Abstract:
An apparatus and method for automatedly detecting the presence of one or more chemical contaminants, such as 2,4,6-trichloroanisole, in/on a plurality of cork wine bottle stoppers in rapid succession using electronic nose chips. The apparatus moves the nose chips and the cork stoppers independently to align the cork stopper and a corresponding electronic nose chip with one another for testing. The automated apparatus and method provides a low-cost, reliable process for testing 100% of cork wine bottle stoppers in a fast and cost-effective manner.

Description:
RELATED APPLICATION DATA  
       [0001]     This application is a continuation of U.S. patent application Ser. No. 10/701,715, filed Nov. 5, 2003, and titled “APPARATUS AND METHOD FOR DETECTING AN ANALYTE,” now U.S. Pat. No. 7,010,956, which is incorporated by reference herein in its entirety. 
     
    
     FIELD OF THE INVENTION  
       [0002]     The present invention generally relates to the field of wine bottling and, more particularly, to an automated apparatus and method for testing cork wine bottle stoppers for the presence of an analyte that causes cork taint in bottled wine.  
       BACKGROUND OF THE INVENTION  
       [0003]     The wine industry produces approximately fourteen billion bottles of wine per year. The bottled wines range in price from inexpensive table wines to very expensive, high-quality wines. The more expensive wines (i.e., from fifty dollars to thousands of dollars per bottle) are typically produced by a small number (presently, about two thousand) of high-end wineries that produce 200,000 to 80 million bottles of wine each per year.  
         [0004]     Most bottled wines, both inexpensive and expensive, are sealed with cork stoppers. Cork stoppers include natural cork stoppers punched from strips of bark and less expensive molded or extruded agglomerated cork with natural cork discs on each end. Wine makers generally prefer cork stoppers for sealing their bottles to maintain the traditional wine-opening experience that consumers expect. Unfortunately, the use of cork stoppers can adversely affect the taste of wine, a characteristic commonly referred to as “cork taint.” Cork taint describes the “off” smell and taste imparted to wine from chemical contaminants such as 2,4,6-trichloroanisole (TCA) in the cork stopper.  
         [0005]     The incidence of cork taint is sporadic and random, typically affecting 1-2% of bottled wines. Since cork taint takes effect after bottling, it cannot be detected until after a bottle has been opened. Cork taint manifests as very undesirable aroma and flavor characters that are imparted to bottled wines following contact with the cork. There is nothing more offensive and embarrassing for wine consumers and producers alike than for their wine to be rated as “spoiled.” For consumers, opening a cork-tainted bottle of wine can be socially embarrassing, particularly if it is an expensive bottle of wine. For wine collectors, the 1-2% incidence of cork taint imparts uncertainty about the entire wine collection. For producers, cork-tainted wine can damage their reputation, causing consumers to question the integrity and quality of their wine. Thus, there exists a need for a means to ensure the quality of cork stoppers used to bottle wines.  
         [0006]     The chemical compound contributing most significantly to cork taint is TCA, which is implicated in more than 80% of cork-tainted wines. The production of TCA is the result of complex chemical mechanisms, including the conversion of chlorophenols to chloroanisole by common microorganisms, such as fungi, in the presence of moisture. Chlorophenols are typically used as pesticides and wood preservatives, and, consequently, they are common environmental pollutants. The uptake of even minute amounts of chlorophenol by the bark of a cork tree at any stage during its growth can yield corks that will produce cork taint in wine. Alternatively, cork taint can be the result of interaction between naturally occurring fungi in the tree bark and chlorine, a chemical commonly used to sanitize the cork. Cork, like any other wine input, therefore demands exhaustive quality control.  
         [0007]     Quality assurance at every step of the cork stopper manufacturing process is a major concern of the cork industry. This concern has led to the implementation of the “International Code of Cork Stoppers Manufacturing Practices.” The code establishes quality-control standards throughout the production process and aims to provide guarantees to cork suppliers, wine producers, and bottlers that they have a product that is free from contamination.  
         [0008]     In addition, premium cork suppliers also insist on rigorous quality-control testing of their cork stoppers for TCA. Current industry practices for quality-control testing of cork stoppers include sensory-based methods (i.e., olfactory detection or human experts) and chemical analysis (e.g., cork soaks and gas chromatography/mass spectroscopy). However, these testing procedures are limited to testing batches of cork stoppers (e.g., statistical sampling). For example, for every 100 million or more cork stoppers produced, only a half-million to one million are tested for TCA. The batch sampling approach does not eliminate the possibility that a TCA-tainted cork will be undetected during quality-control testing and subsequently used by a wine producer or bottler. Thus, there exists a need for a testing process that provides 100% testing of cork stoppers for TCA prior to bottling.  
