Patent Publication Number: US-2009217947-A1

Title: Nebulizer rinse system and method of use

Description:
FIELD OF INVENTION 
     This invention relates to method of clearing potentially interfering residual sample from a nebulizer. 
     BACKGROUND OF INVENTION 
     In many laboratory settings, it is often desired to convert liquid samples into aerosols prior to chemical analysis with a spectrometer or other analytical instrumentation. Such process is often performed by use of a self-aspirating nebulizer. For instance, liquid samples may be introduced into a nebulizer and aspirated into an aerosol. The aerosol may then be transferred from the nebulizer to a device suitable for analyzing the aerosol, such as an inductively coupled plasma mass spectrometry (ICP-MS) spectrometer. When multiple samples are consecutively transported through a nebulizer, particles of a previous sample may remain in the nebulizer, and may cause inaccurate analysis of subsequent samples. 
     Therefore, it would be desirable to provide a system and method for rinsing a nebulizer. 
     SUMMARY OF INVENTION 
     Accordingly, the present invention is directed to a system and method for rinsing a nebulizer. According to a first embodiment, a method for rinsing a nebulizer is disclosed. The method for providing rinsing of a nebulizer includes, but is not limited to: directing a first rinsing liquid through a sample transport line to a sample receiving port of a nebulizer; directing a second rinsing liquid followed by a nebulizing gas to a gas receiving port of the nebulizer through a valve assembly, the valve assembly being connected to a gas transport line configured to transport at least one of the nebulizing gas and the second rinsing liquid to the gas receiving port; rinsing the sample transport line and an interior portion of the nebulizer with the first rinsing liquid; and rinsing an interior portion of the nebulizer with the second rinsing liquid transported through the gas transport line into the interior portion of the nebulizer via the gas receiving port. In addition to the foregoing, other computationally implemented method aspects are described in the claims, drawings, and text forming a part of the present disclosure. 
     According to a second embodiment, a system for rinsing a nebulizer is disclosed. The nebulizer rinsing system includes, but is not limited to: a liquid sample introduction line; a nebulizer, further including a plurality of nebulizer ports, at least one of the nebulizer ports being a sample introduction line receiving port and at least one of the nebulizer ports being a gas receiving port; a valve assembly configured to receive at least one of a nebulizer gas and a rinsing liquid; and a transport line configured to provide transportation of a rinsing liquid through the transport line to the gas receiving port of the nebulizer to rinse an interior portion of the nebulizer. In addition to the foregoing, other computationally implemented method aspects are described in the claims, drawings, and text forming a part of the present disclosure. 
     According to a third embodiment, an additional system for rinsing a nebulizer is disclosed. System includes, but is not limited to: a sample introduction line, a nebulizer further comprising a sample receiving port configured to receive a sample and a gas receiving port configured to receive at least one of a nebulizing gas from a gas source or a first rinsing liquid from a first rinsing liquid reservoir, a valve assembly configured to allow a portion of the gas or the rinsing liquid to flow therethrough; a gas transport line configured to transport at least one of the gas or the first rinsing liquid into an interior portion of the nebulizer through the gas receiving port; and a second rinsing liquid reservoir suitable for providing a second rinsing liquid transportable through the sample introduction line into an interior portion of the nebulizer via the sample receiving port. The sample is nebulized within the nebulizer by applying a nebulizer gas to the sample within the interior portion of the nebulizer, the nebulizer gas being directed into the nebulizer through the gas receiving port from a nebulizer gas source directed through a valve assembly, and the nebulizer is rinsed by directing the first rinsing liquid through the valve assembly to the gas transport line, transporting the first rinsing liquid into the nebulizer through the gas receiving port, and directing the second rinsing liquid through the sample introduction line into the nebulizer through the sample receiving port. In addition to the foregoing, other computationally implemented method aspects are described in the claims, drawings, and text forming a part of the present disclosure. 
     The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       The numerous objects and advantages of the present invention may be better understood by those skilled in the art by reference to the accompanying figures in which: 
         FIG. 1  illustrates an operational flow representing example operations related to providing a method for rinsing a nebulizer; 
         FIG. 2  illustrates an alternative embodiment of the operational flow of  FIG. 1 . 
         FIG. 3  illustrates an alternative embodiment of the operational flow of  FIG. 1 . 
         FIG. 4  illustrates an alternative embodiment of the operational flow of  FIG. 1 . 
         FIG. 5  illustrates an alternative embodiment of the operational flow of  FIG. 1 . 
