:ibsence of monomer and after evtraction from monomer (Table 11). The straight-line plots are not suprrimposahle, lion ever. Thc datn obtaincd Iiy extracting inononwr containing up t o 0.0041% phenol n ere u s ~ das a calibration to calculate the recovrry of higher concentrations b y tliis p r o c ~ d u r e(Table 111). This shoixs that up to lY0 phenol in this nionomer can be determined. Concentrations higher than 1% were not inwstigated nor was an extensive precision study made. Table I1 shons the results of similar experiments n ith hIEHQ. Although thil relationship of concentration to absorbance is linear in both instances, it is unexpccted that, aftrr evtraction from the mononicr, the plot is higher than that M ithout extraction. S o further norh check n a s macle. The data are qufficient to denionstratr that, a i t h 1)roper standardization, a procedure can I>e u w i for h l E H Q based on this color reaction. Extractions a t highcr levels of M E H Q concentration--t, g. O.1Ycn r i p not attempted. Interferences. -4fen of the more obvious possible compounds which might he present in t h e monomer were chrcked for their effect, if any, on t h e color development. HIDROQUIGONB. A t equal co~iceiitration levels there is essentially no effect on the absorbancr of phenol-aminoantipyrine dur to hydroquinonc When
Table
II.
Concentration-Absorbance Data
Phenol Concn. No
monomer 7.25
72 X
1@
Extracted .Ilisorbance 0 105 0 140 10 0 220 21 0 270
14.5 29
0 440 0 570 0 890
41 58
MEHQ Concn., yo
x
19 5 25 57 5 T4
75 99
1oj -
0 0 0 0 0 0
138 238 378 588 488 765
~~
Table 111.
Concentration of Phenol in Monomer
Known, 6% 1 03 0 103 0 0103
Found. o ( 1 0% 0 102 0 0101
the ratio of hydroquinone to phenol is 10 to 1, the absorbance of phenol-aniinoantipyrine is increased by about 13%. The effect on hZEHQ-aniinoantipyrine n-as not checked but should be similar. DIPHEGYLPHESTLE?;EDIAJIINE is es-
sentially insoluble in water and is not extracted by base from the monomer. ~-HYDROXYDIPHEXL.MISE. This compound does react with the reagent to yield a color Tyhich absorbs in the same region as the phenol and MEHQ reaction products. ACKNOWLEDGMENT
The authors express gratitude for help in the completion of this investigation to V. P. DehIarco, E. J. Hyland, and C. T. Simpson. LITERATURE CITED
( 1 ) Clark, IT. RI., “Determination of Hydrogen Ions,” pp. 208-9, Williams &
\Tilkins, Baltimore, 1028.
(2) Dannis, M., Sewage and Ind. Wastes
23, 1516 (1951). (3) Emerson, E. I., J. Ory. Chem. 8, 417 (1943). (4) Ettinger, 11. B., Ruchhoft, C. C., Iishka, €I. J . , ~ N A L .CREII. 23, 1783 (1951). (5) Gottlieb, Sidney, Llarsh, Paul, IND. ESG.CHEX,.\SAL. ED. 18, 16 (1946). (6) Martin, It, IT., ASAL.CHEW21, 1419 f 1949). (71 Mohler, I:. F., Jacob, J. S . , Ibid., 29, 1369 (1957). (8) XIurray \I. J., I b i d . , 21, 941 (1949). (9) Riddle, ’E. H., “IIonomeric Acrylic Esters.” p. 221, Reinhold, Neiv York, 1954. (10) Smullin, C. F., 11-etteran, F. P., ANAL.CHEX27, 1836 (1955).
RECEIVED for review January 2, 1958 Accepted February 27, 1959.
Automatic Atmospheric Fluoride Pol utant Ana yzer DONALD F. ADAMS and ROBERT K. KOPPE Division of Industrial Research, The Sfate College of Washington, Pullman, Wash.
b Atmospheric fluoride pollution has been studied in many parts of the world in recent years, but no methods are available for the automatic, continuous determinations o f fluctuating, atmospheric fluoride levels. An instrument which produces a continuous, integrated record of the fluoride concentration for finite periods, consists essentially of a circulating fluoridesensitive reagent, continually brought into contact with freshly sampled air, and a recording flow colorimeter. Fresh reagent is programmed into the system on a preset time schedule which is automatically modified, if the accumulated fluoride concentration exceeds a predetermined level. Excellent correlation has been established between the automatic recorder and conventional sampling procedures.
