In the swim of flow

swim of flow injection analysis. "Versatile" is the word that best describes flow injectton analysis sFIA). First devel- oped 20 years ago, the analyt...
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In the swim of flow injection analysis "Versatile" is the word that best describes flow injectton analysis sFIA). First developed 20 years ago, the analytical method has found a home in environmental, pulp and paper, agricultural, pharmaceutical, and clinical testing laboratories as well as in the industrial plant as an on-line process control analyzer. "It performs wet chemistry efficiently and quickly," says FIA expert Gary Christian from the University of Washington. A basic FIA laboratory setup consists of a precisely controlled pumping system, an injection system designed for reproducibility, aflowcell, and a detection system. "The detector can be almost anything from a spectrophotometer to a mass spectrometer," says Christian. A typical FIA laboratory analysis takes less than 2 minutes and is very reproducible. "Anything that can be done with wet chemistry can be done with this technique," states Frank Hoek, marketing manager with Ionics Inc.'s instrument division.

Manufacturers cater to specific applications Basically, the FIA technique introduces a sample into a flowing liquid carrier stream where it physically disperses. A reagent or reagents can be added to the carrier stream for analyte detection or titration. Samples are analyzed in a flow cell, where the analyte emerges as a typical "peak." FIA also handles liquid-liquid extraction by introducing a second solvent into the FIA stream prior to detection. Solvent and reagent consumption during a standard FIA run are low typically in the microliter range and sample throughput is high Potentially dangerous chemicals contained in the closed cvstem "It

is a precisely timed experiment," notes Scott Stieg, vice president of R&D at Lachat Instruments. FIA states Christian, is also a method about which much has been published. Readers lookingior detailed information should check recent reviews and monographs in addition to books and journal articles {1-5). Commercially available FIA instruments range from simple manual devices to automated systems for near-continuous monitoring. The market consistently attracts new companies. Indeed, Christian and FIA inventor Jaromir Ruzicka have formed a company, Alitea USA Features for eight representative commercial FIA systems are listed in Table 1. Some manufacturers have provided additional details on their products, which can be retrieved by sending an e-mail message with the appropriate keyword (found at the bottom of each column in the table on p. 204 A) in

Analytical Chemistry News & Features, March ar 1996 203 A

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the subject line to our reflector service at [email protected]. Readers should be careful about making comparisons based solely on information in the table. The Eppendorf and Ionics model 3800 FIA process analyzers do not compete against the other FIA instruments, which are designed for the lab bench. To varying degrees, many FIA systems are dedicated to specific tasks, which may be the overriding criteria for many customers. Other FIA instruments are modular and can be connected in

several arrangements or to various other instruments. And, the listed automated FIA instrument from Global FIA is a simple example of a customized analyzer. The company supplies a wide range of FIA components for do-it-yourselfers as well as software and customized benchtop and on-line analyzers. A sense of mission

FIA customers fit into two broad classes, says Christian. "Some people buy an instrument to solve a particular problem;

others want a general-purpose or research instrument." According to Christian, for problem solvers the companies market instruments with chemistries and designs optimized for particular applications. Says Stieg, "We sell the methods and use FIAs to compete on that basis." For example, Lachat and other FIA manufacturers supply packages for measuring analytes such as mercury, ammonia, glucose, and chloride ions and properties such as pH and water hardness.

Table 1. Summary of representative products Product

FIAIab-3000

Company

Alitea P.O. Box 26 Medina, WA 98039 206-453-4135

Price Dimensions (w X d X h;cm) Weight (kg) Application

-$11,000 20X25X29

Pump

Pump rate Sample injection

Sample volume Manifold Sample throughput Detector

Eppendorf Variable Analyzers Amko Systems 250 West Beaver Creek Unit 6 Richmond Hill, Ontario Canada L4B 1C7 905-771-1444

Eppendorf Process Analyzers Amko Systems 250 West Beaver Creek Unit 6 Richmond Hill, Ontario Canada L4B 1C7 905-771-1444

Custom FIA/SIA Analyzers Global FIA P.O. Box 2297 Gig Harbor, WA 98335 206-265-8586

from $3000 14.1X24.1X21.9 (individual module) 3.5 (individual module) General and specified by module choice

from $48,000 7 6 X 4 6 X 190

$7000-$10,000 45X40X45

90 Process analysis

15-20 Bench-top and on-line analysis

24,000-step piston motor, auxiliary 2-channel peristaltic pump 0.05-5 mL/min 8-position selector valve