         FIG. 6  is a schematic illustration of a system for development of a nebulized sample; 
         FIG. 7A  is a detailed schematic illustration of a first embodiment of a system for development of a nebulized sample in analysis mode according to an exemplary embodiment of the invention; 
         FIG. 7B  is a detailed schematic illustration of a first embodiment of a system for development of a nebulized sample in rinse mode according to an exemplary embodiment of the invention; 
         FIG. 8A  is a detailed schematic illustration of a second embodiment of a system for development of a nebulized sample in analysis mode according to an exemplary embodiment of the invention; 
         FIG. 8B  is a detailed schematic illustration of a second embodiment of a system for development of a nebulized sample in rinse mode according to an exemplary embodiment of the invention; 
         FIGS. 9A-9E  are graphical illustrations of subsequent samples run through a conventional system plotted as the on-line intensity for Thorium on a logarithmic scale; 
         FIGS. 10A-10E  are graphical illustrations of subsequent samples run through a system according to an exemplary embodiment of the invention plotted as the on-line intensity for Thorium on a logarithmic scale; 
         FIG. 11A  is a detailed schematic illustration of a third embodiment of a system for development of a nebulized sample in analysis mode according to an exemplary embodiment of the invention; and 
         FIG. 11B  is a detailed schematic illustration of a third embodiment of a system for development of a nebulized sample in rinse mode according to an exemplary embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION OF INVENTION 
     Reference will now be made in detail to the presently preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. 
     Referring to  FIG. 1 , an operational flow  100  representing example operations related to providing a method for rinsing a nebulizer according to an embodiment of the invention is illustrated. In  FIG. 1  and in following figures that include various examples of operational flows, discussion and explanation may be provided with respect to the below-described examples of  FIGS. 6-11  and/or with respect to other examples and contexts. However, it should be understood that the operational flows may be executed in a number of other environments and contexts, and/or in modified versions of  FIGS. 6-11 . Also, although the various operational flows are presented in the sequence(s) illustrated, it should be understood that the various operations may be performed in other orders than those which are illustrated, or may be performed concurrently. 
     Method  100  begins at an operation  102 . Operation  102  depicts directing a first rinsing liquid through a sample transport line to a sample receiving port of a nebulizer. Operation  104  depicts directing a second rinsing liquid followed by a nebulizing gas to a gas receiving port of the nebulizer through a valve assembly, the valve assembly being connected to a gas transport line configured to transport at least one of the nebulizing gas and the second rinsing liquid to the gas receiving port. Operation  106  depicts rinsing the sample transport line and an interior portion of the nebulizer with the first rinsing liquid. Operation  108  depicts rinsing an interior portion of the nebulizer with the second rinsing liquid transported through the gas transport line into the interior portion of the nebulizer via the gas receiving port. 
       FIG. 2  illustrates alternative embodiments of the example operational flow  100  of  FIG. 1 .  FIG. 2  illustrates example embodiments where the operation  102  may include at least one additional operation. Additional operations may include an operation  202 , an operation  204 , and/or an operation  206 . Operation  202  illustrates directing a first rinsing liquid through a sample transport line to a sample receiving port of a nebulizer formed from a hydrophobic material suitable for preventing droplet breaking. Operation  204  illustrates directing a first rinsing liquid through a sample transport line to a sample receiving port of a nebulizer formed from a hydrophilic material. Operation  206  depicts directing an acid or a base rinsing liquid into an interior portion of the nebulizer through the sample receiving port. 
       FIG. 3  illustrates alternative embodiments of the example operational flow  100  of  FIG. 1 .  FIG. 3  illustrates example embodiments where the operation  104  may include at least one additional operation. Additional operations may include an operation  302  and/or operation  304 . Operation  302  illustrates electronically controlling the valve assembly to introduce the rinsing liquid through the gas port. Operation  304  illustrates manually controlling the valve assembly to introduce the rinsing liquid through the gas port. 
       FIG. 4  illustrates alternative embodiments of the example operational flow  100  of  FIG. 1 .  FIG. 4  illustrates example embodiments where the operation  102  may include at least one additional operation. Additional operations may include an operation  402  and/or operation  404 . Operation  402  illustrates utilizing the nebulizing gas to push the second rinsing liquid through a loop assembly disposed within the valve assembly and through the gas transport line. Operation  404  illustrates utilizing a pump to pump the second rinsing liquid through a loop assembly disposed within the valve assembly and through the gas transport line. 
