2856
Anal. Chem. 1984, 56,2856-2860
samples can be analyzed harmlessly. Finally, in the case of ceramic material, the method is particularly suitable because of its nondestructive character.
ACKNOWLEDGMENT The assistance of the operation personnel of the Tandem Van de Graaff in Zurich and of the Reactor in Geneva is gratefully acknowledged. We also thank the Laboratoire de CBramiques, SFIT-Lausanne, for providing us with the ceramic samples. Registry No. A1,0,, 1344-28-1; sulfur, 7704-34-9; ferromolybdenum alloy, 11121-95-2;copper, 7440-50-8; steel, 1259769-2.
LITERATURE CITED (1) Ames, S. L. J . Appl. Phys. 1979, 4 1 , 1032-1034.
(2) Siivermann, L. “The Determination of Impurities in Nuclear Grade Sodium Metal”; Pergamon Press; Oxford, 1971; Intnl. Ser. Monographs 44. (3) Csikai, J.; AiJobori, S. M. J . Radioanal. Chem, 1979, 5 3 , 225-231. (4) Swlnehart, B. A,; Yao-Sin Su. Am. Ceram. Soc. Bull. 1983, 62, 70 1-703.
(5) Albert, Ph.; Biouri, J.; Cleyrergue, Ch.; Deschamps, N.; Le Hericy, J. J . Radloanal. Chem. 1988, 1 , 297-311, 389-396, and 431-441. (6) Engelmann, Ch. CEA-Rep. 1984, No. 2259. (7) Debrun, J. L.; Albert, Ph. Bull. Soc. Chim. Fr. 1989, 1017-1020. (8) Thomas, J. P.; Schweikert, E. A. Nucl. Instrum. Meth. 1972, 9 9 , 46 1-467. (9) Burton, T. D.; Swindle, D. L.: Schwelkert, E. A. Radiochem Radioanal. Lett. 1973, 13, 191-198. (10) Ahlberg, M. S.; Leslle, A. C. D.; Winchester, J. W. Nucl. Instrum. Meth. 1978, 149, 451-455. (11) Borderie, B.; Barrandon, J. N.; Debrun, J. L. J . Radioanal. Chem. 1977, 3 7 , 297-306. (12) Dabney, S. A.; Swindle, D. L.; Beck, J. N.; Francis, G.; Schweikert, E. A. J . Radioanal. Chem. 1973, 16, 375-383. (13) Schweikert, E. A. J . Radioanal. Chem. 1981, 6 4 , 195-212. (14) Friedli, C.; Rousseau, M.; Lerch, P. J . Radioanal. Chem. 1981, 6 4 , 239-247. (15) Cumming, J. B. Brookhaven Natl. Lab., [ R e p ] BNL 1968, BNL 6470. (16) Northcliff, L. C.; Schilling, R. F. Nucl. Data Tables, Sect. A 1970, 7 , 233-437. (17) Fukai, R. U . S . A . E . C . Rep. 1958, AECU-3887. (18) Gladney, E. S.; Burns, C. E.; Perrin, D. R.; Roelandts, I.; Gills, Th. E. NBS Spec. Publ. 1984, No. 260-88, 12 and 75.
RECEIVED for review May 21,1984. Accepted July 20, 1984.
Bonded-Phase Extraction Column Isolation of Organic Compounds in Groundwater at a Hazardous Waste Site C. E. Rostad,* W. E. Pereira, and S. M. Ratcliff
U S . Geological Survey, Box 25 046, Mail Stop 407, Federal Center, Denver, Colorado 80225
A procedure for lsolatlon of hazardous organlc compounds from water for gas chromatography/mass spectrametry analysis Is presented and applled to creosote- and pentachlorophenol-contamlnated groundwater resultlng from wood-treatment processes. This simple procedure Involved passlng a 50-100-mL sample through a bonded-phase extraction column, eluting the trapped organlc compounds from the column with 2-4 mL of solvenf, and evaporating the sample to 100 pL wHh a stream of dry nltrogen, after which the sample was ready for gas chromatography/mass spectrometry analysis, Representatlve compounds lndlcaitlve of creosote contamlnatlon were used for recovery and precision studies from the cyclohexyl-bonded phase. Recovery of these compounds from n -0ctyl-, n -0ctadecyl-, cyclohexyl-, and phenyl-bonded phases was compared. The bonded phase that exhibited the be& recovery and least bias toward acldlc or basic cmpounds was the n-octadecyl phase. Detailed compound ldentlflcatlon Is given for compounds Isolated from creosote- and pentachlorophenol-contamlnated groundwater using the cyclohexyl-bonded phase.