A
fluoride pollution has been observed in many parts of the world during recent years. The increase in the numbers and types of industries utilizing fluorides and the expansion of industry into previously agricultural areas have been primarily reaponsible for the increasing attention given this pollutant. Fluorides occur naturally in nearly all minerals and living organisms Lon- concentrations are normally found in plants as a result of root uptake from the soil. Low levels in animal tissue result from ingestion of forage, minerals, and mater containing fluorides iii the normal concentration range. Ingestion of this ?lenient b y humans and animals nithin certain low limits has been reported to reduce the incidence of caries ( 6 ) . Hon-ever, excessive deposition of fluorides on plants or intake by aninialq may result in plant TMOSPHERIC
or animal fluorosis. This poisoning may be chronic or acute, depending upon length and sevcrity of exposure. Fluoric effluents h a w produced fluorosis in plants and animals in many areas. Determination of fluoride concentration in the atmosphere is therefore considered to be one step in the investigation of silspectrd contamination of plants or animals. The onlj available methods for the determination of fluoride in the atmosphere require sampling the air for several hours to several da) s to accumulate sufficient fluoride in a single sample for subsequent chemical analysis. Concentration levels of fluorides in the atmosphere ha\-e bern studied near knolvn emission sources in Washington (1, 6). I-tah ( 1 , 10, 11). and i,lseahere (8, 14). Thc datn indicate that the long-term average concentrations of VOL. 3 1 , NO.
7,JULY 1959
1249
Figure 2.
Figure 1 . Prototype dosimeter-recorder
of
automotic
fluorides in alleged fluorosis areas are in the concentration range of a few parts per billion or less. This type of sampling cannot. reveal the extremes in high and low concentrations which may exist for short periods during these long sampling periods. An urgent need exists for a n autmatic sampling and analyzing recorder with suflicient sensitivity t o indicate continuously the changes in fluoride concentrations in the atmosphere. Several difficult prohlcms are involved in the developmcnt of an automatic analyzer. Fluoride in the atmosphere is usually measured in parts per billion (or in micrograms of fluoride per cuhic meter), rhereas simultaneously occurring pollutants such as sulfur dioxide, oxides of nitrogen, nnd phosphoric acid mist may be measured in parts per hundred million or per million. Therefore, a satisfactory procedure must not only be extremely sensitive to thc presence of fluorides, b u t must have a high tolerance for the many interfering inns. Chaikin, Classbrook, and Parks, (7) reported the development of a laboratory model of an automatic analyzer for hydrogen fluoride, based on the photmetric measurement of the selective quenching of the fluorescence of magnesium oxinate by fluoride ions (1)). Contaminated air was drawn through a moving filter tape on jr-hich the fluorescent compound mas impregnated. The instrument is not commerically available. Thomas and St. John (f5) have recently presentrd a proeress
17.50
The Mini..Adak
ANALYTICAL CHEMISTRY
rcport on this instrumental procedure. I n 1956, Adams, Dana, and Koppe (t) reported on a prototype photometric laboratory fluoride analyzer for use with a liquid reagent. This pap-:r described a miniature working model of a prototype automatic dosimeterrecorder (S), Figure 1, which may be used for the determination of low concentrations of soluble, ion-producing fluorides in the atmosphere. The MiniAdak (Figure 2) can be used for the determination of the concentration of a,ny soluble ion-producing pollutant for which a colorimetric method of analysis exists or may be devised. Basically, i t may he characterized as a recording flow colorimeter in which the flow cell forms a n integral part of the air-reagent absorption system. As a fluoride analyzer, it photometrically measures and records the rate of reaction of zirconium-Eriochrome Cyanine R reagent with the concentration of soluble fluorides in a sampled air stream throughout a given sampling period. A time stainp may be substituted for the continuous recorder, if the analyzer is used to produce a dosimet,er-type record. EQUIPMENT
The Mini-Adak analyzer consists of two fnndamental components: a f l o ~ colorimeter capable of either driving a recorder (in the continuously recording. dosimeter model) or of triggering R time stamp upon the development of a photocell output equivalent t o some preselected concentration of the pollutnnt
41RREAGENT CONTACT
Figure 3. tactor
Details of air-reagent con-
absorbed in the reagent (in the strict dosimeter model), and an air-reagent contarting system in which a continuously circulating small volume of reagent reacts with the desired constituent from the air stream. The additional equipment making up the analyzer permits these fundamental components to carry on their function in a predetermined, automatic manner. Cycling a small volume of reagent with a continuously sampled stream of air for varying periods of time is fundamental to a liquid, chemical dosimeter-
SPDT +
m.
