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A simplified fluorometric fluoride analyzer
Atmoqheric
Environment, PerBamon Press 1967. Vol. 1, pp. 253-259. Printed in Great Britain.
A SIMPLIFIED
FLUOROMETRIC
FLUORIDE
ANALYZER
C. RAY THOMPSON,L. F. ZIELENSKI and J. 0. IVIE+ Statewide Air Pollution Research Center University of California, Riverside, California, U.S.A. (First received 30 October 1966 and in final form 23 January 1967) Ahstraet-A fluorometric fluoride analyzer previously described (Ivu? et al., 1965) has been redesigned and simplitied to provide a more usable instrument. A single photomultiplier tube is used to receive alternate light pulses rather than the two tubes used formerly. Illumination of the sensitized tape is accomplished by two ultraviolet lamps. The electronic circuitry for tape i~u~ation and carryiug of signals to the recorder has been simplified. A light “piping system improves light transmission and the bulk and weight of the overall equip~nt has been reduced to about one-half. INTRODUCTION
THE MEASUREMENT of hydrogen fluoride in the atmosphere in the fraction of microgram per cubic meter levels continues to be a problem. The Mini-Adak II recorder developed by ADAMSand KOPPB(1962) is advertised to measure as little as 0.3 pgfm3 when this level persists for 35 min. Con~ntra~ons lower than this can damage sensitive plants if present continuously; thus a means for recording these lower levels is needed. The fluorometric fluoride analyzer originally designed by Chaikin, Thomas and coworkers (CHAIKIN, 1952; CHAIKINet al., 1953; CHAIKINet al., 1954; CHAIKIN et al., 1956; THOMASet al., 1958) and later modified by IVIEet al. (1965), has the sensitivity required to measure these lower levels but has several shortcomings which have precluded its manufacture and general use. This analyzer samples the atmosphere through parallel warmed glass tubes, one of which absorbs HF in a thin coating of NaHCO,. The two airstreams are then drawn through adjacent portions of a paper tape impregnated with the magnesium salt of 8-hydroxyquinoline (CLAUS&1957), (FEIGL and HESSIG,1949) and (CHLECKet al., 1955). Gaseous HF quenches the fluorescence of the salt which is excited by an ultraviolet lamp. The difference in emitted light output is indicated on a strip chart recorder. EXPERIMENTAL The present anaIyzer uses the same kind of air sampling tubes as used previously and has heaters to maintain incoming air at temperatures 5-VC above ambient (FIG. 1). Heat is required to raise the air temperature above ambient and thus lower relative humidity because at near saturation the bicarbonate coating of the reference tube takes up water, dissolves, and as droplets has so little surface area that HF passes through the tube. Also, if water condenses on the clean tube HF will be absorbed and the differential between the two tubes will again be upset. At higher temperatures the air passing through the paper tape heats the Ghydroxyquinoline and inhibits its fluorescence. Raising the temperature of the air at the block to 64°C caused no loss of
* This investigation was supported in part by Public Health Service Research Grant AP 00244-02 from the Division of Aii Pollution, Bureau of State Services, Public Health Service. t Present address: Instrument Development Co., 11455 Newton Square South, Reston, Virginia 22061. 253
254
C. RAY THOMPSON, L. F. ZIELENSIU and J. 0. IVIE
response when the analyzer was sensing 0.14 pg/m3 of HF but at 71°C the response was completely inhibited. The electronic circuitry has been changed so that a single photomultiplier tube serves to receive the light from the sensitized tape rather than the two tubes used formerly. This eliminates two serious sources of trouble which arose when two photoSAMPLEINLET
t
SAMPLEINLET
Recorder
t
FIG.1, Pictorialdiagramof componentparts of fluorideanalyzer. multiplier tubes were required, the problems being caused by a great difference in the sensitivity of the two tubes with aging, and the length of time required to select and test a given pair of tubes. A large stock of tubes was required at all times, and several days of trial operation were often required to balance the output from two photomultiplier tubes in order to establish a zero base line. It was often necessary to change one or both tubes and then repeat the trial operation before two tubes with sufficiently equal sensitivity could finally be found. In the original instrument (THOMASet al., 1958) the light source for exciting the
A Simplified Fluorometric Fluoride Analyzer
255
fluorescence of the sensitized tape was a single U.V. emitting lamp. The lamp was lighted by a radio frequency voltage necessitating the use of a radio frequency oscillator. This has been eliminated and presently two U.V.emitting lamps are lighted by a less complex method incorporating a high voltage transformer to supply a stabilized voltage working directly off the commercially available a.c. power line. The high voltage output from the transformer is alternately fed to each of the two lamps through solid state rectifiers. A Leeds and Northrup synchronous converter is used to transfer the output from the photomultiplier tube to the reference and sampling measuring circuits in synchronism with lamp illumination (FIG. 2).