         [0009]     Another limitation of current testing methods is that they are expensive and time consuming. Further, sensory-based methods that rely on human experts are subjective, variable and exhaustible. Thus, there exists a need for a low-cost, reliable testing process that provides 100% testing of cork stoppers for TCA prior to bottling.  
         [0010]     The wine industry, seeking to increase consistency and consumer loyalty, has investigated alternative quality-control procedures. One alternative is the application of electronic nose technology to quality-control testing at all stages of wine production, e.g., bottling. An electronic nose is a sensing device capable of producing a fingerprint of specific odors. Current technology includes electronic noses that use odor-reactive polymer sensor arrays and a pattern-recognition system (i.e., e-Nose) and gas chromatography coupled to surface acoustic wave sensors (i.e., z-Nose). In one example of polymer sensor arrays, the electronic nose uses a one-inch-square microelectrical mechanical systems (MEMS) chip containing 32 pinhead-sized receptors forming a sensor array. The receptors are constructed from a conductive carbon black material blended with specific nonconductive polymers (manufactured by Cyrano Sciences, Inc., Pasadena, Calif.). When the MEMS chip is exposed to a specific vapor, a corresponding receptor expands, temporarily breaking some of the connections between the carbon black pathways and thereby increasing the electrical resistance in the sensor. Signals from the sensors are electronically processed by a microprocessor that interprets the data by using the pattern-recognition system to identify and/or quantify a specific odor contained in the vapor.  
         [0011]     Application of electronic nose technology to quality-control monitoring of agricultural products is exemplified in U.S. Pat. No. 6,450,008 to Sunshine et al., entitled, “Food applications of artificial olfactometry.” The Sunshine et al. patent describes a method and device for evaluating agriculture products and, more particularly, for assessing and monitoring the quality of food products by using electronic noses. The quality control monitoring device includes two sensor arrays for comparative monitoring of an agricultural product, e.g., before and after a processing step such as blending or mixing, or detection of a contaminant (e.g., microorganism) relative to a clean sample. However, the quality-control monitoring device is a single device that typically requires up to three minutes to obtain a result and to cycle to the next measurement, thus limiting the number of measurements that can be determined by a single device. Further, the existing devices are expensive, which precludes purchasing multiple instruments to achieve 100% testing of a product in a production process. Thus, there exists a need for a means to test 100% of all corks in a fast and cost-efficient way.  
         [0012]     The introduction of a new technology platform (e.g., electronic nose technology) into an existing industry (e.g., the wine industry) is often a difficult and expensive process. Often, a new technology platform is implemented by high-end or specialty producers (e.g., high-end wine producers), for which the costs associated with the production of a quality product are generally higher and the benefits provided by the new technology are initially greater. However, this approach neglects the general consumer market (e.g., inexpensive table wines), in which the volume of products consumed offers greater potential returns. Thus, there exists a need for a means to test 100% of all corks at production speed that is cost-efficient and scalable to the general consumer market.  
       SUMMARY OF THE INVENTION  
       [0013]     In one aspect, the present invention is directed to a method of testing a plurality of cork wine bottle stoppers for the presence of an analyte known to cause cork taint in wine. The method comprises automatedly moving a first one of the plurality of cork wine bottle stoppers to a first position. A first sensor is automatedly moved to a second position proximate the first position. The first sensor is operatively configured to detect the presence of the analyte. It is determined via the first sensor whether the analyte is present in/on the first one of the plurality of cork wine bottle stoppers. The first one of the plurality of cork wine bottle stoppers is automatedly moved out of the first position. The first sensor is automatedly moved out of the second position. A second one of the plurality of cork wine bottle stoppers is automatedly moved into the first position. A second sensor is automatedly moved to the second position. The second sensor is operatively configured to detect the presence of the analyte. It is determined via the second sensor whether the analyte is present in/on the second one of the plurality of cork wine bottle stoppers.  
         [0014]     In another aspect, the present invention is directed to a method of testing cork wine bottle stoppers for the presence of an analyte known to cause cork taint in wine. The method comprises providing at least 100 candidate cork wine bottle stoppers. The at least 100 candidate cork wine bottle stoppers are fed into an automated testing system comprising a plurality of electronic noses sensitive to the analyte. The automated testing system is caused to test each of the at least 100 candidate cork wine bottle stoppers for the presence of the analyte in rapid succession with others of the at least 100 candidate cork wine bottle stoppers using the plurality of electronic noses and to separate the at least 100 candidate cork wine bottle stoppers into an accepted set and a rejected set.  