SEALED RELAY
TO
2
SADDLE VALVE
SOLENOID ($K
Ip.
Figure
COIL L U G S
5.
Schematic diagram of Mini
Adak automatic air po!lutant analyzer
,@ME-51
3
STANCOR
L
F S 8416
.L. 4
1-5
RELAY TERMINALS
WCTER
JONES P L U G
r: 6.3 V A G
CONNECTIONS
I - B L A C K - T O FLUID ELECTRODE
i
II~RED-TO
CONTROL ELECTRODE
IT[. SADDLE VALVE
Y
Figure
4.
T STORAGE
M
DRAIN VALVE
AIR
Liquid level control circuit
type analyzer. The principle pwiiiits concentration of extremely low concentrations of pollutants to a detectable level. The air-reagent contact system is designed to contact, a large volume of air with a small volume of continuously circulating reagent. The concurrent t'ype of contactor used is illustrated in Figure 3. A 15-ml. volume of reagent, is introduced into the upper portion of the flon- cell and drains slowly through the orifice a t the loiver end of the cell. The incoming air lifts the reagent up through the air-reagent contact column and discharges it into the top of the flow cell. The air is exhausted through the top by a n air pump. The contacted reagent then drains down through the flow cell, is measured photometricalljr. and re-enters the contact system. Continual aspiration of the reageiit with air will stcadily reduce the reagent volume through the process of evaporation. Such a volume reduction results in a change in the absorbance of the reagent. Therefore, an elect'ronic liquid-level control system (Figure 4) was designed to sense a droprise decrease in the reagent volume resulting from evaporation. I n addit'ion, the control system maintains the reagent at its initial volume by dropmise injection of make-up water through a Beckman Titrator solenoid valve as required by the evaporation rate. The complete schematic block diagram of this potentially versatile analyzer is shown in Figure 5. The MiniAdak utilizes a Photovolt Model 50111 c.lectronic phot,ometer with a Type E photocell to dptect and amplify the intensity of the light passing t,hroughthe flowing strenni of reagent. The Type E photocell is designed for improved light sensitivity a t ivave lengt,hs of light greater than 500 mp. A 75-n-attt 7 30-volt, clew incandescent, bulb provides the light source measurement9 within the visihle light region. An adjustable iris diaphragm permits t,he selection of light int,t:nsity as required by the reagent and the absorbance filter. A 556-mfi narrow-band p
filter is used when inaking fluoride measurements with the zirconiumEriochrome Cyanine R reagent. I n addition, the optical system is designed to permit fluorescent measurements to be made by substituting a mercury vapor light source and moving the photocell from 180' to a 90" position in relation to the light source. Pon-er stabilization to r t 0 . 5 ~ ofor the photometer system is maintained with a Ra) theon voltage regulator. The sampled air stream may be drawn directly into the air-reagent contact system or bypassed, b y means of toggle valves through a rotameter, during air flow nieasurenient and adjustment. Final adjustment of the air floir rate is made with an air leak valve located on the vacuum side of the airreagent contact system. T h e sampled air is drawn through the analyzer by means of a Gast vane pump. A motor-operated, 2-niinute1 singleiq-cle, multiple cam timer sn itch controls the sequencing of the various automatic operations of the analyzer during the reagent discharge-charge cycle. Table I shons a typical timing sequence. Under the dosimeter-type operational pattern, the detection of the attainment of the dose concentration of the polluta n t in the reagent triggers the dischargecharge cycle. Tn o additional discharge-charge controls are available for the convenience of the operator and to compensate for the nonideality of the reagents being uqed: a reset snitch to activate the discharge-charge cycle upon command and a 0 to 24 hour reset timer clocli. This third activation control was found necesqary, because the reagents tend to change optical character even nheri aspirated n ith clean air for periods over 24 hours or more. This lach of long-term reagent stability prevents operation of the analyzer as R dosimeter in the strict sense of the nord. Because it is conceivable that several days or more might elapse a t a given location without experiencing air pollution, a single nilunie of reagent
I
Table
I.