FIG. 2. Schematic diagram of fluorometric fluoride analyzer. Component parts identification of FIG. 2 Circuit reference
Description
Cl c2 c3, C4 C5, C6 C7, C8 C9, Cl0 Cll, Cl2 Cl3 c14, Cl5
Capacitor, Capacitor, Capacitor, Capacitor, Capacitor, Capacitor, Capacitor, Capacitor, Capacitor,
CRl, CR2 CR3, CR4, CR5, CR6
Diode, 1NlllO Diode, lN34A
E
6mfd, 600 V d.c. O.Smfd, 600 V d.c. O.OOlmfd,400 V d.c. O.OSmfd,400 V d.c. Smfd, 25 V d.c. 25mfd, 25 V d.c. 4Omfd, 140 V d.c.-Sprague TVA 2445 2.3mfd, 330 V a.c.-Leeds and Northrup No. 023126 2Omfd, 400 V d.c.
256
C.
RAY
THOMPSON,
Component
L. F. ZELENSKIand J. 0. Ivrs
parts identification
of Pro. 2 (continued)
Circuit reference
Description
Fl
Fuse, 2 amp
Kl K2 K3 K4 K5 K6 K7
Time Delay Relay-Amperite 115C15T Time Delay Relay-Amperite 115N015T Time Delay Relay-Amperite 115C3OT Time Delay Relay-Arnperite 115NO2OT Potter and Brumtield Relay KRPI 1A Photomultiplier Signal Transfer Relay-Leeds 354156 Clamping Block Solenoid-Assco No. 2X867
Ll
Filter Choke, 16h, 15 mA
Ml M2 M3
1 rev/min Tape Advance Motor-Dayton Mfg. Co. Type 4K807 Tape Advance Timing Motor-2 rev/hr Synchron Motor 1138RC12-60 Balance Motor-Leeds and Northrup No. 017138
PM1
Photomultiplier
Rl-R9 R10 Rll R12 R13, R14, R15 R16 R17 R18, R19 R20, R21, R22 R23, R24 R25, R26 R27 R28 R29 R30 R31 R32 R33 R34
Resistor, Resistor, Resistor, Resistor, Resistor, Resistor, Resistor, Resister, Resistor, Resistor, Resistor, Resistor, Resistor, Resistor, Resistor, Resistor, Resistor, Resistor, Resistor,
Sl s2 s3 S4 s5
Manual Tape Advance Switch Automatic Tape Advance Switch Recorder E+xnal “On-off” Switch Main Power Switch Scale Switch-Centralab No. 1401
Tl T2 T3 T4
High Voltage Transformer-Ultraviolet Variable Autotransformer-Superior Transformer-Triad R-7A Constant Voltage Transformer-Sola
Tube-Dumont
27OkQ 1/2W 33OkQ 1/2W 47OkQ 1/2W 15kn, 5W 4.7MR, 1/2W 5MQ 1/2W Ma, 1/2W lOkQ, 1W lOOkR, 1/2W 1OkQ 1/2W m, 1/2W 5wZ, 10 Turn-Spectral 84kQ rt lx, 1/2W 8kQ rf:lx, 1/2W 4kn, + 1%. 1/2W 2Kz, + lx, 1/2W lkn, + lx, 1/2W lKz, + lx, 1/2W 1OkQ 2W
and Northrup
No.
