry device (12) further comprising an ionization source (14) connected to the output of the liquid chromatography module (13) and capable of ionizing the sample, a separation module (16) connected to the output of the ionization source (14) and capable of separating ions from the ionized sample, and a detector (18) connected to the output of the separation module (16) and capable of measuring an ionic flux of the sample, the spectrometry device (12) being capable of delivering,for each sample and for each retention time, a mass spectrum representing an intensity (I) of the ionic flux as a function of a mass to charge ratio (m / z), a set of standard additive(s) being defined for the predefined set of additives, each standard additive being associated with a homologous series of one or more additives of the predefined set of additives, an intensity-concentration relationship (60) between intensity of the ionic flux and concentration of the additive being determined for each standard additive from several mass spectra of said standard additive obtained for several distinct concentrations and several retention times, the intensity of the ionic flux taken into account for each respective concentration being obtained from a mass to charge ratio (m / z) of interest of the mass spectra of the standard additive,the method being implemented by an electronic characterization device (20) capable of being connected to the spectrometry device (12) and comprising the following steps:, - acquisition (100), from the spectrometry device, of a plurality of mass spectra of the product, each mass spectrum being determined for the product and being associated with a respective retention time; - determination (110), from the plurality of mass spectra of the product, of an average mass spectrum (70), the average mass spectrum (70) being obtained by calculation, for each mass to charge ratio (m / z) present in at least one of said mass spectra, of an average of the ion flux intensity values ​​associated with said mass to charge ratio (m / z); - identification (120), of an additive present in the product, from the average mass spectrum (70), by applying a homologous series classification algorithm; a set of mass to charge ratio(s) of interest being further associated with the identified additive; - calculation (130), of a concentration in the product of the identified additive, from an overall intensity of the identified additive and the intensity-concentration relationship (60) previously determined for the standard additive associated with the identified additive, the overall intensity being obtained from one or more unit intensities, each unit intensity being associated with a respective mass to charge ratio of the set of mass to charge ratio(s) of interest.

2. A method according to claim 1, wherein the overall intensity is the unit intensity or the sum of the unit intensities, each unit intensity being obtained by integrating an area under a peak of interest (98) of an extracted ion chromatogram (95), each extracted ion chromatogram (95) preferably being obtained for a respective mass-to-charge ratio (m / z) of the set of mass-to-charge ratio(s) of interest.

3. A method according to claim 1 or 2, wherein the ion flux intensity considered for each respective concentration during calibration is an area under the peak of interest (98) of the extracted ion chromatogram (95) of the standard additive.

4. A method according to claim 2 or 3, wherein the peak of interest (98) is a peak of the extracted ion chromatogram (95) corresponding to an ion of the homologous series of the standard additive.

5. A method according to claim 1, wherein the method further comprises a step (140) of classifying the product among a plurality of classes, depending on the concentration of at least one additive of the product, the classification preferably being carried out by comparing the concentration of the at least one additive of the product to a respective threshold, a respective threshold preferably being predefined for each additive, the threshold preferably depending on a parameter of the product, such as the sulfur content, the threshold preferably further having a value chosen from a

6.

7. first value if the sulfur content is high and a second value distinct from the first if the sulfur content is lower. The method of claim 5, wherein the plurality of classes comprises at least one original product class and one recycled product class. Method according to one of claims 1 to 6, in which the predefined set of additives comprises: - a diphenylamine (Ml) of the following formula, an alkyl phenol (M2) of the following formula, HAS a phenolic antioxidant (M3) of the following formula,

8.

9.

10.

11. Method according to one of claims 1 to 6, in which the set of standard additive(s) comprises a phenol. A method according to any preceding claim, wherein the homologous series is a batch of compounds having different numbers of CH2 groups in part of their structure, with the same number and location of heteroatoms, as well as the same numbers of rings and double bonds. A method according to any preceding claim, wherein the product is a lubricating oil. A computer program comprising software instructions which, when executed by a computer, implement a process according to any one of the preceding claims.