Time, Seconds 0 30 35 40
50 70 100 120
INTAKE
Sample-Changing Sequence
Recorder off Air pump off Dump valve opens Dump valve closes Rinse water on Rinse water off -1ir pump on Air pump off Dump valve opens Reagent pipet fill valve 011 Reagent pipet fill valve off Dump valve closes Reagent discharge valve opens Reagent discharge valve closes Air pump on Recorder on
would fade beyond usable limits during such an hypothetical sampling period. Therefore, the 0 to 24-hour reset timer clock initiates the discharge-charge cycle autoniatically a t the end of a predetermined sampling span, even if the dosimeter level of pollutant has not been accun~ulated within that time. I n practice, the fluoride analyzer may be operated for any desired sampling span up to 24 hours with the present reagent formulation. REAGENTS A N D THEIR PREPARATIONS
Selection of suitable reagents for the determination of pollutants in the atmospheie in a dosimcter-type analyzer must be based on the follon ing criteria: 1. Good sensitivity in the expected concentration range. 2. Conformity with Beer's lan within the limited conccntration range expected. 3. Noiiscnsitivity of the reagent to the evpected concentrations of the other ion-producing pollutants frequently found in association with the pollutant being studied. VOL. 31, NO. 7,JULY 1959
1251
/
30 25-
0
5
10
Figure 7. 400
450 500 WAVE LENGTH, mp
4. A minimum time required for the reaction to attain equilibrium. 5 . Reaction stability at equilibrium6. Low temperature coefficient. 7. Stability of the prepared reagent. 8. A high buffering capacity with relative insensitivity of the color reaction to small changes in pH. An extensive study of the many published analytical procedures for the fluoride ion indicated that the zirconium-Eriochrome Cyanine R method of Rfegregian ( l a ) conformed most closely to the above ideals. The Megregian reagent x;as first modified by reducing the suggested hydrochloric acid concentration by 50%. This decrease in acidity resulted in a significant increase in the fluoride sensitivity with no noticeable change in sulfur dioxide interference, time required to attain equilibrium, color change produced by the aeration loss of hydrochloric acid, etc. Foaming of the aerated reagent is controlled by the addition of a trace of Dolv-Corning Antifoam A Emulsion or GE Antifoam 60. Light absorbance measurenients throughout the visible range were conducted Iyith the modified reagent to determine the n'ave length of light at which the greatest fluoride sensitivity could be obtained. Figure 6 s h o w the spectral characteristics of the modified hlegregian reagent and reagent +20 y of added fluoride. A fluoride sensitivity of approximately 1% T per y of fluoride ion in 15 nil. of reagent was obtaiued in the 0- to 30-y range a t a wave length of 556 m p . STOCK DYE SOLCTIOS. Dissolve 1.800 grams of Eriochrome Cyanine R (National Aniline Co.) in distilled water and dilute t3 1 liter. ACIDIFIEDZIRCOSIUhI STOCK SOLUT I O ~ ~ .Dissolve 0.1308 gram of zir-
1252
ANALYTICAL CHEMISTRY
550
4
15 25 25 30 MhXOGRAMS 9 FLUORIDE
35
40
Fluoride calibration curve
Figure 6. Spectral characteristics of the modified Megregian reagent
conium hydroxide (or an equivalent zirconium nitrate) in 375 1111. of warm, concentrated hydrochloric acid (sp. gravity 1.19), cool, and dilute to 1 liter lvith distilled mater. FLUORIDE REAGEST. T O 500 nil. Of distilled n-ater, add 160 ml. of the acidified zirconium solution folloived by 160 ml. of the dye solution. Add 3 drops of Dow-Corning Antifoam A Emulsion and 3 drops of Laboratory Aerosol (Fisher). Dilute to 1 liter. Then transfer the prepared reagent to a storage bottle in the Mini-Adak analyzer and i t is ready for use. Calibrate the Mini-Sdak by introducing small increments of standard fluoride solution to the air-reagent contact cell, while aspirating clean air through the system, permitting the reagent to mix and evaporate back to its original volume. Add more qtandard fluoride until a total of 30 y of fluoride has been added. A calibration curve as illustrated in Figure 7 is thus obtained. Atmospheric concentrations of fluorides in terms of micrograms per cubic meter of hydrogen fluoride may then be calculated, for any desired time span, during a given reagent cycle by dividing the total micrograms found by the cubic meters of air sampled during the qelected study period. Atmospheric fluoride sensitivity, under the present operating conditions of reagent. air sampling rate of 1.0 cubic foot per minute, and air contsctor-flow cell, is best expressed as the product of the fluoride roncentration (micrograms per cubic meter) multiplied by the length of the sampling span (minutes). Any combination of micrograms per cubic meter and minutes Jvhich yields a product of 30 is detectable. An average concentration of 0.5 y per cubic meter of hydrogen fluoride would be detectable, if present for a period of GO minutes. Likewise, a concentration of 30 y per cubic mcter of hydrogen fluoride would be detectable if present for 1 minute. Further increases in the