         [0015]     In yet another aspect, the present invention is directed to a cork sorting apparatus comprising a plurality of electronic noses each operatively configured to detect a chemical contaminant known to cause cork taint in wine. A stopper conveying system is operatively configured to hold and move each cork wine bottle stopper of a plurality of cork wine bottle stoppers in rapid succession to a first position. An electronic nose system is operatively configured to move each electronic nose of the plurality of electronic noses, in seriatim, to a second position proximate the first position in concert with the first system. Sensor electronics are operatively configured to identify from within the plurality of cork wine bottle stoppers via the plurality of electronic noses accepted cork wine bottle stoppers and rejected cork wine bottle stoppers. A sorting system is operatively configured to separate the rejected cork wine bottle stoppers from the accepted cork wine bottle stoppers. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0016]     For the purpose of illustrating the invention, the drawings show a form of the invention that is presently preferred. However, it should be understood that the present invention is not limited to the precise arrangements and instrumentalities shown in the drawings, wherein:  
         [0017]      FIG. 1  is a perspective view of a testing apparatus of the present invention for detecting the presence of an analyte;  
         [0018]      FIG. 2  is a high-level schematic diagram of a system of the present invention for operating the testing apparatus of  FIG. 1 ;  
         [0019]      FIG. 3A  is an enlarged perspective view of one of the sensor units of the testing apparatus of  FIG. 1 ;  
         [0020]      FIG. 3B  is a high-level schematic diagram of the sensor electronics of the testing apparatus of  FIG. 1 ; and  
         [0021]      FIG. 4  is a flow diagram of a method of using the testing apparatus of  FIG. 1  to detect the presence of an analyte in a plurality of items, wherein the items are cork stoppers. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0022]     Generally, the present invention is an apparatus and method for detecting an analyte and, more particularly, assessing and monitoring items, such as cork stoppers, for the presence of one or more chemical contaminants or other analytes using electronic noses or other sensors. In one embodiment, the invention uses sensors and detection sensor electronics that are separate from one another such that inexpensive sensors may be reused or discarded with a rejected item. The testing apparatus moves the sensors and items independently to align a sensor and item with a detection sensor unit and/or move each sensor into electrical contact with the detection sensor electronics.  
         [0023]     The testing apparatus may utilize multiple sensor units to simultaneously test multiple items (e.g., cork stoppers) for a chemical contaminant (e.g., TCA). The invention provides a low-cost, reliable testing process for testing up to 100% of the items at production speed in a cost-effective way that is scalable to the general consumer market. Although the present invention is particularly described in connection with testing bottle stoppers made of cork for the presence of a particular analyte, those skilled in the art will readily appreciate that the invention can be adapted for testing virtually any type of item made of any type of material for the presence of one or more of a wide variety of analytes susceptible to detection by various sensors.  
         [0024]     Referring now to the drawings,  FIG. 1  shows in accordance with the present invention a testing apparatus, which is generally denoted by the numeral  100 . As mentioned, apparatus  100  may be adapted for testing virtually any items, but in the present example items are cork stoppers  110 . Apparatus  100  may include, among other things, a hopper/dispenser  105 , a plurality of receivers  115  (e.g., receivers  115   a,    115   b,    115   c,    115   d  and  115   e ), a web  120 , a plurality of partitions  125 , a plurality of air movers  130  (e.g., air movers  130   a,    130   b,  and  130   c ), a plurality of sensor units  135  (e.g., sensor units  135   a,    135   b,  and  135   c ), a diverter  145 , a plurality of rollers  150  (e.g., rollers  150   a,    150   b,    150   c,  and  150   d ), a recess  155 , an accept bin  160  and a reject bin  165 .  
         [0025]     Hopper/dispenser  105  is a storing and dispensing device for stoppers  110  to be tested. Hopper  105  may be suspended over web  120  and controlled such that a single stopper  110  is dispensed into each receiver  115 . In alternative embodiments, hopper/dispenser  105  may be replaced with another device or mechanism, e.g., a conveyor or gated chute, that provides the same functionality of storing and/or delivering stoppers  110  to web  120  or other means for moving stoppers  110 .  