       FIG. 5  illustrates alternative embodiments of the example operational flow  100  of  FIG. 1 .  FIG. 5  illustrates example embodiments where the operation  104  may include at least one additional operation. Additional operations may include an operation  502  and/or operation  504 . Operation  502  illustrates directing an acid or a base rinsing liquid into an interior portion of the nebulizer through the gas receiving port. Operation  504  illustrates directing a second rinsing liquid followed by a nebulizing gas to a gas receiving port of the nebulizer through a valve assembly that is at least one of a three-way valve assembly, a linear valve assembly, or a rotatable valve assembly. 
     Referring to  FIG. 6 , a schematic illustration of a system  600  for development of a nebulized sample, a detailed schematic illustration of a system  600  for development of a nebulized sample of a liquid for analysis in analysis mode according to an exemplary embodiment of the invention, and a detailed schematic illustration of a system  600  for development of a nebulized sample in rinse mode according to an exemplary embodiment of the invention are shown. System  600  may comprise a liquid sample introduction line  602 , and a nebulizer  604 . The nebulizer may further include an interior nebulizer portion  606  and a plurality of nebulizer ports  608 ,  610 . At least one of the nebulizer ports may be a liquid sample receiving port  608  and at least one of the nebulizer ports may be a gas receiving port  610 . System may also comprise a sample reservoir  612 , a gas transport line  614  and a gas source  616 . The liquid sample introduction line  602  may transport a sample from a sample reservoir  612  to the nebulizer  604  via the liquid sample receiving port  608  and the gas transport line  614  may transfer a gas from a gas source  616  to the nebulizer via the gas receiving port  610 . 
     Referring to  FIGS. 7A and 7B , detailed schematic illustrations of a first embodiment of a system  700  for development of a nebulized sample are shown. Specifically,  FIG. 7A  is a detailed schematic illustration of a first embodiment of a system  700  for development of a nebulized sample in analysis mode according to an exemplary embodiment of the invention, and  FIG. 7B  is a detailed schematic illustration of a first embodiment of a system  700  for development of a nebulized sample in rinse mode according to an exemplary embodiment of the invention. System  700  may comprise a liquid sample introduction line  602 , and a nebulizer  604 . The nebulizer  604  may further include an interior nebulizer portion  606  and a plurality of nebulizer ports  608 ,  610 . At least one of the nebulizer ports  608 ,  610  may be a liquid sample receiving port  608 , and at least one of the nebulizer ports may be a gas receiving port  610 . System  700  may also comprise a sample reservoir  612 , a gas transport line  614  and a gas source  616 . The liquid sample introduction line  602  may transport a sample from a sample reservoir  612  to the nebulizer  604  via the liquid sample receiving port  608  and the gas transport line  614  may transfer a gas from a gas source  616  to the nebulizer  604  via the gas receiving port  610 . Liquid sample receiving port  608  may direct a sample into the interior nebulizer portion  606 , and the gas receiving port  610  may direct a gas into the interior nebulizer portion  606 . In operation, a sample to be analyzed may be pumped by a pump  1102  (shown in  FIG. 11 ) from source  612  to nebulizer  604  and gas may be directed by a regulator from a gas source  616  so that the aerosolized sample  618  may be ejected from nebulizer  604  into a spray chamber (not shown) where the aerosol may pass through a chamber outlet or a sample exit port of the chamber (not shown). 
     System  700  may also comprise a rinsing liquid reservoir  702  containing a rinsing liquid, a rinsing liquid transport line  704 , and a valve assembly  706  configured to receive a nebulizer gas from a gas source  616  and a rinsing liquid from the rinsing liquid reservoir  704 . Rinsing liquid may be a saline solution, an acid solution, or any solution suitable for rinsing the interior nebulizer portion  606 . In the configuration described by  FIGS. 7A and 7B , transport line  614  may be connected to the valve assembly  706  and to the gas receiving port  610 . The gas transport line  614  is configured to provide transportation of a rinsing liquid through the gas transport line  614  to the gas receiving port  610  of the nebulizer  604  to rinse the interior nebulizer portion  606 . The gas transport line  614  may alternately or simultaneously deliver gas from a gas source  616  and a rinsing liquid from a rinsing liquid reservoir  702  to the nebulizer  604 . System  700  may further include an overflow transport line  710  and an overflow container  712  to collect any overflow rinsing liquid. Valve assembly  706  may further comprise at least one loop assembly  714  and a plurality of openable/closeable ports  708  configured to open and/or close to allow a gas, a rinsing liquid and/or a combination of a gas and a rinsing liquid to flow through the loop assembly  714  to the gas transport line or the overflow transport line  710  via port tubing connecting one or more ports together and/or to the loop assembly  714 . Prior to introducing a subsequent sample into a spray chamber and/or a device for analysis, a solution  718  comprising the rinsing liquid and any residual amounts of the aerosolized sample which could contaminate the subsequent sample aerosol and provide erroneous analysis results, may be removed at least to a background level of the analysis. 