6467
Model 810
Products, Inc. Model XT-1 RIectrIc Co. Type 10 CVH-1
(Facing p_ 256)
A Simplikd Fluorometric Fluoride Analyzer Component parts i~tifi~~n
257
of Fro. 2 (~~
circuit rt!ference
Description
UVl, UV2
Ultraviolet Sources--Ultraviolet Products, Inc. Model llSG1
Vl v2 v3 v4
Electron Tube, 12AU7 Electron Tube, 6X4 Electron Tube,0A2 E%ctronTulE, OB2
.~
Because illumination of the sensitized paper tape gave diffused light for detection by the photomultiplier tubes, a new optical system was designed. A mirror arrangement in the older instrument which wasted much of the radiant energy was replaced by a truncated plastic cone which “piped” the light directly to the single photomultiplier tube. A narrow pass interference filter (Bausch and Lomb #44-7836) was used to isolate the 3650 A lightfrom the u.v. lamp which excited the fluorescence of the paper tape. This eliminated other visible radiation which appeared as “background” light on the sensing tube, An end window photom~tip~er tube which has a greater light collection efficiencyand minimized reflectance losses was substituted for the previously used side-window tubes. To check the efficiency of the new optical system a type 51 incandescent lamp, designed to be lighted by a 6 V source, was substituted for the U.V.source and the following tests were made with the analysers in their normal operating ~~~mtion but with the paper tape removed. The lamp was connected to a 1.5 V battery so that it was barely lighted. The voltage output from the photom~tip~er tube in the new system was 62 V. For the system using mirrors the output of the photomultiplier tubes was 0.36 and 0.26 V, respectively. A second test was performed with an International Rectifier Corp. type A5PL selenium photocell which was substituted for the photomultiplier tubes. In this trial, using the 1.5 V battery to ~u~nate the lamp, current output of the photocelI in the new optical system was 16 x IO-’ amp while output from the mirror system was 41 x lo-l2 amp. A repeat of this test but with a 6 V battery gave 6 x 10m6amp for the new optical system and 12 x lo-’ amp for the old. With the increased sensitivity it was possible to reduce instability caused by noise. Both bulk and weight have been reduced to about one-half that of the previous equipment (FIG.3). After the design of the analyzer was completed several weeks were devoted to checking tim=oncentration response of the instrument to standard hydrogen fluoride atmospheres. These atmospheres were prepared by rno~~g a very fine dust filter (HP-200, Dust Control, Inc.)* capable of removing particulate matter down to the 0.3~ range upstream from an HF dispenser. The rated capacity of this filter was about fifty times that at which it was operated, thus giving high filtration efficiency. Gaseous hydrogen fluoride was dispensed into the intake of a small squirrel cage blower which diluted the gas to the desired concentration (THOMPSON and Ivm, 1965).The gas came from a concentrated solution held at 0’ C. Gas concentration was varied by changing * Dust Control Inc., 1144 W. 135th Street, Chrden8, california
258
C.
RAY
THOMPSON, L. F.
ZIELENSKI
and J. 0. IVIE
the airflow being bubbled through the solution. Two air samples, one to an impinger, the other to the analyzer were drawn from the blower exhaust at the same point. Calorimetric measurement (BELLACK and SCHOUBOE, 1958) of fluoride in the impinger sample was used to calibrate the inst~ment (FIG. 4). The curve shows the linear regression of the recorder reading on fluoride content of the air samples as calculated by the method of least squares. Daily operation for several weeks showed it to be reliable in performance.
1
0.1
0.2
O‘S
0.4
0.5
Micto@uns FItwide per Cubic Meter
FIG. 4. Comparison of recorder response to increasing;~n~ntrations of HF as determined
cn~orimet~~lly.
~~n~w~e~e~~ts_The technical assistanceof KENNETHM. HOLTZCLAW and isgratefully a&now&edged.
EVELYN
E. LUNDIN
REFERENCES ADAMSD. F. and KOP~ER. K. (1962) A field evaluationof the mini-Ads II autonlatic fluoride air pollutant analyzer. J. Air PO&t. Control Ass. X2,164-169. BELLACK I.and SCHO~,~OE P. J. (1958) Rapid photometric determination of fluoride in water. Analyt. m
Chem. 30,2032-2034. S. W. (1952) C~nti~~o~~~oride analyzer. Stanford Research Institute Technical Report No.