         [0026]     Receivers  115  may be formed in web  120  such that they are open receptacles for stoppers  110 . The top opening of each such receiver  115  should be sufficiently large to receive one of stoppers  110 . Depending upon the location of sensor units  135  relative to web  120 , e.g., above or below, receiver  115  may include a bottom opening (not shown) that allows air to flow through the web. The bottom opening of each receiver  115  should be of sufficient size to retain stopper  110  on web  120  and provide sufficient airflow through web  120  to enable the detection of the analyte(s), if present, at sensor units  135 . Each stopper  110  may be helped into its proper position within receivers  115  by corresponding partitions  125  that provide a physical barrier between adjacent receivers.  
         [0027]     Web  120  may be a continuous belt that is positioned around rollers  150  and formed of any suitable material, such as polyurethane or rubber that provides a sturdy, flexible support for stoppers  110 . Web  120  may be advanced, e.g., in a clockwise rotation, by rollers  150  or another means, not shown. Rollers  150  may be formed of any suitable material such as rubber or metal and may further include a recess  155  that facilitates passage of receivers  115  as web  120  is advanced. Of course, many alternatives to web  120  and rollers  150  exist for moving stoppers  110  into their testing positions proximate corresponding sensor units  135 . Such alternatives include other types of linear conveyors and rotational moving devices, among others. In other alternative embodiments, stoppers  110  may be fed to each sensor unit  135  by a feeder system dedicated to that sensor unit.  
         [0028]     Sensor units  135  may be located in close proximity to receivers  115 , e.g., directly below the upper horizontal portion of web  120 . Of course, in other embodiments of apparatus  100 , sensor units  135  may be located in other suitable locations where testing can be effected, such as laterally adjacent to or above receivers  115 . Details and description of sensor units  135  are discussed below in connection with  FIG. 3A .  
         [0029]     Air movers  130  may by conventional air-moving devices that provide a flow of air over stoppers  110  in receivers  115  and to sensor units  135 . In the embodiment shown, air movers  130  are blowers located opposite corresponding sensor units  135  relative to corresponding receivers  115 . However, air movers  130  may be suction/blower devices located between corresponding receivers  115  and sensor units  130  or opposite the receivers relative to the sensor units. The airflow provided by air movers  130  is any airflow suitable to extract chemical vapors from stoppers  110 . For example, air movers  130  may be adapted to provide treated air, such as heated or pressurized air or nitrogen (N 2 ), and/or to facilitate removal of chemical vapors from stoppers  110  in receivers  115 . Depending upon factors such as the volatility and dispersion properties and amount(s) of the analyte(s) at issue and the proximity and sensitivity of sensor units  135 , air movers may not be required.  
         [0030]     Diverter  145  may be provided to divert one or more contaminated stoppers  110  at a time from web  120  to prevent the rejected stoppers from being processed further along with the non-rejected, or “good,” stoppers. Diverter  145  may be any suitable device, such as a movable arm, and may divert the rejected ones of stoppers  110  to any suitable container, e.g., reject bin  165 , or location, e.g., a reject conveyor (not shown). Reject bin  165 , if provided, may be any suitable collection container that functions to hold rejected stoppers  110  (e.g., those determined to be contaminated with TCA). Similarly, accept bin, if provided, may be any suitable collection container that functions to hold accepted stoppers  110  (e.g., those determined to be not contaminated with TCA).  
         [0031]      FIG. 2  is a high-level block diagram of a control system  200  for operating apparatus  100  of  FIG. 1 . In one embodiment, control system  200  may include a computer  205 , a communication link  210 , a sensor system  215  and a conveyor controller  220 . Computer  205  may be any special-purpose or general-purpose computer, such as a desktop, laptop, or host computer having a processor, memory and storage (not shown) sufficient to run software applications for operating apparatus  100 .  
         [0032]     Sensor system  215  may include a plurality of sensor electronics  225  (e.g., sensor electronics  225   a,    225   b  and  225   n,  where n indicates the corresponding sensor unit  135  in apparatus  100 ). Sensor electronics  225  includes the electronic circuitry, such as a power regulator, processor, memory and storage, sufficient to interface sensor system  215  to computer  205  so as to operate sensor units  135  of apparatus  100 . Sensor electronics  225  may further include the necessary circuitry, such as power regulator, processor, memory and storage, sufficient to run software applications (e.g., pattern signal handling capability and sensor pattern recognition algorithms) for sensor units  135  as described in more detail in reference to  FIG. 3B . Such sensor electronics  225  can be readily designed by a person having ordinary skill in the art such that a detailed explanation of the sensor electronics is not necessary for those skilled in the art to understand and practice the present invention.  