     As described above, valve assembly  706  may comprise a plurality of channel connected ports  708 , and at least one loop assembly  714  configured to selectively receive at least one of a gas or a rinsing liquid. Valve assembly  706  may be moveable to a desired configuration. In one embodiment, valve assembly  706  is rotatable. Valve assembly  706  may also be a linear valve assembly, a three way valve assembly (as shown in  FIG. 11 ), or any other mechanism for allowing a determined amount of at least one of a gas or liquid to pass through to a transport line such as the gas transport line  614  of  FIGS. 6-8B  and  11 . For instance, loop assembly  714  may be configured in a first configuration allowing only a gas from a gas source  616  to be transported to the valve assembly  708 . Valve assembly  708  may allow the gas to be transported from a port connected to the gas transport line  614  to the gas receiving port  610  of the nebulizer  604 , as shown in  FIG. 7A . Loop assembly  714  may be configured in further additional configurations allowing rinsing liquid to be transported through the loop assembly  714  to gas transport line  614 , as shown in  FIG. 7B . For instance, the valve assembly  706  may be configured in the second configuration and a rinsing liquid may be pumped from the rinsing liquid reservoir  702  by pump into the valve assembly  706  to fill the loop assembly  714 . When loop assembly  714  is filled, valve assembly  706  may shift to a third configuration to allow the rinsing liquid to flow from the loop assembly  714  to a valve assembly port connected to the gas transport line  614 . Loop assembly  714  may be further configured to allow a gas and a rinsing liquid to be transported through the loop assembly  714  to the gas transport line  614 . Transport of gas, rinsing liquid or both through a loop assembly  714  may be accomplished without the development of an air bubble between individual substances or solutions as they are transported through the loop assembly  714 . Transport of rinsing liquid through a loop assembly  714  may be accomplished by pushing gas from the gas source  616  behind an injection of rinsing liquid or pumping the rinsing liquid through the loop assembly  714  with a pump (as shown in  FIG. 11 ). 
     When the valve is configured in analysis mode, as shown in  FIG. 7A , the rinsing liquid from the rinsing liquid reservoir  712  may fill the loop assembly  714  and be directed to a valve assembly port connected to an overflow transport line  710  to transport the rinsing liquid to the overflow container  712 . In an additional embodiment, the rinsing liquid may be transported through the loop assembly  714  and transported to a valve assembly opening connected to tubing configured to return the rinsing liquid to the rinsing liquid reservoir. If required, a valve assembly port may be positioned to allow gas under pressure from gas source  616  to force the rinsing liquid through the loop assembly  714  and to a valve assembly port connected to the gas transport line  614 . 
     System  700  may further comprise a control assembly  716  for controlling the valve assembly  706 . Control assembly  716  may provide periodic or intermittent introduction of the rinsing liquid into the interior portion of the nebulizer via the gas receiving port connected to the gas transport line. In one embodiment, the control assembly  716  is a general purpose computer system programmed to receive signal information from the detector and to control operation of the detector. In this embodiment, control assembly  716  has a conventional display, such as a cathode ray tube or a liquid crystal display monitor. The control assembly  716  also has user input mechanisms, such as a keyboard and mouse. In an embodiment, a touch screen user interface is used. In other embodiments, the valve assembly  706  may be manually operated/controlled. 
     Referring to  FIGS. 8A and 8B , detailed schematic illustrations of an additional system  800  for development of a nebulized sample are shown. Specifically,  FIG. 8A  is a detailed schematic illustration of a second embodiment of a system for development of a nebulized sample in analysis mode according to an exemplary embodiment of the invention, and  FIG. 8B  is a detailed schematic illustration of a second embodiment of a system for development of a nebulized sample. System  800  may comprise a sample introduction line  602 , and a nebulizer  604  further comprising a sample receiving port  608  configured to receive a sample and a gas receiving port  610  configured to receive at least one of a nebulizing gas or a rinsing liquid, a valve assembly  706  configured to allow a portion of the gas and/or the rinsing liquid to flow therethrough, a control assembly  716  for controlling the valve assembly  706 , a gas transport line  614  configured to transport one of the gas or the rinsing liquid to the gas receiving port and a second rinsing liquid reservoir  802  suitable for transporting a second rinsing liquid through the sample introduction line  602  into the nebulizer  604 . The sample is nebulized within the nebulizer by applying a nebulizer gas to the sample within the nebulizer, the nebulizer gas being directed into the nebulizer through the gas receiving port from a nebulizer gas source  614  directed through a valve assembly  706 , the valve assembly  706  configured to allow a portion of the nebulizer gas from the nebulizer gas source to flow therethrough, and the nebulizer is rinsed by directing a first rinsing liquid through valve assembly  706  to the gas transport line  614  and a second rinsing liquid through the sample introduction line to the sample receiving port. First and second rinsing liquids may be the composed of the same rinsing solution or may be composed of different solutions as required/desired by a system and/or an operator. First and second rinsing liquids may be acids, bases or any combination of liquids. System  800  may be configured in a manner similar to system  700 , with the addition of the second rinsing liquid reservoir  802  and pump  1106  (shown in  FIG. 11 ) configured to pump a second rinsing liquid through the sample introduction line  602 . Prior to introducing a subsequent sample into a spray chamber and/or a device for analysis, a solution  804  that is a combination of the first and second rinsing liquids, along residual amounts of the aerosolized sample which could contaminate the subsequent sample aerosol and provide erroneous analysis results, may be removed at least to a background level of the analysis. 
