Method and electronic device for characterizing, via a spectrometric device, the presence in a product of at least one additive from a predefined set of additives, associated computer program and measurement 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, associated computer program and measurement 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), by 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 in the product, by applying a classification algorithm using 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 spectrometric device, the presence in a product of at least one additive from a predefined set of additives, associated computer program and measurement 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 process.

[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 measurement 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, pharmaceuticals, gas chemistry, organic chemistry, physics, astrophysics, and biology.

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

[0006] It is nevertheless necessary to be able to distinguish these products from one another. In the field of lubricating oils, it is generally preferable to add an additive to recycled oil to improve its performance, and it is therefore useful to know whether the oil is recycled or not. Furthermore, from an environmental and reuse perspective, it is also important 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 object of the invention is to provide a method and an associated electronic device for characterizing, via a spectrometric 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] To this end, the 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, 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 the intensity of the ionic flux 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 from the predefined set of additives, an intensity-concentration relationship between the intensity of the ionic flux and the 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 of interest from the mass spectra of the standard additive,

[0012] the process being implemented by an electronic characterization device suitable for connection 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 of 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 average, by applying a classification algorithm using homologous series; a set of mass-to-load 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 global intensity of the identified additive and of the intensity-concentration relationship previously determined for the standard additive associated with the identified additive, the global 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 features, taken individually 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 a chromatogram of extracted ions, each chromatogram of extracted ions 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 in the chromatogram of extracted ions corresponding to a ion of the homologous series of the standard additive;

[0021] - the process further includes a step of classifying the product among a plurality of classes depending on the concentration of at least one additive of the product,

[0022] the classification preferably being carried out by comparing the concentration of 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 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 includes at least one original product class and a recycled product class;

[0027] - the predefined set of additives comprises:

[0028] a diphenylamine of the following formula,

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

[0030] a phenolic antioxidant of the following formula,

[0031] - the standard additive(s) set includes 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 number 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 process 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 the intensity of the ionic flux 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 from the mass spectra of the standard additive,

[0037] the electronic characterization device being suitable for connection to the spectrometry device and comprising:

[0038] - an acquisition module configured to acquire, from the spec device trometry, 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 homologous series classification algorithm; 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 measurement 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 from the predefined set of additives, an intensity-concentration relationship between the intensity of the ionic flux and the 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 of interest from 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 features, taken individually or in all technically possible combinations:

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

[0048] + an ionization source by electron fogger;

[0049] + a chemical ionization source at atmospheric pressure;

[0050] + an atmospheric pressure photo-ionization ionization source; and

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

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

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

[0054] The invention will become clearer upon reading the following description, given solely by way of non-limiting example, and made with reference to the drawings in which:

[0055] [Fig-1] [Fig.1] is a schematic representation of a measurement 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 the [Fig.1];

[0058] [Fig.4] [Fig.4] represents an average mass spectrum obtained via the device spectrometry of the [Fig.1];

[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 a chromatogram of ions extracted for several interest expense ratios; and

[0061] [Fig.7] [Fig.7] is a flowchart of a process, according to the invention, of a character measurement of the presence in a product of at least one additive from a predefined set of additives; the process being implemented by the electronic characterization device of the [Fig.1].

[0062] In [Fig. 1], a measurement system 10 comprises a spectrometry device 12. The spectrometry device 12 includes 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] The person 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. The person skilled in the art will then understand that during a preliminary calibration, the sample is a standard additive, and then during the actual implementation of the characterization process, that is to say during the characterization of a product, the sample is then the product.

[0064] The spectrometry device 12 also includes 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 from the sample.

[0065] The measurement system 10 also includes 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 in itself, and is more particularly a spectrometer, coupled to the liquid chromatography module 13, and enabling the detection and characterization of molecules of interest in the product by measuring their mass and retention time, and thus characterizing their chemical structure. The mass spectrometry performed by the spectrometer coupled to liquid chromatography is then based on the separation of molecules in the liquid or gas phase, depending on 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 that a The sample is introduced and prepared for analysis. The spectrometry device 12 is also capable of delivering, for each sample and for each retention time, a mass spectrum representing an intensity, denoted I, of the ionic flux as a function of a mass-to-charge ratio, denoted m / z.

[0067] A person 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, having been previously diluted in tetrahydrofuran (THF) with the addition of 2% ammonium hydroxide to promote the deprotonation of 4-Hexadecyphenol. An approach using the spectrometry device 12, which includes the chromatography module 13, makes it possible to analyze a compound that is not volatile and is difficult to vaporize, thus making the spectrometry device 12 useful for the analysis of complex organic compounds.

[0069] A person skilled in the art will note that, in the present application, a compound is understood to mean any type of chemical compound in the broadest sense, including an additive.

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

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

[0072] Alternatively, or in addition, 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 or nonpolar compounds.

[0073] Alternatively, or as a complement, 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 slightly polar molecules. The APPI source differs from the APCI source in that the ionizing electrons found in the APCI source are replaced by UV photons emitted by a vacuum discharge lamp.