         [0033]     Conveyor controller  220  may include sub-controllers, e.g., a hopper/dispenser controller  230 , a web controller  240 , an air mover controller  250 , a diverter controller  260  and a bin-full controller  270 , to run the corresponding components of apparatus  100 . Hopper/dispenser controller  230  may include software algorithms to control the mechanical operation of hopper/dispenser  105  of apparatus  100 . For example, hopper/dispenser controller  230  may control the dispensing of stoppers  110  into receivers  115 . Web controller  240  may include software algorithms to control the mechanical operation of web  120  of apparatus  100 . For example, web controller  240  may control the rotation of rollers  150  to advance web  120 .  
         [0034]     Air mover controller  250  may include software algorithms to control the mechanical operation of air mover  130  of apparatus  100 . For example, air mover controller  250  may control the flow of heated air from air movers  130  over stoppers  110  in receivers  115  and onto sensor units  135 . Diverter controller  260  may include software algorithms to control the mechanical operation of diverter  145  of apparatus  100 . Diverter controller  260  may be electrically connected to sensor units  135 .  
         [0035]     Bin-full controller  270  may include software algorithms to control the mechanical operations of accept bin  160  and reject bin  165  of apparatus  100 . For example, bin full controller  270  may monitor the levels of stoppers  110  in accept bin  160  and reject bin  165  and indicate to computer  205  when accept bin  160  or reject bin  165  needs to be emptied.  
         [0036]     Conveyor controller  220  and sensor system  215  may communicate with computer  205  via communication link  210 , which may be any suitable wired or wireless communications link. For example, communication link  210  may be a universal serial bus (USB) and may transmit data bi-directionally between computer  205  and sensor system  215 , and between computer  205  and conveyor controller  220 . Alternatively, communication link  210  may be a wireless link, such as an infrared or radio frequency link, among others.  
         [0037]      FIG. 3A  shows one of sensor units  135 . The others of sensor units  135  may be identical to the sensor unit shown for parallel testing of multiple stoppers  110  for the presence of the same analyte. However, the others of sensor units, if provided, may be different from the sensor unit shown. For example, one or more of the other sensor units  135  may be configured for different types of sensors for sensing other types of analytes. Each sensor unit  135  may include sensor electronics  225 , a plurality of nose chips  310  (only one being shown) or other sensors, a plurality of nose chip holders  315  (e.g., holders  315   a,    315   b,    315   c,    315   d ) a web  320 , a plurality of rollers  325  (e.g., rollers  325   a  and  325   b ), and a plurality of probe fingers  330  (e.g., probe fingers  330   a,    330   b  and  330   n,  where n corresponds to the number of probe fingers needed to make nose chips  310  test-functional). Probe fingers  330  are in electrical communication with sensor electronics  225 .  
         [0038]     Each nose chip  310  may include a plurality of sensor elements  311  and a plurality of contacts  312 . Each nose chip holder  315  may include a plurality of electrical leads  340  electrically connected to corresponding ones of contacts  312  and disposed on the holder such that when that holder is in its sensing position beneath a corresponding receiver  115  ( FIG. 1 ) containing one of stoppers  110  to be tested, the leads and probe fingers  330  may be contacted together so as to activate the corresponding nose chip  310  for testing that stopper. Such contact may be effected by moving nose chip holder  315  and/or probe fingers  330  into contact with one another.  
         [0039]     Each nose chip  310  may include a sensor array containing a plurality of sensor elements  311  that detects a chemical analyte, such as TCA. Electrical traces or leads (not shown) may extend from sensor element  311  to contact pads  312  to electrically connect them to one another. Suitable sensor arrays include, but are not limited to, bulk conducting polymer films, semiconducting polymer sensors, surface acoustic wave devices, and conducting/nonconducting regions sensors. In one example, each nose chip  310  is a conducting/nonconducting region sensor in which conducting materials and nonconducting materials are arranged in a matrix (i.e., a resistor) and provide an electrical path between electrical leads. The nonconductive material may be a nonconducting polymer, such as polystyrene. The conductive material may be a conducting polymer, such as carbon black, an inorganic conductor. In use, the resistor provides a difference in resistance between the electrical leads when contacted with an analyte. In one example, nose chip  310  includes a sensor array specific for detection of a single analyte, such as TCA. Alternatively, nose chip  310  may include a sensor array for detecting two or more compositionally different analytes.  