I, pp. 21-31, August; Technical Report No. II, pp. 15-22, May (1953); Technical Report No. III, p. 80, July (1954). CHAIKIN S. W., GLASSBR~~K C. I. and PARKST. D. (1953) An i~tru~e~t~r the co~i~~~ ~lys~sof ~t~~p~ric~~r~e. Abstracts, 123rd Meeting, Am. C&em. Sot., Paper No. 60, p. 2IB, Los Angeles. m S. W,, PARKST. D. and GLAZ+BR~~K C. I. (1956) Hydrogen Fluoride Detector. U.S. Patent 5741,544. CH..UKIN S. W., W~ZBUR A. C. and PARK~T.D. (1954) A~lys~ofpartic~~~te~or~e= Abstracts, 126th Meeting Am. Chem. Sot., Paper No. 24, p. lOB, New York. C&LECK D. J., Yotnva J. C, and GELMANC. (1955) Development of~~resce~ce quenching paper system far automatic detection of GB. Interim Report to Chemical Corps, Chemical and Radiological tabs, Army Chemical Center, Maryland,
A Shnplikd Fluorometric Fluoride Analyzer
259
C~~uss J. K. (1957) Stay of~res~t tape sensitive to ~y~~~~r~. Stanford Research Institute, D.R.C. Report, p. 20. FEXCX F. and Eh~¶c3 G. B. (1949) Analytic aspects of the chemical behavior of &hydroxyquiaoline Alrafvt. Chim. Actu 3,561--5X Iva! J. O., ZIBLENSKI L. F., THOR M. D. and THOWSON C. R. (1965) Atmospheric fluorometric fluoride analyzer. .I. Air PO&t. Control Ass. 15,195-197. THOMAS M. D., ST. JOHNG. A. and CELUICXN S. W. (1958) An atmosphericfluoride recorder. American Society for Testing Materials, Special Technical Publication No. 250, pp. 49-57. THOMPSON C. R. and IVIEJ, 0. (1965) Methods for reducing ozone and/or introducing controlled levels of hydrogen fluoride into airstreams, AL & W&. Polk&.Int. J. 9,799-805.
Environment, PerBamon Press 1967. Vol. 1, pp. 253-259. Printed in Great Britain.
A SIMPLIFIED
FLUOROMETRIC
FLUORIDE
ANALYZER
C. RAY THOMPSON,L. F. ZIELENSKI and J. 0. IVIE+ Statewide Air Pollution Research Center University of California, Riverside, California, U.S.A. (First received 30 October 1966 and in final form 23 January 1967) Ahstraet-A fluorometric fluoride analyzer previously described (Ivu? et al., 1965) has been redesigned and simplitied to provide a more usable instrument. A single photomultiplier tube is used to receive alternate light pulses rather than the two tubes used formerly. Illumination of the sensitized tape is accomplished by two ultraviolet lamps. The electronic circuitry for tape i~u~ation and carryiug of signals to the recorder has been simplified. A light “piping system improves light transmission and the bulk and weight of the overall equip~nt has been reduced to about one-half. INTRODUCTION
THE MEASUREMENT of hydrogen fluoride in the atmosphere in the fraction of microgram per cubic meter levels continues to be a problem. The Mini-Adak II recorder developed by ADAMSand KOPPB(1962) is advertised to measure as little as 0.3 pgfm3 when this level persists for 35 min. Con~ntra~ons lower than this can damage sensitive plants if present continuously; thus a means for recording these lower levels is needed. The fluorometric fluoride analyzer originally designed by Chaikin, Thomas and coworkers (CHAIKIN, 1952; CHAIKINet al., 1953; CHAIKINet al., 1954; CHAIKIN et al., 1956; THOMASet al., 1958) and later modified by IVIEet al. (1965), has the sensitivity required to measure these lower levels but has several shortcomings which have precluded its manufacture and general use. This analyzer samples the atmosphere through parallel warmed glass tubes, one of which absorbs HF in a thin coating of NaHCO,. The two airstreams are then drawn through adjacent portions of a paper tape impregnated with the magnesium salt of 8-hydroxyquinoline (CLAUS&1957), (FEIGL and HESSIG,1949) and (CHLECKet al., 1955). Gaseous HF quenches the fluorescence of the salt which is