[0074] The separation module 16 is likely to comprise two cascaded cells, namely an ion mobility spectrometry cell and a mass spectrometry cell connected to the output of the ion mobility spectrometry cell. The ion mobility spectrometry cell, also denoted IMS (from the English Ion-Mobility Spectrometry (IMS-MS) is also called an ion mobility cell and is capable of separating ions based on their mobility. Mass spectrometry, also denoted MS, is capable of separating ions based on their 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 a coupled spectrometry instrument, also denoted IMS-MS.

[0075] The separation module 16 includes, for example, a mass spectrometry cell, also noted MS (from the English Mass Spectrometry), capable of separating ions according to their mass / charge ratio, also called 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 to each other. The spectrometer is then also called a tandem mass spectrometer, also denoted tandem MS / MS. According to this addition, the first mass spectrometry cell is capable of separating ions, a collision cell enabling the fragmentation of the ions, and the second mass spectrometry cell is capable of separating the fragmented ions.

[0077] The mass spectrometry cell is, for example, a high-resolution analyzer that allows for the precise measurement of the analytes' mass, such as an Orbitrap analyzer that traps ions under the influence 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, allowing the exact mass of analytes to be measured, 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 electrical sector; and a time-of-flight based analyzer, also noted TOF (from the English Time Of Flight).

[0079] When the mass spectrometry cell is the Fourier transform ion cyclotron resonance analyzer, also denoted FT-ICR, the spectrometer is an ion cyclotron resonance mass spectrometer, also called FT-ICR-MS (from the English Fourier-Transform - Ion Cyclotron Resonance - Mass Spectrometer). The spectrometer then allows the trapping and excitation of ions in an ICR (ion cyclotron resonance) cell 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 that converts the signal time acquired in frequency spectrum proportional to mass.

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

[0081] The 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, that is, to 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 standard additive set(s) preferably includes 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 set 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 number of rings and double bonds. Thus, a homologous series of additives is a set 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 number of rings and double bonds.

[0087] Calibration is typically performed for several distinct concentrations and retention times. It should be noted that, generally, calculating the particle concentration amounts to determining the 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 between the intensity of the ionic flux and the 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] A person skilled in the art will note that, during calibration, the set of mass-to-charge ratios 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 ratios of interest contains one or more mass-to-charge ratios of interest depending on the number of homologous series, to the standard additive, that have 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-nonylphenyl)aniline From 2*C6H13 to 2*C16H33 ~ m / z 280 to m / z 560 Alkylphenol 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 designated M1, M2, and M3. R designates an alkyl group, linear or branched, saturated or unsaturated, comprising from 1 to 16 carbon atoms. This table is given only as a non-limiting example; other additive types associated with other associated standards may be used for the characterization of the The presence in a product of at least one additive from the predefined set of additives.

[0092] The electronic characterization device 20 includes a calibration module 21 capable of determining the intensity-concentration relationship 60 between the intensity of the ionic flux and the concentration of the additive, for each standard additive. The electronic characterization device 20 also includes 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 calibration). In addition, the electronic characterization device includes 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 includes an identification module 26 capable of identifying an additive present in the product, from the average spectrum 70 and by applying a classification algorithm using homologous series. The electronic characterization device 20 also includes 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 complement, the electronic device 20 further includes 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.1], the electronic characterization device 20 includes 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. 1], 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 implemented as a software program, or a software component, executable by the processor 34. The memory 32 of the electronic characterization device 20 is then capable of storing calibration software that determines, via the spectrometry device 12, the intensity-concentration relationship 60 between the intensity of the ionic flux and the concentration of particles; software for acquiring, 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; software for determining, from the plurality of mass spectra of the product, 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 a software to classify the product among the plurality of classes according to the concentration of at least one additive in the product.

[0096] The processor 32 is then capable of running each of the software among the calibration software, the acquisition software, the determination software, the identification software and the calculation software, as well as, as an optional complement, the classification software.

[0097] In an alternative 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, as an optional complement, the classification module 29, are each implemented 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 Specified Integrated Circuit).

[0098] When the electronic characterization device 20 is implemented in the form of one or more software programs, i.e., in the form of a computer program, it is also capable of being stored on a computer-readable medium (not shown). The computer-readable medium is, for example, a medium capable of storing electronic instructions and being connected to a bus of a computer system. For example, the readable medium is an optical disc, a magneto-optical disc, a ROM, a RAM, any type of non-volatile memory (e.g., EPROM, EEPROM, FLASH, NVRAM), a magnetic card, or an optical card. A computer program containing 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 from the predefined set of additives. The intensity-concentration relationship 60 between the intensity of the ion flux and the 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] by way of example.

[0100] Calibration is performed prior to product characterization (described later), and this calibration is then also called pre-calibration, or pre-acquisition calibration. This calibration is also called external calibration, as it is performed with the calibration 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 specific value of the mass-to-load ratio (m / z), with the respective intensity I exceeding a threshold (not shown). Those skilled in the art will understand that the value of the mass-to-load ratio (m / z) varies from one peak to the next.

[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, and then to detect all 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] Figure 4 is a representation, for example, of the average mass spectrum 70 obtained. Said mean 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 mass of Kendrick,

[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 mean mass spectrum 70, previously determined by the determination module 24.