         [0040]     Each nose chip  310  may be attached to a corresponding nose chip holder  315  via wire bonds (not shown) between contact pads  312  and leads  340  on nose chip holders  315 . Leads  340  may be formed of any suitable material, such as a metal foil for conducting electrical current between nose chips  310  and probe fingers  330 . Probe fingers  330  provide a mechanical means to electrically connect nose chip holders  315  to sensor electronics  225 . Probe fingers  330  may provide standard electrical connections for lines, such as electrical power, ground, data input, and data output. Alternatively to providing probe fingers  330 , each nose chip  310  or nose chip holder  315  may have an on-board power supply (not shown), e.g., battery, for providing power to that nose chip and a wireless communication device (not shown), e.g., an infrared or radio frequency transceiver, for providing the communication link between the nose chip and sensor electronics  225 .  
         [0041]     Nose chip holders  315  may be attached to and carried by web  320 , which may be formed of any suitable material, such as polyurethane or rubber, which provides a suitable support for the nose chip holders. Web  320  may be a continuous belt that is positioned around rollers  325 . Web  320  may be advanced, for example, in a clockwise rotation, by rollers  325  to align nose chips  310  with sensor electronics  225 . If finger probes  330  or other contact-type links are provided, they may be moved into contact with leads  340  using a suitable actuator (not shown) that may move the probes and/or sensor electronics  225 . Alternatively, when one of nose chip holders  315  is in its sensing position, that holder may be moved into contact with finger probes  330 , e.g., using an elevator (not shown) or other means. Rollers  325  may be conventional rollers formed of any suitable material, such as rubber or metal.  
         [0042]     Nose chip holders  315  may be provided in any number on web  320  to suit a particular design. For example, if nose chips  310  are recycled, i.e., used over to test at least a second stopper  110  ( FIG. 1 ), the number of chip holders  315  and nose chips  310  will generally depend upon the recycle time, i.e., the time it takes a nose chip to recover from a worst-case analyte detection so as to be ready to detect the presence of the analyte again, and the frequency of the testing. For example, if the maximum recycle time for nose chips  310  is 60 seconds and the frequency of the testing is 0.5 seconds, then the number of nose chip holders  315  and nose chips should be greater than 60/0.5=120 to allow sufficient time for the worst-case nose chip(s) to recycle for another test. Alternatively, if nose chips  310  are not recycled but rather used only once, the number of nose chip holders  315 , if such holders are needed at all, may be practicably as few as two for a web-type delivery system, e.g., one of the two holders may be loaded with a fresh nose chip  310  while the other one is being used for a test. Then, the used nose chip may be removed from its holder as the fresh nose chip is moved into position for testing. Of course, more than two nose chip holders  315  may be used if desired. A single nose chip holder  315  may also be used, but would not be as efficient as having two or more such holders. Those skilled in the art will readily appreciate that nose chips  310  and/or nose chip holders  315  may be delivered to their testing locations by means other than a web-type conveyor. Such alternatives include other types of linear conveyors, rotational moving devices, ribbon-type feeding devices and cartridge-type feeding devices, among others.  
         [0043]     Nose chip holders  315  and/or nose chips  310  may be covered with a removable cap (not shown) to protect nose chips  310  prior to a testing event. The arrangement of nose chip holders  315  and nose chips  310  on web  320  contains sufficient spacing between adjacent nose chip holders  315  such that nose chips  310  are not contaminated by overflow air during a testing event. For example, nose chip holders  315   b,    315   c  and  315   d  are sufficiently spaced from nose chip  310  such that when air is passed over nose chip  310 , the nose chips on nose chip holders  315   b,    315   c,  and  315   d  are not contaminated by overflow air when nose chip  310  is used to test stopper  110  ( FIG. 1 ).  
         [0044]     Referring to  FIG. 3B , sensor electronics  225  may include a power regulator  345 , a microprocessor  350 , a memory  355 , an analog-to-digital (AID) converter  360 , a digital-to-analog (D/A) converter  365 , a timing and control circuitry  380  and a computer interface  385 . Power regulator  345  may provide electrical power to microprocessor  350 , nose chip holders  315  and nose chips  310 . As mentioned above, electrical power to nose chip holders  315  and nose chips  310  may be provided via probe fingers  330 . For example, electrical power may be provided by probe finger  330   a  and ground provided by probe finger  330   b.  Power regulator  345  may provide a regulated or limited amount of power to nose chip holders  315  and nose chips  310  to optimize performance of nose chips  310 .  
