Anal. Chern. 1982, 5 4 , 1015-1017
(8) Anderson, J. E : Bagchi, R. N.; Bond, A. M.; Breenhiii, H. B.; Henderson, T. L. E.; Walter, F. L. Am. Lab. (Fairfield, Conn.) 1981 (Feb), 21-32. (9) von Wandruszka, R. M. A.; Maraschln, M. Anal. Lett. 1981, 74, 463-478. (lo) Anderson, J. E:.: Bond, A. M. Anal. Chem. 1981, 5 3 , 1394-1398. (11) Woodard, F. E ; Woodward, W. S.; Rellley, C. N. Anal. Chem. 1981, 53, 1251 A-1266 A. (12) "TRS-BO Model I l l Operation and BASIC Language Reference Manual"; Radio Shack: Ft. Worth, TX, 1980.
10'15
(13) Titus, J. A. "TRS-80 Interfacing"; Howard W. Sams & Co., Inc.: Indianapolis, IN, 1979;Book 1, Chapters 1-3.
RECEIVED for review October
16, 1981. Accepted February 8, 1982. This work was supported by the National Science Foundation Grant 77-06911 and by the School of the University of Louisville.
Chemililminescence Measurement of Atmospheric Ozone with an Oil-Coated Paper Filter Fumltake Chisalka" and Shigeru Yanagihara Mechanical Engineering Laboratory, 1-2 Namiki, Sakura-rnura, Niiharl-gun, Ibaraki, 305, Japan
Sensitive chemiluminescence techniques have recently been developed to monitor ambient ozone concentrations. The Nederbragt et al. technique (1) for ozone monitoring is based upon the chemiluminescence light produced in the reaction between ozone and ethylene. Ethylene is combustible and toxic. In addition, it polymerizes in the gas flow system, thus causing difficultiles with flow meters, regulators, and needle valves. As air filters resolve ozone molecules, a useful UV absorption ozone monitor is disturbed by fine paticulates in air. An ozone detector using chemiluminescence from the reaction of ozone with polymers such as poly(tetraflor0ethylene) and polyethylene has also been developed by Neti et al. (2),but this device has not been tested as an urban ozone monitor. As a very useful and sensitive tecnique, the chemiluminescent reaction between peroxyacetyl nitrate (PAN) and ozone with trieth!ylamine vapor, developed by Pitts et al. (3), can be used to monitor these atmospheric concentrations. Our supplementary examination of the method has been carried out by using a common cellulosic paper fiiter impregnated with liquid triethylamine. Our reexamination of the method with particular attention being paid to the stability of the vaporization of triethylamine led to our discovery of chemiluminescence in the reaction of ozone with oil-coated paper filters. This reactive paper filter is prepared by impregnating common cellulosic paper filter with a common lubrication oil. As an application of this phenomenon, a prototype atmospheric ozone monitor has been constructed and tested. Only cellulosic paper filter shows the effect, and the light which occurs on the surface of the reactive paper filter has not yet been phytiically accounted for. But, we have found that the results of some measurements on the characteristics of the chemilumiinescent light are as follows.
EXPERIMENTAL SECTION Apparatus. An experimental counting system for the light emission from the ozone-oiled paper filter reaction has been constructed that allows for convenient change in experimental conditions such as a sample gas flow rate, reaction pressure, and the exchange of suitable light filters. A schematic view of the experimental apparatus is shown in Figure 1. A sample gas to be monitored enter13 a reaction vessel (101 mm i.d., 1.3 L volume, stainless steel) through a sampling pipe (10 mm o.d., 8 mm id., curved stainless steel pipe 200 mm long for blocking room light, and Teflon pipe tubing) and a glass nozzle. Ozone molecules in the sample gas colllide with the reactive oiled paper filter, impregnated with 1 rnL of a common lubrication oil, and a chemiluminescence reaction takes place. The curved head of the nozzle is perpendicularly centered above the paper filter. The sample flow is maintained Iby a vacuum pump and regulated by a valve. The light is emitted through an Pyrex glass window and a light
filter and detected by EL photomultiplier tube (PMT, Hamamatsu TV R464, -1000 V). A thermoelectric cooler at -20 "C was used to stabilize the PMT dark count. The signal is fed into a photon counter device. Procedure. To being an experiment, we secured the reactive paper fiiter to a filter mount and inserted the nozzle into an O-ring fitting connector. The characteristics of used cellulosic paper filter were double acid wash grade No. 2 in JIS standard, 90 mm in diameter, 0.26 mm in thickness, and 115 g/m2 in weight, made by Toyo Roshi Corp. The pressure in the vessel and sample gas flow rate are typically 460 torr and 1.2 L/min, respectively. All experiments were performed at room temperature 21 & 0.5 OC. Blank values for the photon counting were obtained by using synthetic dry air (02/N2= 1/4). As samples of known concentration, the dry air was ozonized (maximum 0.2 ppm (v/v)) by a Bebdix photolytic ozonizer, and concentrations of ozone were measured by a conventional ozone monitor (Model OX-21, Kyoto Denshi Corp., chemiluminescent method using ethylene). For most experiments, photon counts were accumulated for 10 ti.