[0116] Next, 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 fault,

[0119] KM corresponds to the mass of Kendrick, and

[0120] NKM is the rounded-to-the-nearest integer of the mass of Kendrick KM.

[0121] The Kendrick KMD mass defect is calculated for each peak 75, previously determined 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 into homologous series.

[0123] By knowing the KMD value of the additive to be detected, a set of homologous series 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] Figure 5 shows a representation 80 of a classification obtained with the homologous series classification algorithm. Each homologous series corresponds to an alignment of points having substantially the same ordinate on the representation 80, where a homologous series is enclosed, for example, by an ellipse 85. The set of mass-to-charge ratio(s) of interest corresponds, for example, to the points enclosed by the ellipse 85.

[0125] The calculation module 28 is configured to calculate the concentration in the product of the identified additive, based on 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-load ratio from the set of mass-to-load ratios of interest.

[0126] Preferably, each unit intensity is obtained from an Extracted Ion Chromatogram (EIC). Each unit intensity is preferably obtained by integrating an area under a peak of interest from the Extracted Ion Chromatogram, the area under the peak of interest being advantageously associated with the area of ​​the highest intensity in the Extracted Ion Chromatogram.

[0127] The peak of interest 98 is a peak in the chromatogram of extracted ions 95 corresponding to an ion of the homologous series of the standard additive. Advantageously, the peak of interest 98 is a peak in the chromatogram of extracted ions 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 chromatogram of extracted ions 95. The peak of interest 98 is, for example, a peak in the chromatogram of extracted ions 95 corresponding to a deprotonated form of the homologous series of the standard additive.

[0128] Figure 6 shows an example of an ensemble of extracted ion chromatograms representing the intensity of the ion flux 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.

[0129] Each extracted ion chromatogram 95 is preferably obtained for a respective mass-to-charge ratio from the set of mass-to-charge ratios of interest. In other words, for each mass-to-charge ratio m / z of interest from the set of mass-to-charge ratios 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 allows the individual intensity to be calculated. 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 denoted 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 denoted 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 at least one additive of the product.

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

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

[0134] The threshold is advantageously a function of a product parameter, such as the sulfur content. According to this advantageous feature, 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 determine 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 reference to [Fig.7] representing a flowchart of the process, according to the invention, of characterizing the presence in the product of at least one additive from the predefined set of additives, said characterization process being implemented by the electronic characterization device 20.

[0137] Prior to product characterization, calibration is performed 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 considered for each respective concentration being obtained from a set of mass-to-charge ratio(s) of interest from the mass spectra of the standard additive. Preferably, said intensity is the area under the peak of interest 98 of the chromatogram of ions extracted 95 from 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 involves the detection, by thresholding, of the peak(s) of the plurality of respective mass spectra, each detected peak then exhibiting the ion flux intensity greater than the threshold, said single preferably corresponding to a predefined signal-to-noise ratio.

[0140] At the end of the acquisition step 100, the characterization device 20 proceeds to a subsequent 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] In the next 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 of the classification algorithm representation is shown in [Fig. 5].

[0142] At the end of the identification step 120, the characterization device 20 moves 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 allows the concentration to be quantified from the classification of compounds by homologous series, by selecting the homologous series present in the standard additive and in the product. Since 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 ionic flux intensities of a group of compound(s) containing the same homologous series are known. From the overall intensity and the intensity-concentration relationship 60 determined during calibration, the concentration of the additive to be detected in the product is calculated.

[0144] The characterization process 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 process 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

Demands

1. A 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 from 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 from the predefined set of additives, an intensity-concentration relationship (60) between the intensity of the ionic flux and the 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 process being implemented by an electronic characterization device (20) suitable for connection to the spectrometry device (12) and comprising the following steps:, - acquisition (100), by 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 ionic 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 classification algorithm by homologous series; 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 intensity of the ion flux taken into account for each respective concentration during calibration is an area under the peak of interest (98) of the chromatogram of extracted ions (95) from the standard additive.

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

5. A method according to claim 1 of any one of the preceding claims, wherein the method further comprises a step (140) of classifying the product into a plurality of classes, based on the concentration of at least one additive of the product, the classification preferably being carried out by comparing the concentration of 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 also having a value chosen from a

6.

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

8.

9.

10.

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

12. An 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 from 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 from the predefined set of additives, an intensity-concentration relationship (60) between the intensity of the ionic flux and the 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 suitable for connection 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 the 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 using 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. Measurement 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 at 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 from the predefined set of additives, an intensity-concentration relationship (60) between the intensity of the ionic flux and the 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 from the mass spectra of the standard additive, characterized in that the electronic characterization device (20) is according to the preceding claim.

14. System (10) according to claim 13, wherein the ionization source is selected from the group comprising: - an ionization source using an electron fogger; - a chemical ionization source at atmospheric pressure; - a photo-ionization source at atmospheric pressure; and - a laser desorption-ionization ionization source.

15. 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; at least one standard additive preferably comprising a phenol, such as 4-Hexadecyphenol.

Images