         [0045]     Microprocessor  350  may include the necessary processing electronics to extract and execute instructions stored in memory  355 . Such processing electronics are well-known in the art and, therefore, need not be described in detail herein for those skilled in the art to understand and practice the present invention. Memory  355  may provide storage of program codes, data, and other information. Examples of program code stored in memory  355  include program code that coordinates the operation of sensor units  135  and sensor pattern signal handling and pattern recognition algorithms or look-up tables to analyze data from nose chips  310 .  
         [0046]     A/D converter  360  may provide analog-to-digital conversion of data (e.g., resistance measurements) as it passes from nose chips  310  to microprocessor  350  for further processing. D/A converter  365  may provide digital-to-analog conversion of data as it passes from microprocessor  350  to nose chips  310 . Timing and control circuitry  380  may provide, for example, timing signals for data acquisition from nose chips  310  and indexer functions to coordinate the advancement of web  320  by rollers  325 . Interface  385  facilitates communication between sensor electronics  225  and computer  205  and is in communication with computer  205  via communication link  210 .  
         [0047]     The identification of an analyte may occur as follows. Power regulator  345  provides an electrical signal to nose chips  310 . A series of electrical traces (not shown) from each one of sensor elements  311  of nose chips  310  are connected to provide an electrical path through leads  340  and probe fingers  330  to A/D  360  and microprocessor  350 . Microprocessor  350 , using instructions stored in memory  355  and in timing and control circuitry  380 , converts an electrical signal generated from sensor elements  311  of nose chips  310  into a processed output signal. The instructions stored in memory  355  may include, e.g., a look-up table that compares incoming signals to stored reference values to provide an analysis. Alternately, an algorithm or other analytical means for providing a chemical analysis can be provided. In the presence of an analyte, e.g., TCA, a change in electrical resistance is detected and processed by microprocessor  350 . The results are output via interface  385  and communication link  210  to computer  205 .  
         [0048]      FIG. 4  illustrates a method  400  of using apparatus  100  of  FIG. 1  to provide screening of 100% of cork stoppers produced by a cork stopper manufacturer. Of course, method  400  and apparatus  100  may be adapted for testing of virtually any item other than a cork stopper, e.g., packaging, such as containers, lids, caps, etc., for foods and beverages.  FIGS. 1-3  are referenced throughout the steps of method  400 , which may include the following steps. Those skilled in the art will recognize that method  400  is merely exemplary. Accordingly, the various steps of method  400  may be modified, deleted or replaced as needed to suit a particular design.  
         [0000]     Step  405 : Setting Parameters  
         [0049]     In this step, a user sets parameters for the testing operations desired. Examples of testing parameters include the number of stoppers  110  to be tested, the analyte(s) to be detected (e.g., TCA), acceptable concentration levels, i.e., testing thresholds, for the analyte(s), and baseline resistance values for sensor elements  311  for re-use calibration. Testing thresholds may be adjustable/selectable, e.g., to allow for quality variations or suit the particular items being tested. Testing threshold ranges will typically be dependent upon the sensitivity of nose chips  310  or other sensor to the analyte(s) being tested. For example and with regard to TCA, the most adept humans have a detection threshold of about 10-20 parts-per-trillion (PPT) in air. Consequently, it is desirable that nose chips  310  be able to detect the presence of TCA at a level lower than 10-20 PPT at the same conditions. Method  400  proceeds to step  410 .  
         [0000]     Step  410 : Checking all Nose Chips  
         [0050]     In this step, sensor unit  135  performs a scan of nose chips  310  on web  320  to ensure that all nose chips  310  are operational. For example, sensor electronics  225  may determine the baseline resistance values of sensor elements  311 . If the baseline resistance values are at or above a certain value, nose chips  310  are reset or discarded and replaced. Method  400  proceeds to step  415 .  
         [0000]     Step  415 : Dispensing Stoppers  
         [0051]     In this step, individual stoppers  110  are dispensed into receivers  115  in web  120 . For example, software algorithms on conveyor controller  220  (e.g., web controller  240 ) are used to move rollers  150  and align web  120  with hopper/dispenser  105  such that receiver  115   a  is directly beneath the hopper/dispenser. Stoppers  110  in hopper/dispenser  105  are dispensed into receiver  115   a  using software algorithms in hopper/dispenser controller  230  such that a single stopper  110  is dispensed. Web  120  is advanced, for example, in a clockwise direction, and the process is repeated until the appropriate numbers of receivers  115  (e.g., receivers  115   b,    115   c  and  115   d ) are filled. Method  400  proceeds to step  420 .  
