Inductively coupled plasma (ICP) mass spectroscopy is an analysis technique commonly used for the determination of trace element concentrations and isotope ratios in liquid samples. ICP mass spectroscopy employs electromagnetically generated partially ionized argon plasma which reaches a temperature of approximately 7000K. When a sample is introduced to the plasma, the high temperature causes sample atoms to become ionized or emit light. Since each chemical element produces a characteristic mass or emission spectrum, measuring said spectra allows the determination of the elemental composition of the original sample.
Sample introduction systems may be employed to introduce the liquid samples into the ICP mass spectroscopy instrumentation (e.g., an inductively coupled plasma mass spectrometer (ICP/ICPMS), an inductively coupled plasma atomic emission spectrometer (ICP-AES), or the like) for analysis. For example, a sample introduction system may withdraw an aliquot of a liquid sample from a container and thereafter transport the aliquot to a nebulizer that converts the aliquot into a polydisperse aerosol suitable for ionization in plasma by the ICP mass spectrometry instrumentation. The aerosol is then sorted in a spray chamber to remove the larger aerosol particles. Upon leaving the spray chamber, the aerosol is introduced to the ICPMS or ICPAES instruments for analysis. Often, the sample introduction is automated to allow a large number of samples to be introduced into the ICP mass spectroscopy instrumentation in an efficient manner.
Systems and methods for automated handling of homogenous nanoparticle standard solutions with subsequent inline introduction to sample solutions prior to analysis are described. A system embodiment includes, but is not limited to, an agitator configured to mix a nanoparticle standard solution in a container to provide a mixed nanoparticle standard having a substantially homogenous distribution of nanoparticles; and a fluid preparation system fluidically coupled with the container to receive the mixed nanoparticle standard, the fluid preparation system including a valve system and one or more pumps configured to direct the mixed nanoparticle standard through the valve system and into contact with a fluid sample stream for inline mixing with the fluid sample stream to provide a mixed sample and nanoparticle standard fluid prior to transfer to an analysis system.
A method embodiment includes, but is not limited to, mixing, via an agitator, a nanoparticle standard solution in a container to provide a mixed nanoparticle standard having a substantially homogenous distribution of nanoparticles; transferring, via a fluid line, the mixed nanoparticle standard to a fluid preparation system including a valve system and one or more pumps; and directing, via the one or more pumps, the mixed nanoparticle standard through the valve system and into contact with a fluid sample stream to inline mix with the fluid sample stream and provide a mixed sample and nanoparticle standard fluid prior to transfer to an analysis system.
This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.
The Detailed Description is described with reference to the accompanying figures.
Nanoparticle research has grown to encompass applications from the medical industry to the environmental industry. Such applications can focus on capabilities to detect nanoparticles (e.g., particles of less than 1000 nm in diameter) and to calculate the sizes of nanoparticles present in a sample. However, determining what is a nanoparticle and what is not a nanoparticle when analyzing spectrometry data poses many challenges. For instance, spectrometry data, such as ICPMS data, includes information associated with ionized samples and background interference, such as resulting from plasma gases introduced to the ICP torch, that can overlap with data associated with small nanoparticles. For example, as the size of the nanoparticle decreases, the spectrometry data of the nanoparticle begins to converge with data associated with ionic species produced by the ICP torch. This overlap and the associated challenges with removing background interferences, while avoiding nanoparticle data removal, lead to continued problems in providing reliable data associated with nanoparticles, including, but not limited to, identification of nanoparticles and determining the number of nanoparticles and their associated size distributions.
Nanoparticle standards or reference materials (RMs) can be utilized to determine transport efficiency of samples that could contain nanoparticles, providing an opportunity to determine nanoparticle concentration and nanoparticle size in the sample based on the known standards. Example nanoparticle standards can include suspensions of gold nanoparticles provided in a liquid matrix, where the standard suspensions include nanoparticles having a known concentration and size or size distribution. The nanoparticle standards can vary depending on the desired sample analysis, where the material of nanoparticles, the matrix of the nanoparticles, the concentration of the nanoparticles, the size of the nanoparticles, or the like, or combinations thereof can change between samples.