RESULTS AND DISCUSSION Emission Spectrum. The corrected spectrum of the light from the reactive filter impregrated with spindle oil (Instrument Oil) was obtained in the range from 300 to 600 nm. The relative intensity distribution of the spectrum is shown in Figure 2. The intensity was measured with five light filtem (UV-D2, KL-400, KL-450, KP-500, and KL-550; made b y Toshiba). The corrected relative spectrum Ir, of the light for wavelength =400 nm can be obtained by using three relativle factors Pr,, Frx, and Crf,: Irx = CrfxPr,/Frx (relative value for 400 nm), where Pr, is the relative response of the phototube, Fr, is the relative integrated transmission ratioed to the bandwidth of each light filter, and Crf, is the relative intensity of photon counts obtained for each light filter, respectively. The spectrum thus obtained has two peaks near 400 and 500 nm. The sensitivities to ozone for no filter and three filters UV-D2, Y-44 (Toshiba) and KL-400 are 136.9,25.2, 99.7, and 15.0 s-l-ppm-', respectively. Effect of Sample Flow Rate and Reaction Vessel Pressure. The sample gas supply and total pressure in the reaction vessel are variable quantities and depend in large measure on the shape of the glass nozzle head. The absence of an appreciable change in these quantities is a necessary prerequisite for a uniform light intensity in the vessel and a linear response from the detector. Four glass nozzles were prepared by drawing a heated glass pipe (4 mm i.d., 6 mm 0.d.). For each nozzle, experiments were run in triplicate to demonstrate the feasibility of a nozzle such that the response was not measurably affected by very small changes in the relative position of the nozzle with respect to the filter paper.
0003-2700/82/0354-1015$01.25/00 1982 American Chemical Society
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ANALYTICAL CHEMISTRY, VOL. 54, NO. 6, MAY 1982
-1
LIGHT FILTER
Oil No.
21
-40
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'i
e 3
2 - 0 O 03 (PPm) Flgure 1. Chemiluminescence detector.
-06-
'
I
Flgure 4. Comparison of sensitivities and linearity of ozone responses
'4,
~
to six kinds of oil: (1) Global Matic Oil (Bcycie engine, Kyodo Sekiyu), (2) Sonic Turbine Oil (pressure system, Kyodo Sekiyu), (3) Sunway Gokl MS-DG 30 (vehicle engine, Kyodo Sekiyu), (4) Neovac (high-vacuum system, Matumura Seklyu), (5) Barrel Freeze 46s (refrigerator, Matumura Sekiyu), (6) Instrument Oil (machine, Esso Standard).
- O" YO0
400 503
600
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15th.Octo !1979
"26th,Octo
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Wavelength ( n m )
Flgure 2. Emission spectrum of the chemllumlnescence reaction of oikoated paper fitter with ozone. Relative intensity maximum arbitrarily set at unity.
- 0.1
}27th,Octo.
30th,Oc:o.
I' Zth. Novmber
7
Flgure 5. Comparison of daily atmospheric ozone concentration measurements from this work and a conventional ozone monitor at an urban area in Japan. Flgure 3. Relations among response to ozone content, pressure in reaction vessel, and sample flow rate.