fluoride sensitivity of the Illirii-Adak now appear to be primarily dependent upon modifications of the air contactorf l o ~cell designed to permit greater scrubbing rates viithout producing mechanical loss of reagent. COMPARISON OF MANUAL A N D INSTRUMENTAL ANALYTICAL PROCEDURES
Previous studies of the fluoride content of ambient air and fumigation chamber atmospheres utilized fritted disk absorption toL\ers ( 1 , 6) to collect the fluorides for subsequent chemical analysis. Comparisons n-ere made between abborption samples obtained with two independent fritted scrubbing towers to determine the standard error of estimate between duplicate samples collected in the same manner. Test chamber atmospheres in the concentration range of 0.75 to 35 y per cubic meter of hydrogen fluoride were drawn through the two scrubbing toivers a t a rate of approximately 1 cubic foot per minute. The absorbing liquid x a s 150 ml. of 0.01N sodium hydroxide. The volume of air passing through each tower I\ as measured with a dry test floa meter ( 5 ) . The fluoride content of the absorbing liquids was determined by thorium nitrate titration (4). The standard error of estimate of duplicate samples was found to be =k0.73 y per cubic meter of hydrogen fluoride. Comparisons were then made between duplicate samples analyzed chemically (A. Table 11) and obtained from the Mini-Adak air-reagent contactor (B, Table 11). The latter scrulibinq device circulated 15 ml. of 0.OlN podium hydroyide for each sampling period. Thv volunie of the absorbing liquid lvas maintained automatically by the Mini-Adak liquid level control sy;.teni. The analytical procedure and the concentration range of hydrogen fluoride in the t e 4 atmospheres viere the same as in the previous comparison. The Ftnndnrd rrror of estimate on 24 5ampleq
I
I
O I L
1
1
- ’
I
I
.I,
1
PRECIPITATION
WIND SPEED WIND DIRECTION’,
I JUNE, 1957
Figure
8.
Atmospheric fluoride and meteorological data
was found to be *0.86 y per cubic meter of hydrogen fluoride. A comparison was made between the chemically analyzed sample. obtained with a fritted glass scrubbing toner and the automatic record of the Adak analyzer. The standard error of estimate of 11 duplicate samples n a s found to be +0.82 y per cubic meter of hydrogen fluoride. -4 similar coraParison between chemically analyzed samples from a fritted glass scrubbing tower and the automatic record of the Mini-Adak analyzer showed the standard error of estimate on 27 samples to be 10.68 y prr cubic mettr of h\ drogen fluoride. The statistical data for the four comparisons are tabulated in Table 11. Although there are some slight numerical differences betveen the observed standard errors of the estimates obtained from the four comparisons, application of the F test for sign;ficant differences indicates that the F ratio for all of these coiiiparisons is much less than that required to indicate significant differences a t the 5y0 lexel. Thus, it may be concluded that there are no statistically significant differences betn-een the obtained concentrations of hydrogen fluoride test chamher atmospheres- when automatically and continuously recorded with the Adak and Mini-Adak analyzers and the data obtained hy the more conventional procedure involving long term sampling with a n absorption toirer, followed by laboratory cheniical :tnalysis of the absorption solution. FIELD PERFORMANCE AND RESULTS
The original large model prototype Adak analyzer constructed under contract to the Community h i r Pollution Program of tht. S Public Health Service n as used continuously 111 field and laboratory studici for 5 months. Various components vf this anal) zer \\ere, honcver, in scrvice up to 18 months, in some instances. tliiring the timcl in ~ l i i c hthe arialyzer was developed from a manually operated. laboratory bench model t o the final, fully automatic assembly. Throughout the field testing program the Adak n a s mounted in a mohile ficld labora-
r.