excited by an ultraviolet lamp. The difference in emitted light output is indicated on a strip chart recorder. EXPERIMENTAL The present anaIyzer uses the same kind of air sampling tubes as used previously and has heaters to maintain incoming air at temperatures 5-VC above ambient (FIG. 1). Heat is required to raise the air temperature above ambient and thus lower relative humidity because at near saturation the bicarbonate coating of the reference tube takes up water, dissolves, and as droplets has so little surface area that HF passes through the tube. Also, if water condenses on the clean tube HF will be absorbed and the differential between the two tubes will again be upset. At higher temperatures the air passing through the paper tape heats the Ghydroxyquinoline and inhibits its fluorescence. Raising the temperature of the air at the block to 64°C caused no loss of
* This investigation was supported in part by Public Health Service Research Grant AP 00244-02 from the Division of Aii Pollution, Bureau of State Services, Public Health Service. t Present address: Instrument Development Co., 11455 Newton Square South, Reston, Virginia 22061. 253
254
C. RAY THOMPSON, L. F. ZIELENSIU and J. 0. IVIE
response when the analyzer was sensing 0.14 pg/m3 of HF but at 71°C the response was completely inhibited. The electronic circuitry has been changed so that a single photomultiplier tube serves to receive the light from the sensitized tape rather than the two tubes used formerly. This eliminates two serious sources of trouble which arose when two photoSAMPLEINLET
t
SAMPLEINLET
Recorder
t
FIG.1, Pictorialdiagramof componentparts of fluorideanalyzer. multiplier tubes were required, the problems being caused by a great difference in the sensitivity of the two tubes with aging, and the length of time required to select and test a given pair of tubes. A large stock of tubes was required at all times, and several days of trial operation were often required to balance the output from two photomultiplier tubes in order to establish a zero base line. It was often necessary to change one or both tubes and then repeat the trial operation before two tubes with sufficiently equal sensitivity could finally be found. In the original instrument (THOMASet al., 1958) the light source for exciting the
A Simplified Fluorometric Fluoride Analyzer
255
fluorescence of the sensitized tape was a single U.V. emitting lamp. The lamp was lighted by a radio frequency voltage necessitating the use of a radio frequency oscillator. This has been eliminated and presently two U.V.emitting lamps are lighted by a less complex method incorporating a high voltage transformer to supply a stabilized voltage working directly off the commercially available a.c. power line. The high voltage output from the transformer is alternately fed to each of the two lamps through solid state rectifiers. A Leeds and Northrup synchronous converter is used to transfer the output from the photomultiplier tube to the reference and sampling measuring circuits in synchronism with lamp illumination (FIG. 2).
FIG. 2. Schematic diagram of fluorometric fluoride analyzer. Component parts identification of FIG. 2 Circuit reference
Description
Cl c2 c3, C4 C5, C6 C7, C8 C9, Cl0 Cll, Cl2 Cl3 c14, Cl5
Capacitor, Capacitor, Capacitor, Capacitor, Capacitor, Capacitor, Capacitor, Capacitor, Capacitor,
CRl, CR2 CR3, CR4, CR5, CR6
Diode, 1NlllO Diode, lN34A
E
6mfd, 600 V d.c. O.Smfd, 600 V d.c. O.OOlmfd,400 V d.c. O.OSmfd,400 V d.c. Smfd, 25 V d.c. 25mfd, 25 V d.c. 4Omfd, 140 V d.c.-Sprague TVA 2445 2.3mfd, 330 V a.c.-Leeds and Northrup No. 023126 2Omfd, 400 V d.c.
256
C.