Consequently, in the case of an optimum nozzle, the repeatability of the measurement was within 3%, while for the others the variations were in the range 10-20%. Further experiments utilized the good nozzle. Relations among the detector response, sample flow rate, and the total pressure are shown in Figure 3. The response curve has a gentle peak at around 560 torr. The flow rate is saturated a t lower than 360 torr. The response falls a t the region of the saturated flow rate because the sample flow velocity in the nozzle head becomes sonic and ozone may be easily decomposed. In order to function most effectively, the flow velocity must be lower than the sonic speed. For highest sensitivity, a total pressure of 460 torr and a flow rate of 1.2 L/min were selected. Linearity of Response and Sensitivity to Different Kinds of Oil. For six kinds of oil, Figure 4 gives plots of the detector response. The responses are extremely linear with ozone concentration over the range from 0 to 0.19 ppm. The responses for No. 1-No. 6 oils are 217.1, 59.8, 101.9, 0.0, 40.0, and 136.9 s-l-ppm-l, respectively. The minimum response obtained is approximately zero for No. 4 oil and the No. 1oil provides the greatest sensitivity. However, the scatter of No. 1oil response is larger than the scatter for other kinds of oil. No. 6 oil provided the second best sensitivity. Therefore, No. 6 oil response coincides with the objects of this work. In the case of No. 6 oil, the limit of accuracy on the photon counting is 0.1 s-l for the scatter caused by the dark reaction when employing the dry air. Accordingly, concentrations of ozone as low as 0.001 ppm were detectable with the detector so that the response was 1.369 s-l for 0.01 ppm ozone. Generally, it is clear that the response to automotive engine or spindle oil is strong and refrigerating machine oil is weak. The linearity
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- 006 a Q
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vO
0 0 2 004 006 0 3 8 OX-21 O3 Monitor (pprn)
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Flgure 6. Relationship between readings of this detector and ozone
concentrations by the conventional ozone monitor.
and sensitivity of the detector thus appear quite satisfactory for its use as a monitor of ozone in atmospheric air. Effect of Other Air Constituents on Detector Response. Blank values for the photon counting apparatus were obtained by using the dry air. After these measurements, atmospheric air containing added ethylene to remove ozone was passed into the reaction vessel. The resulting photon count rate was less than 0.1 s-l, This air contained at least of 500 ppm C02, 60% saturation H20, and 1% CzH4. Responses were also lower than 0.1 s-l for 10 ppm ethyl nitrate, 10 ppm NO, 9.8 ppm NOz, about 10 ppm HCOOH, about 8 ppm HCHO, about 8 ppm SO2, and nearly 10 ppm PAN (generated in the sample of 100 ppm ethyl nitrite with the irradiation of UV rays ( 4 ) ) ,respectively. Consequently, it can be considered that there is no significant interference from these substances (except for HzOz,we have no information). These results were obtained by using no light filter. Demonstration of the Feasibility of This Method. After calibration with samples of known concentration, ozone in air
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Anal. Chern. 1982, 5 4 , 1017-1018
may be continuously monitored. Daily measurements oE ozone concentrations in urban Tokyo by this method and by the conventional ozone monitor OX-21 are compared in Figure 5. Consequently, the emphasis of this work will be placed on utilizing the cliemiluminescence as a possible ozone monitor. The two methods are almost in perfect agreement. As can be seen from the data of October 15th in Figure 6, both detectors agreed to within about f0.005 ppm. The scatter in these data is approximately independent of ozone concentration. This scatter can be reasonably attributed to fluctuations in blank count. Accordingly, the largest cause of the scatter is ithe instability of the dark count from the photomultiplier tube. Therefore, in the case of ambient air monitoring, the approximate limit of the detector is below 0.01 ppm (10 ppb). And these results are obtained with only one reactive paper filter. The variation of the response of this reactive filter to standard Ozone was within i3% for 3 months. Finally, work describing the more reactive paper filter treated with ultraviolet rays will be published in the near
future. At the same time, and from the more practical point of view, a compact design of this system should be investigated.
ACKNOWLEDGMENT Sincere thanks for encouragement and advise on this work are due to I. Shimada of the Mechanical Engineering Laboratory and John W. Birks of Max-Planck-Institut, LITERATURE CITED (1) Nederbragt, C. W.; Van der Horst, A,; Van Duijn, T. Nature (London) 1065, 206, 87. (2) Neti, R. M.; Riives, J. A. An Official Report of Japan Patents-Public Notice-3106, ‘1978, 229; Priority U S A . Patent-375481, 1973. (3) Pitts, J. N., Jr.; Fuhr, H.; Gaffney, J. S.; Peters, J. W. Envron. Scl. Techno/. 1973, 7 , 550. (4) Stephens, E. R.; Burieson, F. R.; Cardiff, E. A. J . Air Pollut. Control Assoc. 1065, 15, 87.