12. Electronic device (20) for characterizing, via a spectrometry device (12), the presence in a product of at least one additive from a predefined set of additives, the spectrometry device (12) comprising a liquid chromatography module (13) capable of separating different polar components of a sample according to their polarity, each polar component of the sample being associated with a respective retention time, the spectrometry device (12) further comprising an ionization source (14) connected to the output of the liquid chromatography module (13) and capable of ionizing the sample, a separation module (16) connected to the output of the ionization source (14) and capable of separating ions from the ionized sample, and a detector (18) connected to the output of the separation module (16) and capable of measuring an ionic flux of the sample, the spectrometry device (12) being capable of delivering,for each sample and for each retention time, a mass spectrum representing an intensity (I) of the ionic flux as a function of a mass to charge ratio (m / z), a set of standard additive(s) being defined for the predefined set of additives, each standard additive being associated with a homologous series of one or more additives of the predefined set of additives, an intensity-concentration relationship (60) between intensity of the ionic flux and concentration of the additive being determined for each standard additive from several mass spectra of said standard additive obtained for several distinct concentrations and several retention times, the intensity of the ionic flux taken into account for each respective concentration being obtained from a mass to charge ratio (m / z) of interest of the mass spectra of the standard additive,the electronic characterization device (20) being able to be connected to the spectrometry device (12) and comprising: - an acquisition module (22) configured to acquire, from the spectrometry device, a plurality of mass spectra of the product, each mass spectrum being determined for the product and being associated with a respective retention time;, - a determination module (24) configured to determine, from the plurality of mass spectra of the product, an average mass spectrum (70), the average mass spectrum (70) being obtained by calculating, for each mass to charge ratio (m / z) present in at least one of said mass spectra, an average of the flux intensity values ionic associated with said mass to charge ratio (m / z); - an identification module (26) configured to identify an additive present in the product, from the average mass spectrum (70), by applying a classification algorithm by homologous series; a set of mass to charge ratio(s) of interest being further associated with the identified additive; and - a calculation module (28) configured to calculate a concentration in the product of the identified additive, from an overall intensity of the identified additive and the intensity-concentration relationship (60) previously determined for the standard additive associated with the identified additive, the overall intensity being obtained from one or more unit intensities, each unit intensity being associated with a respective mass to charge ratio of the set of mass to charge ratio(s) of interest.

13. Measuring system (10) comprising a spectrometry device (12) and an electronic device (20) for characterizing, via the spectrometry device (12), the presence in a product of at least one additive from a predefined set of additives, the electronic characterization device (20) being connected to the spectrometry device (12), the spectrometry device (12) comprising a liquid chromatography module (13) capable of separating different polar components of a sample according to their polarity, each polar component of the sample being associated with a respective retention time, the spectrometry device (12) further comprising an ionization source (14) connected to the output of the liquid chromatography module (13) and capable of ionizing the sample, a separation module (16) connected to the output of the ionization source (14) and capable of separating ions from the ionized sample,and a detector (18) connected to the output of the separation module (16) and capable of measuring an ionic flux of the sample, the spectrometry device (12) being capable of delivering, for each sample and for each retention time, a mass spectrum representing an intensity (I) of the ionic flux as a function of a mass to charge ratio (m / z), a set of standard additive(s) being defined for the predefined set of additives, each standard additive being associated with a homologous series of one or more additives of the predefined set of additives, an intensity-concentration relationship (60) between intensity of the ionic flux and concentration of the additive being determined for each standard additive from several mass spectra of said standard additive obtained for, several distinct concentrations and several retention times, the intensity of the ionic flux taken into account for each respective concentration being obtained from a mass to charge ratio (m / z) of interest of the mass spectra of the standard additive, characterized in that the electronic characterization device (20) is according to the preceding claim.

14. The system (10) of claim 13, wherein the ionization source is selected from the group comprising: - an ionization source by electronebulizer; - an ionization source by chemical ionization at atmospheric pressure; - an ionization source by photoionization at atmospheric pressure; and - a laser desorption-ionization ionization source.

15. A system (10) according to claim 13 or 14, wherein the device spectrometry (12) is calibrated with at least one standard additive, prior to characterizing the presence in a product of at least one additive; the at least one standard additive preferably comprising a phenol, such as 4-Hexadecyphenol.

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