Since many nanoparticle standards can be utilized for sample analyses, various containers of the nanoparticle standards may be idle while awaiting use, which can cause nanoparticles to settle within the container. Settling of the nanoparticles can negatively affect the concentration of the standards by providing localized concentration differences within the container, where drawing a volume of standard from within the container may result in a concentration of nanoparticles that significantly differs from the purported standard concentration. While the container can be mixed prior to use, the task of mixing can be time-consuming when multiple sample containers are awaiting analysis at an autosampler. For instance, prolonged mixing of the nanoparticle standard can cause damage to the nanoparticles, preventing bulk mixing of multiple containers. Moreover, the nanoparticle standard often cannot preloaded into a sample container prior to uptake by an autosampler probe (e.g., by directly introducing the standard into a sample container of a sample waiting to be analyzed), since many chemicals provided in the sample can dissolve or otherwise damage the nanoparticles in the standard, preventing an accurate analysis, particularly where a significant duration of time passes between introduction of the standard and uptake of the mixed sample and standard by the autosampler. Thus, a laboratory staff member typically adds the nanoparticle standards to a sample just prior to sample analysis to minimize the time the sample interacts with the nanoparticle standard. For multiple samples, the laboratory staff has numerous tasks to prepare the standards and samples for analysis to avoid damage to the nanoparticle standards, resulting in high costs, multiple opportunities for introduction of error (e.g., incorrect standard used for a particle sample, incorrect volume of standard used, incorrect time of introduction of standard, etc.), and other inefficiencies in sample analysis.
Accordingly, in one aspect, the present disclosure is directed to systems and methods for automated handling of homogenous nanoparticle standard solutions with subsequent introduction to one or more fluid samples with automated inline introduction to the fluid sample at a designated time prior to analysis. A system embodiment includes an agitator to mix a nanoparticle standard container prior to drawing a volume of homogenized nanoparticle standard into an isolated fluid path having a precise volume (e.g., via pump or vacuum introduction). The system can include a pump system and a valve system to direct the nanoparticle standard from the isolated fluid path into a sample stream to mix with the sample while the sample is directed to a sample analysis system (e.g., to a nebulizer of an ICP analysis system). The system can automatically introduce, between samples, a rinse fluid into the fluid path used to transfer and isolate the nanoparticle solution to clean the fluid lines prior to introduction of a different nanoparticle standard. A purge gas can follow the rinse fluid to remove trace amounts of rinse fluid in the fluid lines to prevent mixture between the rinse fluid and subsequent nanoparticle standards (e.g., to avoid imprecise dilution therebetween).
Referring generally to
The fluid preparation system 106 can include a valve system 112 including one or more valves and a pump/vacuum system 114 including one or more pumps and/or one or more vacuum sources to facilitate automated transport of fluids through the system 100. An example fluid preparation system 106 is described further herein with reference to
Referring to
The system 100 is shown in
Referring to
In implementations, the vacuum loader 300 is operated for a duration to draw the substantially homogenous nanoparticle standard solution from container 200B to fill the entire standard holding loop 206, with excess standard solution pulled back into the valve 208 (e.g., towards the vacuum loader) in the fluid line 302. For example, the standard holding loop 206 can be a fluid line (e.g., fluid coil, etc.) having a known volume such that the valve 208 can trap a precise amount of the nanoparticle standard within the standard holding loop 206. In implementations, the standard holding loop 206 is a 0.5 mL volume holding loop, however the system 100 is not limited to such size of holding loop and can include the standard holding loop 206 with volumes less than 0.5 mL or volumes greater than 0.5 mL.
During the load configuration, the agitator 102 can be in a deactivated state where no agitation or mixing of the nanoparticle standards is occurring (e.g., as shown in
Referring to
In implementations, the inject configuration of the valve 208 fluidically couples the vacuum loader 300 and the selection valve 204. For example, in the inject configuration, the valve 208 fluidically couples the first port 208A with the third port 208C to fluidically couple the vacuum loader 300 with the selection valve 204, bypassing the standard holding loop 206. The system 100 can deactivate the vacuum loader 300 when the system 100 is in the nanoparticle standard loaded state to prevent further drawing of nanoparticle standard from the containers (e.g., containers 200A, 200B), which can permit the system 100 to minimize the amount of standard used for each analysis.