     Referring to  FIGS. 11A and 11B , a system  1100  for rinsing a nebulizer is shown.  FIG. 11A  is a detailed schematic illustration of a third embodiment of a system for development of a nebulized sample in analysis mode according to an exemplary embodiment of the invention.  FIG. 11B  is a detailed schematic illustration of a third embodiment of a system for development of a nebulized sample in rinse mode according to an exemplary embodiment of the invention. System  1100  may include a sample transport line  602  coupled to a sample reservoir  612  and at least one pump  1102  operable to pump a first rinsing liquid from a first rinsing liquid reservoir  802  (shown in  FIG. 11B ) through the sample transport line  602 , a nebulizer  604  further including an interior portion  606 , a sample receiving port  608 , a gas receiving port  610 , a gas transport line  614  coupled to a three-way valve assembly  1104 . Three way valve assembly  1104  may comprise inputs for receiving a gas transport line  614  and a rinsing liquid transport line  706  coupled with a second pump  1106  operable to pump a rinsing liquid to from a rinsing liquid source  702  to the nebulizer  604  (i.e., into interior portion of the nebulizer  606 ). In operation, a sample to be analyzed may be pumped by pump  1104  from source  612  to nebulizer  604  and gas is passed by a regulator from a gas source  616  so that the combination of the first rinsing liquid and the second rinsing liquid  718  may be ejected from nebulizer  604  into a spray chamber (not shown) where the aerosol may pass through a chamber outlet or a sample exit port of the chamber. 
     In one embodiment, the nebulizer  604  is a pneumatic nebulizer constructed from PFA Teflon™, such as the nebulizers available from Elemental Scientific, Inc. of Omaha, Nebr. In one embodiment, the sample introduction line  602 , the gas transport line  614 , and the rinsing liquid transport line  704  are constructed from a hydrophobic material suitable for preventing droplet breaking, such as PFA Teflon material. The liquid sample introduction line  602 , the gas transport line  614 , and the rinsing liquid transport line  704  may be any diameter or length suitable for delivery of a sample, gas or rinsing liquid as necessary. In alternative embodiments, the liquid sample introduction line  602 , the gas transport line  614 , and the rinsing liquid transport line  704  may include an anti-static exterior sheath, such as a carbon filled polymer sheath. It is understood that other anti-static mechanisms can be employed to dissipate static electrical charges in the vie departing from the teachings of the present invention, such as anti-static air shower systems. At least a portion of the nebulizer may also be hydrophilic, and/or formed from glass or any other material suitable for constructing a nebulizer. 
       FIGS. 9A-9E  are graphical illustrations of subsequent samples run through a conventional system plotted as the on-line intensity for Thorium on a logarithmic scale. After 5 injection runs, large increases in signal spikes due to the reaspirated sample are seen when utilizing a conventional rinse method.  FIGS. 10A-10E  are graphical illustrations of subsequent samples run through a nebulizer having system  700  according to exemplary embodiments of the invention plotted as the on-line intensity for Thorium on a logarithmic scale. The signal levels averaged zero during every run, with no build up of reaspirated sample causing undesireable spiking. 
     It is believed that the present invention and many of its attendant advantages will be understood by the foregoing description. It is also believed that it will be apparent that various changes may be made in size, materials, shape, form, function, manner of operation, assembly and use of the components thereof without departing from the scope and spirit of the invention or without sacrificing all of its material advantages. The form herein before described being merely an explanatory embodiment thereof. Further, it is contemplated that the specific order or hierarchy of steps in the method can be rearranged while remaining within the scope and spirit of the present invention. It is the intention of the following claims to encompass and include such changes.