Peristaltic with options to run as 2, 4, or 6 channels

Syringe and peristaltic

1-1, 450 mL/h Programmable 8-port rotary inject valve

Sample is process stream driven, reagents are pneumatically pumped Not applicable Slider or rotary valve (handies 2 different volumes)

5-200 uL

> 2 uL

> 2 uL

60-90/h

20/h

Continuous monitoring

Option of optical detection system for sandwich flow

Option of filter photometer, 1 or 2 ion-selective electrodes, gas-sensitive, headspace gas, or conductivity detectors Autosampler, 8-port programmable selector valve

Option of UV, IR, ion-selective electrode, headspace gas, colorimetric, or conductivity detectors

Modules are microprocessor controlled through master controller module, which will also automate calibrations

Microprocessor controlled, auto-calibration, programmable alarms

Modular design, customized by user, master module can automate other lab procedures

Long periods of unattended operation, analysis performed at process pressure

402 acFIA663

403 acFIA664

6j>

General laboratory, solution handling, portable

cell

Accessories

Automated operating system and software

Special features

Universal sandwich membrane flow cell for visible spectrophotometry Windows-based FIA lab software, automated system control, stopped-flow analysis, external device and autosampler control Also operates as sequential injection analysis

Reader service number 401 E-mail reflector keyword acFIA662

204 A

Analytical Chemistry News & Features, March 1, 1996

High pressure-bypass filtration systems

0.5-5 mL/min Range of Valco "intelligent" injection and selection valves > 1 uL (Variable volume sample loop) Customized for application Dual wavelength LED photometers, CCD array spectrophotometer, amperometric and potentiometric electrochemical detectors Broad range, including tubing, valves, gas diffusion and permeation units, detectors Flow-TEK automated FIA and SIA software for lab, process, or on-line environment "One-stop shopping," modular design, flexible user-designed configuration, same software for laboratory to process stream 404 acFIA665

Perkin Elmer also emphasizes FIA as an application, viewing the system as an accessory to other analytical instruments, says technical marketing manager Chuck Schneider. As such, the company promotes FIA with other products like the atomic absorption, MS, and inductively coupled plasma MS instruments. This combinationfillsapplications like measuring mercury in blood and urine or analysis of seawater, says Schneider. Lachat, too, mixes instruments with applications. Its QuikChem system

hooks up to a high-pressure injection pump for running samples by chemically suppressed ion chromatography. It also feeds samples into a cold-vapor Hg atomic absorption instrument. Perstorp's FIAstar 5012 unit comes standard as a dual channel system—a popular choice among analysts who want to save time handling two analyses at once, says product specialist Shirley Arment. For example, one can run nitrogen and phosphorous from the same Kjeldahl digestion.

Alitea's FIAlab-3000 is designed to connect with a variety of detectors, including fluorescence microscopes and FT-IR spectrometers. Both Alitea and Global FIA also offer sequential injection analysis (SIA), a newer method that allows analysts to change reaction conditions (e.g., chemistries, and sample and reagent volumes) by computer keyboard rather than by physically reconfiguring manifolds or valves, says Christian. Samples and reagents are aspirated, which eliminates the injection valve in an SIA instru-

3800 FIA

QuikChem 8000

FIAstar 5012

FIAS-100 a n d - 4 0 0

Ionics, Inc. Instrument Division 65 Grove St. Watertown, MA 02172 617-926-2500

Lachat Instruments 6645 West Mill Rd. Milwaukee, Wl 53218 414-358-4200

Perstorp Analytical Inc. 1210 Tech Rd. Silver Spring, MD 20904 301-680-0001

Perkin-Elmer Corp. Analytical Instruments 761 Main Ave. Norwalk, CT 06859 800-762-4000

from $20,000 68X35X64

$16,000-$60,000 152X91X61

$i5,000-$25,000 325X355X220

$12,000-$15,000 41.5X41X18.2

70

10-30

11

11.2

Process analysis

Ion analysis, environmental, agronomy, industrial

Water, environmental, agricultural analysis

Sample preparation, mercury, hydrides, speciation, preconcentra-

Rotary piston design

Peristaltic pump

2 peristaltic pumps with 8 channels each

0.5-25 mL/min Multiposition valve, 6-port rotary valve

0.5-4 mL/min 6-port rotary valve

0.5-3 mL/min Rotary valve

1 (100) or 2 (400) peristaltic pumps with digital stepping motors with up to 8 channels 0-120 rpm 5 port switching valve

10uL-5mL

5 uL-5 ml_

40-200 uL

20 uL-1 mL

Continuous monitoring

90/h

60-90/h per channel

120/h

Application-dependent selective ion, pH, or oxidation-reduction potential electrodes; specific wavelength coulometer