Referring to
The valve 506 can be a selector valve as described with reference to selector valve 204 to mix two incoming fluid streams, such as a fluid sample with the nanoparticle standard solution. For instance, the valve 506 is also fluidically coupled with a sample inlet portion 510 configured to supply a fluid sample to the valve 506 (e.g., for mixing of the sample and the nanoparticle standard prior to sending the fluid sample to the analysis system 110). For example, the sample inlet portion 510 is shown with a diluted sample loop 512 configured to hold a particular volume of fluid sample and a sample valve 514 fluidically coupled with a sample source to receive a fluid sample, such as a diluted fluid sample, from another portion of the system 100 (not shown). In implementations, the fluid sample can be sourced from an autosampler of the system 100, however the disclosure is not limited to such configuration. The valve 506 is shown including a mixing port 516 to receive nanoparticle standard solution from fluid line 508 via a selection channel 518 and sample from the sample inlet portion 510 to mix the fluids inline to provide a mixed sample and standard fluid to a nebulizer 520 (e.g., a nebulizer of the analysis system 110). By mixing the sample and the nanoparticle standard solution inline in the valve 506 just prior to transfer for the nebulizer 520, the system 100 provides minimal contact time between the sample and the nanoparticle standard solution prior to analysis by the analysis system 100, which can prevent or otherwise mitigate against chemicals provided in the sample from dissolving or otherwise damaging the nanoparticles in the standard.
The system 100 can also facilitate automated rinsing of fluid flow pathways between drawing and injecting nanoparticle standards to remove trace amounts of nanoparticle standard that might remain adhered to fluid lines, valves, or the like. For example, referring to
Referring to
Electromechanical devices (e.g., electrical motors, servos, actuators, or the like) may be coupled with or embedded within the components of the system 100 to facilitate automated operation via control logic embedded within or externally driving the system 100. The electromechanical devices can be configured to cause movement of devices and fluids according to various procedures, such as the procedures described herein. The system 100 may include or be controlled by a computing system having a processor or other controller configured to execute computer readable program instructions (i.e., the control logic) from a non-transitory carrier medium (e.g., storage medium such as a flash drive, hard disk drive, solid-state disk drive, SD card, optical disk, or the like). The computing system can be connected to various components of the system 100, either by direct connection, or through one or more network connections (e.g., local area networking (LAN), wireless area networking (WAN or WLAN), one or more hub connections (e.g., USB hubs), and so forth). For example, the computing system can be communicatively coupled to the agitator 102, the vacuum loader 300, valves described herein, pumps described herein, other components described herein, components directing control thereof, or combinations thereof. The program instructions, when executed by the processor or other controller, can cause the computing system to control the system 100 (e.g., control pumps, selection valves, actuators, positioning devices, etc.) according to one or more modes of operation, as described herein.
It should be recognized that the various functions, control operations, processing blocks, or steps described throughout the present disclosure may be carried out by any combination of hardware, software, or firmware. In some embodiments, various steps or functions are carried out by one or more of the following: electronic circuitry, logic gates, multiplexers, a programmable logic device, an application-specific integrated circuit (ASIC), a controller/microcontroller, or a computing system. A computing system may include, but is not limited to, a personal computing system, a mobile computing device, mainframe computing system, workstation, image computer, parallel processor, or any other device known in the art. In general, the term “computing system” is broadly defined to encompass any device having one or more processors or other controllers, which execute instructions from a carrier medium.
Program instructions implementing functions, control operations, processing blocks, or steps, such as those manifested by embodiments described herein, may be transmitted over or stored on carrier medium. The carrier medium may be a transmission medium, such as, but not limited to, a wire, cable, or wireless transmission link. The carrier medium may also include a non-transitory signal bearing medium or storage medium such as, but not limited to, a read-only memory, a random access memory, a magnetic or optical disk, a solid-state or flash memory device, or a magnetic tape.
Although the subject matter has been described in language specific to structural features and/or process operations, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.
The present application claims the benefit of 35 U.S.C. § 119(e) of U.S. Provisional Application Ser. No. 63/350,642, filed Jun. 9, 2022, and titled “AUTOMATED INLINE NANOPARTICLE STANDARD MATERIAL ADDITION.” U.S. Provisional Application Ser. No. 63/350,642 is herein incorporated by reference in its entirety.
Number | Date | Country | |
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63350642 | Jun 2022 | US |