RAY
THOMPSON,
Component
L. F. ZELENSKIand J. 0. Ivrs
parts identification
of Pro. 2 (continued)
Circuit reference
Description
Fl
Fuse, 2 amp
Kl K2 K3 K4 K5 K6 K7
Time Delay Relay-Amperite 115C15T Time Delay Relay-Amperite 115N015T Time Delay Relay-Amperite 115C3OT Time Delay Relay-Arnperite 115NO2OT Potter and Brumtield Relay KRPI 1A Photomultiplier Signal Transfer Relay-Leeds 354156 Clamping Block Solenoid-Assco No. 2X867
Ll
Filter Choke, 16h, 15 mA
Ml M2 M3
1 rev/min Tape Advance Motor-Dayton Mfg. Co. Type 4K807 Tape Advance Timing Motor-2 rev/hr Synchron Motor 1138RC12-60 Balance Motor-Leeds and Northrup No. 017138
PM1
Photomultiplier
Rl-R9 R10 Rll R12 R13, R14, R15 R16 R17 R18, R19 R20, R21, R22 R23, R24 R25, R26 R27 R28 R29 R30 R31 R32 R33 R34
Resistor, Resistor, Resistor, Resistor, Resistor, Resistor, Resistor, Resister, Resistor, Resistor, Resistor, Resistor, Resistor, Resistor, Resistor, Resistor, Resistor, Resistor, Resistor,
Sl s2 s3 S4 s5
Manual Tape Advance Switch Automatic Tape Advance Switch Recorder E+xnal “On-off” Switch Main Power Switch Scale Switch-Centralab No. 1401
Tl T2 T3 T4
High Voltage Transformer-Ultraviolet Variable Autotransformer-Superior Transformer-Triad R-7A Constant Voltage Transformer-Sola
Tube-Dumont
27OkQ 1/2W 33OkQ 1/2W 47OkQ 1/2W 15kn, 5W 4.7MR, 1/2W 5MQ 1/2W Ma, 1/2W lOkQ, 1W lOOkR, 1/2W 1OkQ 1/2W m, 1/2W 5wZ, 10 Turn-Spectral 84kQ rt lx, 1/2W 8kQ rf:lx, 1/2W 4kn, + 1%. 1/2W 2Kz, + lx, 1/2W lkn, + lx, 1/2W lKz, + lx, 1/2W 1OkQ 2W
and Northrup
No.
6467
Model 810
Products, Inc. Model XT-1 RIectrIc Co. Type 10 CVH-1
(Facing p_ 256)
A Simplikd Fluorometric Fluoride Analyzer Component parts i~tifi~~n
257
of Fro. 2 (~~
circuit rt!ference
Description
UVl, UV2
Ultraviolet Sources--Ultraviolet Products, Inc. Model llSG1
Vl v2 v3 v4
Electron Tube, 12AU7 Electron Tube, 6X4 Electron Tube,0A2 E%ctronTulE, OB2
.~
Because illumination of the sensitized paper tape gave diffused light for detection by the photomultiplier tubes, a new optical system was designed. A mirror arrangement in the older instrument which wasted much of the radiant energy was replaced by a truncated plastic cone which “piped” the light directly to the single photomultiplier tube. A narrow pass interference filter (Bausch and Lomb #44-7836) was used to isolate the 3650 A lightfrom the u.v. lamp which excited the fluorescence of the paper tape. This eliminated other visible radiation which appeared as “background” light on the sensing tube, An end window photom~tip~er tube which has a greater light collection efficiencyand minimized reflectance losses was substituted for the previously used side-window tubes. To check the efficiency of the new optical system a type 51 incandescent lamp, designed to be lighted by a 6 V source, was substituted for the U.V.source and the following tests were made with the analysers in their normal operating ~~~mtion but with the paper tape removed. The lamp was connected to a 1.5 V battery so that it was barely lighted. The voltage output from the photom~tip~er tube in the new system was 62 V. For the system using mirrors the output of the photomultiplier tubes was 0.36 and 0.26 V, respectively. A second test was performed with an International Rectifier Corp. type A5PL selenium photocell which was substituted for the photomultiplier tubes. In this trial, using the 1.5 V battery to ~u~nate the lamp, current output of the photocelI in the new optical system was 16 x IO-’ amp while output from the mirror system was 41 x lo-l2 amp. A repeat of this test but with a 6 V battery gave 6 x 10m6amp for the new optical system and 12 x lo-’ amp for the old. With the increased sensitivity it was possible to reduce instability caused by noise. Both bulk and weight have been reduced to about one-half that of the previous equipment (FIG.3). After the design of the analyzer was completed several weeks were devoted to checking tim=oncentration response of the instrument to standard hydrogen fluoride atmospheres. These atmospheres were prepared by rno~~g a very fine dust filter (HP-200, Dust Control, Inc.)* capable of removing particulate matter down to the 0.3~ range upstream from an HF dispenser. The rated capacity of this filter was about fifty times that at which it was operated, thus giving high filtration efficiency. Gaseous hydrogen fluoride was dispensed into the intake of a small squirrel cage blower which diluted the gas to the desired concentration (THOMPSON and Ivm, 1965).The gas came from a concentrated solution held at 0’ C. Gas concentration was varied by changing * Dust Control Inc., 1144 W. 135th Street, Chrden8, california
258
C.