RECEIVED for review December 10, 1981. Accepted Februaqy 12, 1982.
Cotton-Acid-Succinate Separation of Controlled Substances Prior to Determination by Infrared Spectrometry Hlromltsu Kanai, * Veronica Inouye, Reginald Goo,’ and Helen Wakatsukl Chemistry Section, )Laboratories Branch, Hawaii State Department of Health, Honolulu, Hawaii 968 13
Many drug samples submitted t o our laboratory require separation of the controlled substance before identification can be made with a conventional method such as the infrared (IR) spectrometry. Methods routinely used to effect this separation include column chromatography, thin-layer chromatography (TLC), ion-pair extraction, ion-exchange chromatography, and acid-base extraction. The TLC separation is often disadvantageous because of its inability to separate effectively the milligram quantities of substance often needed for IR spectral analysis. As Coates (I)stated, the conventional IR instrument based on the optical null system of measurement is not ideally suited for microsampling due to the level of instrument response at low levels of transmittance. Although both the ratio recording and Fourier transform IR spectrometers are ideal for microsampling, they are very expensive for a routine laboratory. Because of the minute sample size and the time involved, column chromatographic separation is not suited for our laboratory. There have been studies on the separation of pharmaceutical amines based on ion-pair extraction (2,3)and ion-exchange chromatography ( 4 ) . In these methods, the mixtures for separation are in Lhe aqueous phase. Furthermore, certain basic drugs are extracted into the organic phase under both acidic and basic conditions. We wanted to study a method in which, following the initial drug screening procedure such as the TLC and ultraviolet (UV) spectrometric analysis, a milligram quantity of the controlled substance can be separated by applying the chloroform extract of the drug directly on the chromatographic column for IR identification. Histamine in fish is separated from other substances by passing the benzene-butanol extract through the cotton acid succinate (CAS) column and then eluting with 0.4 1\;1 sulfuric acid solution (5). This article IPresent address: Department of Public Works, City and County of Honolulu, Honolulu, HI 96813. 0003-2700/82/0354-1017$01.25/0
attempts to describe our studies on separating some of the controlled substances from mixtures using the CAS column.
EXPERIMENTAL SECTION Reagents. Caffeine, diazepam, phenacetin, paracetamol, and theophylline were obtained as pure free form. Doxylamine was obtained as succinate salt. Chlorpheniramineand pyrilamine were obtained as maleate salt. Codeine, ephedrine, and DL-amphet. amine were obtained as sulfate salt. Phenylpropanolamine, diethylpropion, pyribenzamine, m-methamphetamine, mescaline, fenfluramine, phenmetrazine, phentermine, procaine, cocaine, methaqualone, and oxycodone were obtained as salt of the h y drochloride. After vacuum evaporation, appropriate quantities of these standards were weighed so that extracted standards in chloroform was 15 %/I&. Dilutions were made with chloroform. Prepartion of CAS ( 5 ) . Ten grams of anhydrous sodium acetate, fused just before use, and 80 g of succinic anhydride were dissolved in 500 mL of acetic acid contained in a 1000-mL boiling flask. Twenty grams of absorbent cotton, cut into strips, wab, immersed in this solution. A condenser was attached and the contents of the boiling flask were refluxed for total of 48 h. The cotton was washed with tap water, hydrochloric acid (1+ 9),tap water, distilled water, and finally ethanol. The CAS was dried in a vacuum oven for 6 h at 100 OC. We have found that the CAS is stable for at least several years. It can be reused several times by washing shortly after use in the same manner as above. Instrument. UV spectra were recorded on a Beckman Model DK-2A spectrometer. IR spectra were obtained on a Perkin-Elmer Model 467 spectrometer with reflecting beam condenser attachment. CAS Column. A polypropylene column whose overall length is 5 in. and capacity of 7 mL was used. A 30-mL reservoir was fitted to the column. A 0.5-g portion of CAS was weighed and tightly packed into the polypropylene column. Procedure, Recovery Studies. One milliliter each of 3.0 mg/mL standards listed in Tables I and I1 was transferred to a set of CAS tubes marked I and another set marked 11. The set of CAS columns marked I was washed with 20 mL of chloroform and then washed with 20 mL of distilled water. After each washing, the column was blown out with nitrogen. The other set 0 1982 American Chemical Society