b F i g u r e 9. T y p i c a l Mini-Adak record on filtered air and sulfur dioxide
tory, and was transported over roads varying in condition from dirt, ‘ k a s h board,” and new constructioii to concrete pavement. Approximately 1400 miles of roads nere covered in the course of the test period. An occasional loose nut or connection n as encountered. Homver, no serious component malfunctioning resulted from the continuous vibration of transporting the instrunient in this manner. The large d d a k was field-tested in the immediate vicinity of a n alumina reduction plant for a period of 13 days, in June 1957. During this period several short periods of ground lex el fumigation by fluorides n ere encountered. These pollutant encounters \yere well correlated n-ith the meteorological conditions. The Adak was adjusted so as to sample the air for 4 hours
using a single volume of t’he fluoridc reagent. At the end of each 4-hour period the reagent was automatically discarded and a new volume was injected. The data obtained during this sampling period are sumniarizod in Table 111. The maxiinurn concentration tlrterinined during the entire sampling period \vas 03 y per cubic mctw of hj-drogen fluoride and the niininiuni has been reported ns “zero” or undetectable. Thcse lat’ter periods are not individually reported in Tal~lc111. This, hon-ever, was the observed ntmosplieric fluoride concentration for all samplci: from S o . 1 through KO.66, with the exception of those portions of the 66 samples specifically reported in Table 111. The same data are yraphically presented in Figure 8. The ai-erage concentration for the, 1 M a y VOL. 31,
NO. 7,
JULY 1959
1253
period as 0.275 y per cubic meter of hydrogen fluoride. This value agrees closely with the averaged data obtained by investigators who have aspirated estcnsive series of liquid absorption samples for periods of several hours to scveral days (1, 10, 11, 14). Study of the possible effects of other pollutants upon the fluoride reagent has becn limited to sulfur dioxide and phosphates. Figure 9 s h o w a typical curve obtained with the Adak analyzer sampling an atmosphere containing 0.5 p.p.m. of sulfur dioxide. Continuous sanipling of an atmosphere at this concentration for 24 hours did not produce a detectable reagent color change. The addition of phosphorus pentoside
Table II.
up to 200 y did not result in a detectable change in the 15 ml. of reagent. CONCLUSIONS
The results of laboratory and field sampling have been reported. The standard error of estimate of laboratory atmospheres of hydrogen fluoride in the concentration range of 0.4 to 35 y per cubic meter sampled by the autoniatic analyzer and conventional absorption procedures followed by chemical analysis in the laboratory show no statistically significant differences betneen the tn o methods. Continuous concentrations of sulfur dioxide a t 0.5 p.p,m. and n phosphorus pentoside to
Statisfical Comparisons of Manual and Instrumental Methods of Air Ana lysis
Standard Error of Estimate, -,/CU. M. H F
Sources of Variation Duplicate fritted glass scrubber towers, A It0.73 Fritted glass scrubbing tower us. Mini-Adak concurrent scrubber B (analvzed chemically) It0 86 Fritted glass scrubbing tower us. automatic Adak recordings, C 10.82 Fritted glass scrubbing tower us. automatic Mini-Adak D f O 68 A us. B A us. C A vs. D No statistically significant difference.
NO.
F,Ratio
Value of F for Significance at 5y0 Level
... . .
11
27
ACKNOWLEDGMENl
The authors are indebted t o Lloyd Craine for the design of the liquid level control system. Development of the large prototype analyzer (3) was accomplished under contract 66512, Conimunity Air Pollution Program, Public Health Service as authorized under Public Law 159. REFERENCES
14 24
fluorine ratio of 7 to 1 are tolerated by the fluoride reagent. Additional study n.ill be required to determine the permissable concentrations of other pollutants which may be concurrently prcsent in a fluoridepolluted atmosphere without producing interference. No work has yet been done to determine the dpgree of rcaction of the fluoride reagent in the presence of particulate fluoride pollution, such as submicron cryolite fume or rock phosphate dust.
...
1,37O 1.24a 0.8@
...