Options of conductivity, atomic absorption, atomic fluorescence, or photometric detectors

2 filter photometers standard, option of fluorometer, flame fluorometer, ion-selective electrode

Option for AA, UV, ICP, ICPMS

Configured for application (e.g. ammonia, hardness, caustic, HCI, or HCIO analyzer) Microprocessor controlled, multipoint calibration, alarm for over range, output to printer

Autosampler, automatic dilution station

Autosampler, dialysis and extraction modules, thermostat, solventresistant manifold SuperFlow EX software for automated system control, stoppedflow analysis, data handling and reporting, methods protocols

Autosampler, dedicated mercury analyzer, amalgamation, on-line microwave digestion Controlled through instrument software (e.g. AA/ICP WinLab, ELAN NT software)

EPA-approved total Kjeldahl nitrogen by gas diffusion method

Only commercial FIA available for use with atomic spectroscopy techniques

407 acFIA668

408 acFIA669

(dual enclosures)

(FIA alone)

tion

Simple design, no maintenance/service pumps, commercially available detectors 405 acFIA666

Windows-based Data Quality Management software for QA/QC and Contract Lab Program, sets conditional levels, checks standards Easily combined with chemically suppressed ion chromatography

406 acFIA667

Analytical

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ment. As a result, says Christian, these systems are mechanically simpler and use less reagents. All other operations are the same. Alitea offers a dedicated SIA instrument (FIAlab 3300) and an instrument for FIA and SIA (FIAlab 3500). In addition, the company markets a low-priced manually operated FIAlab 2000 for student laboratories and methods development. Amko's Eppendorf Variable Analyzers are designed as modular systems. "It is customized by the end-user," says Erik Zamurs, technical manager with Amko Systems. The system features a "master module," which not only automates the operation of the other modules but can coordinate other devices in the laboratory says Zamurs. Frustration over having to buy components from different companies was one reason Don Olson founded Global FIA. The company specializes in provid-

One feature all the experts agree on is FIA's simplicity. ing a broad range of supplies along with customized systems. Among its products is a portable or "roll-up" analyzer system for monitoring wastewater or process streams. Most laboratory instruments use a peristaltic pump to propel the carrier stream. As such there are few variables to control. Pump speed and tubing diameter determine flow rate, and the injection valve controls the sample amounts. Because the peristaltic pump will wear the tubing and lead to changes in calibration some systems offer a piston or syringe pump instead. With some training most analysts should be able to run FIA successfully say the experts. Indeed one feature all the experts agree on is FIA's simplicity In addition to the laboratory market, FIA systems have served in automated on-stream analysis in process control situations. These instruments are generally rugged, mounted on tall instrument racks, and weigh more than 100 lbs.

Analytical Chemistry News & Features, March 1, 1996

According to Hoek, Ionics' 3800 FIA process analyzer needs to be visited only weekly—primarily to refill reagents and for quick visual inspections. Zamurs says that the Eppendorf unit can go as long as four weeks between visits. Both these process systems are microprocessor controlled. In these systems, samples are removed from the process stream for analysis. For example, the Eppendorf FIA analyzer has a bypass system that can sample up to eight streams, returning the unused portions. Hoek says that Ionics will customize a system to a user's needs, and then try to launch the application into a broader market. "We don't build an analyzer that the customer has to be creative to use." In addition to traditional chemical manufacturing plants, markets for these rugged process analyzers include the pharmaceutical industry, fermentation plants, and wastewater monitoring systems says Hoek. Global FIA's roll-up analyzer also fits this market handling short-term assignments such as monitoring a pilot plant stream or troubleshooting a process line The FIA market is very competitive, says Arment The competition, however, is broader than just FIA. Professionals from a number of companies admit they must compete against continuous flow and the more expensive, segmented flow methods. "For the past six or seven years I have been on a missionary sell [for FIA]," says Stieg. "It is just entering a maturing phase." Adds Schneider, FIA beats the other approaches by requiring far smaller volumes of liquids and reagents running at faster speeds and offering an easier-to-use system It all back to versatility Alan Newman References

(1) Christian, G. D. Anall Chem. 1995, 67, 532 A. (2) Andrew, K. N. et. si. Anal. Chem. 1994, 66,916 A (3) Valcarcel, M.; Luque de Castro, M. D. Flow Injection Analysis: Principles and Applications; Ellis Horwood: Chichester, U. K., 1987. (4) Fang, Z. Flow Injection Separations ons Preconcentrations; VCH: Weinhelm, 1993. (5) Ruzicka, J.; Hansen, E. H. Flow Injection Analysis, ,2d ed.; Wiley-Interscience: New York, 1988.