         [0000]     Step  420 : Activating Airflow  
         [0052]     In this step, airflow is activated and directed or drawn over stoppers  110  in receiver  115  to extract chemical vapors (e.g., TCA) from stoppers  110 . For example, air movers  130  may be activated using software algorithms in air mover controller  250  to provide airflow (e.g., a flow of heated air) over stoppers  110 . As air flows past stoppers  110 , the chemical vapors from stoppers  110  are mixed with the heated air and are carried toward sensor units  135 , where sensor elements  311  on nose chips  310  are exposed to the air/vapor mixture. Method  400  proceeds to step  425 .  
         [0000]     Step  425 : Sensing Analyte  
         [0053]     In this step, each sensor unit  135  determines the level of one or more analytes in the air/vapor mixture. The identification of an analyte typically occurs as follows. An electrical signal is provided by power regulator  345  to nose chips  310 . A series of electrical traces (not shown) from each of sensor elements  311  of nose chips  310  are connected to provide an electrical path through leads  340  and probe fingers  330  to A/D  360  and microprocessor  350 . Microprocessor  350 , using instructions stored in memory  355  and in timing and control circuitry  380 , converts an electrical signal generated from sensor elements  311  of nose chips  310  into a processed output signal. The instructions stored in memory  355  include, for example, a look-up table that compares incoming signals to stored reference values to provide an analysis. Alternatively, an algorithm or other analytical means for providing a chemical analysis can be provided. In the presence of an analyte, e.g., TCA, a change in electrical resistance is detected and processed by microprocessor  350 . The results are output via interface  385  and communication link  210  to computer  205 . Method  400  proceeds to step  430 .  
         [0000]     Step  430 : Advancing Web  
         [0054]     In this step, web  120  is advanced an appropriate increment to position the receiver, e.g., receiver  115   d,  in proximity to diverter  145 . Method  400  proceeds to step  435 .  
         [0000]     Step  435 : Bad Stopper? 
         [0055]     In this decision step, software algorithms in sensor electronics  225  determine whether any of the one or more undesirable analytes being tested, e.g., TCA, is present on stopper  110 , as measured by the corresponding nose chip(s). If yes, method  400  proceeds to step  440 . If no, method  400  proceeds to step  450 .  
         [0000]     Step  440 : Diverting Stopper  
         [0056]     In this step, diverter  145  is activated using software algorithms in diverter controller  260  and a rejected stopper  110  is diverted to reject bin  165 . Nose chip  310  corresponding to that rejected stopper  110  may be discarded with the rejected stopper or, alternatively, may be recycled and reset for re-use, depending upon the reusability of the nose chip. Bin full controller  270  may monitor the levels of rejected stoppers  110  in reject bin  165 , and a signal is generated when reject bin  165  is full. Method  400  proceeds to step  445 .  
         [0000]     Step  445 : Replacing Nose Chip  
         [0057]     In this step, if nose chips  310  are of the non-reusable type, a new nose chip  310  and/or nose chip holder  315  is replaced on web  320 . Method  400  may proceed to step  455 .  
         [0000]     Step  450 : Collecting Stopper  
         [0058]     In this step, web  120  is advanced an appropriate increment to position the receiver, e.g., receiver  115   d,  in recess  155  of roller  150   a.  As receiver  115   d  is advanced over roller  150   a,  stopper  110  in recess  155  falls out of receiver  115   d  into accept bin  160 . Bin-full controller  270  may monitor the levels of collected stoppers  110  in accept bin  160  and generate a bin-full signal when the accept bin is full. Method  400  proceeds to step  455 .  
         [0000]     Step  455 : More Stoppers? 
         [0059]     In this decision step, it is determined whether additional stoppers  110  are available for screening. For example, the total number of stoppers  110  to be screened are set in step  405  and software algorithms are used to track the number of stoppers  110  dispensed from hopper  105  and screened by sensor units  135  to determine whether a stopper  110  remains to be screened. If yes, method  400  returns to step  410 . If no, method  400  ends.  
         [0060]     While the present invention has been described in connection with a preferred embodiment, it will be understood that it is not so limited. On the contrary, it is intended to cover all alternatives, modifications and equivalents as may be included within the spirit and scope of the invention as defined above and in the claims appended hereto.