2.13 2.61 2.03
(1) Adams, D. F., unpublished information, Longview and Tacoma, Wash.; Salt Lake and Utah Counties, Utah. (2) Adams, D. F., Dana, €1. J., Koppe, R. K., hleeting of Instrument SOC. America, Xew York, N.Y., September 1956. (3) Adams, D. F., Dana, H. J., Kop e R. K., “Re ort on the Universal xi: Pollutant k h y z e r , ” U. S. Dept. Health, Education, and Welfare, Sept. 4. 1957. (4) Adams, D. F., Koppe, R. K., ANAL. CHEM.28, 116 (1956). (5) Adams, D. F., Mayhew, D. J., Gnagy, R. hf., Richey, E. P., Koppe, R. K.. Allen. I. W..Znd. Ena. Chem. 44 1356 (1952). ’ (6) Arnold, F. A., Dean, H. T., Knutson, J. W., Public Health Repts. ( C . 8.) 68, 141 (1953). (7) Chaikin, S. W., Glassbrook, C. E., Parks, T. D., Divpion of Analytical Chemistry, Symposiiim on Air Pollution, 123rd hleeting, ACS, Los Angeles, Calif., April 1953. (8) Cholak, J., “Air Pollution Handbook,” hIcGill, P. L., Holden, F. R., Ackley, C., eds., pp. 11-23, McGrawHill, New York, 1996. (9) Feigl, F., Heisig, G. B., Anal. Chim. Acta 3, 561 (1949). (10) Greenwood, D. A., Call, R. A., Hales, J. V., Kesler! J. P., “Effect of Atmospheric Fluorldes 011 Man,” Summary Technical Report IV, U. S. Dept. Health, Education, and Welfare, 1957. i l l ) Hill. C. A,., Drivate communication. . 1958. ’ (12) RIegregian, S., ANAL. CHEM. 26, 116 (1954). (13) Xielsen, H. M., Ibid., 30, 1009 (1958). (14) Snowball, A. F., private communication, 1957. 115) Thomas, M. D., St. John, G. A., Society for Testing Materials, Boston, Mass. June 1958. -I
Table 111.
Compilation of Periods in Which Concentrations of Hydrogen Fluoride Air Pollution W e r e Recorded
(Continuous automatic fluoride air sampler located a t Mead Substation, Spokane, Wash., June 5 to 18, 1957“) AV. y /
Individual Portion of Cu. M. H F Samnlinn Samnline Period for Portion ing BF Hourp of Samule Sequence Period,’ H o b Shon -. Wind Shoir iAg Date Sample Time, Time, Time, Time, Direction HFb Start NO. start finish start finish NW-NE 7.1 2 6/5/57 1745 1950 1745 1050 93 1945 1950 2aCzd N-NE 0.7 3 1955 0025 1955 0025 _... .. ~ . ~. NW-NE 1.1 6/7/57 9 2119 0139 2149 0139 N W-E 1 4 6/12/57 1400 1815 1600 1815 31 NW-NE 4 5 32 1815 2200 1815 2200 X-NE 7 3 2200 0015 2230. 0015 33 50 5 6/13/57 33a. 0010 0015 NE 1.3 6/16/57 53 0528 0930 0625 0930 K-NE 3 4 0.525 0925 0925 6/17/57 . _ ~ ._ . ~ . 0525 59 117-E 0.5 60 0925 1200 0925 1200 SE 1.2 1600 2000 1815 2000 62 0 3 2000 2400 2000 2400 NE-SE 63 0400 0800 0615 0800 NE 0.5 65 6/18/57 Sampling continued from 1345, June 5 until 1028, June 18, 1957. 66 consecutive Pamples of appro\imately 4-hour duration each were obtained. Automatic analyzer is essentially a continuous recording dosimeter which recorded illcrease in fluoride accumulated from a continuously sampled stream of air during a 4hour period. Then fluoride-sensitive reagent was automatically dumped and a fresh volume of reagcnt introduced into the instrument. Calculations for samples 2 and 33 for short periods during sampling cycle showed much higher than average fluoride level. These 5-minute concentrations have been cnlculated and reported as 2a and 33a. Sample 2a indicates 93 7/m3 H F for period 1945 to 1950 hr. on 6/5/57. Average for entire period (1i45 to 1950 hr.) was 7.1 y/m3 HF. In sample 2 amount of fluoride accumulated bv analyzer was so great that deterting reagent was completely reacted before completion of 4-hour sampling cycle. Instrument automatically dumped this spent reagent and intxoduced a new volume of reagent. ~
1254
ANALYTICAL CHEMISTRY
~
RECEIVEDfor review January 31, 1958. Accepted February 9, 1959. Division ot Water, Sewage, and Sanitation Chemistry, Symposium on Air Pollution, 134th Meet ing, ACS, Chicago, Ill., September 1953.