RAY
THOMPSON, L. F.
ZIELENSKI
and J. 0. IVIE
the airflow being bubbled through the solution. Two air samples, one to an impinger, the other to the analyzer were drawn from the blower exhaust at the same point. Calorimetric measurement (BELLACK and SCHOUBOE, 1958) of fluoride in the impinger sample was used to calibrate the inst~ment (FIG. 4). The curve shows the linear regression of the recorder reading on fluoride content of the air samples as calculated by the method of least squares. Daily operation for several weeks showed it to be reliable in performance.
1
0.1
0.2
O‘S
0.4
0.5
Micto@uns FItwide per Cubic Meter
FIG. 4. Comparison of recorder response to increasing;~n~ntrations of HF as determined
cn~orimet~~lly.
~~n~w~e~e~~ts_The technical assistanceof KENNETHM. HOLTZCLAW and isgratefully a&now&edged.
EVELYN
E. LUNDIN
REFERENCES ADAMSD. F. and KOP~ER. K. (1962) A field evaluationof the mini-Ads II autonlatic fluoride air pollutant analyzer. J. Air PO&t. Control Ass. X2,164-169. BELLACK I.and SCHO~,~OE P. J. (1958) Rapid photometric determination of fluoride in water. Analyt. m
Chem. 30,2032-2034. S. W. (1952) C~nti~~o~~~oride analyzer. Stanford Research Institute Technical Report No.
I, pp. 21-31, August; Technical Report No. II, pp. 15-22, May (1953); Technical Report No. III, p. 80, July (1954). CHAIKIN S. W., GLASSBR~~K C. I. and PARKST. D. (1953) An i~tru~e~t~r the co~i~~~ ~lys~sof ~t~~p~ric~~r~e. Abstracts, 123rd Meeting, Am. C&em. Sot., Paper No. 60, p. 2IB, Los Angeles. m S. W,, PARKST. D. and GLAZ+BR~~K C. I. (1956) Hydrogen Fluoride Detector. U.S. Patent 5741,544. CH..UKIN S. W., W~ZBUR A. C. and PARK~T.D. (1954) A~lys~ofpartic~~~te~or~e= Abstracts, 126th Meeting Am. Chem. Sot., Paper No. 24, p. lOB, New York. C&LECK D. J., Yotnva J. C, and GELMANC. (1955) Development of~~resce~ce quenching paper system far automatic detection of GB. Interim Report to Chemical Corps, Chemical and Radiological tabs, Army Chemical Center, Maryland,
A Shnplikd Fluorometric Fluoride Analyzer
259
C~~uss J. K. (1957) Stay of~res~t tape sensitive to ~y~~~~r~. Stanford Research Institute, D.R.C. Report, p. 20. FEXCX F. and Eh~¶c3 G. B. (1949) Analytic aspects of the chemical behavior of &hydroxyquiaoline Alrafvt. Chim. Actu 3,561--5X Iva! J. O., ZIBLENSKI L. F., THOR M. D. and THOWSON C. R. (1965) Atmospheric fluorometric fluoride analyzer. .I. Air PO&t. Control Ass. 15,195-197. THOMAS M. D., ST. JOHNG. A. and CELUICXN S. W. (1958) An atmosphericfluoride recorder. American Society for Testing Materials, Special Technical Publication No. 250, pp. 49-57. THOMPSON C. R. and IVIEJ, 0. (1965) Methods for reducing ozone and/or introducing controlled levels of hydrogen fluoride into airstreams, AL & W&. Polk&.Int. J. 9,799-805.