Traditional methods for isolation of hazardous organic compounds from water for GC or GC/MS analysis are variations of the acid/base/neutral liquid-liquid extraction (1-4). After pH adjustment with aqueous H2S04or KOH, the water sample is extracted with an organic solvent in a separatory funnel. The pH is readjusted, and the water sample is reextracted. The organic extracts are dried by addition of anhydrous Na2S04,concentrated in a Kuderna-Danish apparatus, evaporated with dry nitrogen to the find volume, and injected into the GC/MS for analysis. This procedure involves large volumes of expensive solvents and extensive labor, time,
and glassware. In addition, each step in the sample preparation may introduce contamination or increase sample loss (5). The acid/base/neutral extraction method separates the organic compounds by functionality so that they can be analyzed on different GC columns. New versatile Durabond capillary columns make this separation unnecessary, so extracts are now combined for analysis. While significant advances have been made in analytical instrumentation and data management, sample preparation for organic analysis has remained virtually unchanged (6). An alternative sample preparation method was investigated an application of bonded-phase extraction columns. Previously, a different bonded phase had been used for each different compound class (7-9). In this alternative method, one bonded phase is used for isolating a variety of compounds rapidly, with no lengthy treatment of sample. This method involves passing the filtered groundwater sample through a small column containing a solid bonded-phase sorbent that sorbs the organic compounds. Then the column is eluted with a small quantity of solvent, and the sample is ready for GC/MS analysis. This method is much simpler than acid/ base/neutral extraction. Very little glassware is needed. It does not use much solvent. It does not take much time. Fewer steps mean less sample loss and fewer artifacts introduced. If the sample preparation method is effective in the laboratory, it can be applied onsite. Groundwater samples for organic analysis are usually pumped into 1-L glass bottles and shipped to a laboratory for acid/base/neutral extraction. Transfer of the groundwater sample from an anaerobic aquifer to an aerobic environment may initiate oxidation or biodegradation of the organic compounds, which continues during transport until the sample is extracted. Instead, the groundwater sample could be passed through the column as it is pumped from the aquifer at the sampling site. If organic compounds are isolated from groundwater immediately, much of the possible sample
This article not subject to U S . Copyrlght. Published 1964 by the American Chemical Society
ANALYTICAL CHEMISTRY, VOL. 56, NO. 14, DECEMBER 1984
alteration between the time of sampling and analysis would be eliminated. The light-weight column could be sealed and shipped t o the laboratory for elution and GC/MS analysis. T o test the feasibility of this onsite collection and preservation method, it was first studied in the laboratory. The application for this new method was the isolation of creosote compounds, resulting from wood-treatment processes, from contaminated groundwater collected near a hazardous waste site. Creosote contains a wide variety of organic compounds: phenols, polycyclic aromatic hydrocarbons, nitrogen, oxygen, and sulfur heterocycles (10,11). Many of these organic compounds had entered the aquifer. The bonded-phase extraction column would have to effectively isolate all organic compounds from the groundwater regardless of polarity, functionality, or water solubility. A group of representative compounds was chosen for recovery study, including 7 phenols, 10 polycyclic aromatic hydrocarbons, 2 sulfur heterocycles, 1oxygen heterocycle, and 6 nitrogen heterocycles. Compounds of increasing molecular weight and hydrophobic or hydrophilic character were included, t o pinpoint any recovery bias from increasing water solubility or molecular size. The compounds were spiked into natural groundwater collected from an uncontaminated area of the aquifer under study to include matrix effects (5). Recovery of these compounds from groundwater was studied using the cyclohexyl-bonded-phase extraction column. Recovery of these compounds from four different bonded phases was also studied. The method was applied to a contaminated groundwater sample collected near the hazardous waste site where groundwater contains creosote and pentachlorophenol.
EXPERIMENTAL SECTION Apparatus. Equipment for the extraction procedure consists of three main parts: a sample reservoir, the bonded-phase extraction column (Analytichem International), and a vacuum manifold. The cylindrical sample reservoir is made of polypropylene and is available in 75- and 150-mL capacities. The reservoir has a wide opening at the top for introduction of the sample and a narrow opening at the bottom that fits into the bonded-phase extraction column. An adapter forms a water-tight seal between the sample reservoir and the extraction coiumn below. The smaller 3-mL cylindrical polypropylene extraction column is one-third full with 500 mg of the bonded phase. A variety of functional bonded phases is available. Polyethylene frits are located above and below the bonded phase to hold minute particles in place and to keep the chromatographiccolumn intact. The extraction column fits directly into the vacuum manifold below. A beaker is placed in the vacuum manifold to collect the water as it elutes from the extraction column when vacuum is applied. A vacuum gauge on the manifold ensures that consistent, reproducible vacuum is applied to each water sample. Standards. Analytical standards for the quantitation compaunds were acquired from commercial sources (Aldrich Chemical Co., Merck and Co., ChemService,Polyscience, Ultra Scientific, and Fluka) and the U.S. Environmental Protection Agency. All organic solvents were high purity, distilled in glass (Burdick & Jackson). Freshly distilled water was exposed to UV radiation for 30 min in ORGANICpure (SYBRON/Barnstead) prior to use. Procedural blanks were verified to be clean. Various quantities of a standard mixture, containing 100 ng/pL of each compound, were used to spike the samples to obtain various concentrations in the natural groundwater for recovery studies. Samples were spiked with 100 ng/pL of the internal standard, phenanthrene-d,,, immediately prior to GC/MS analysis. A reverse-search library was generated, containing mass spectra and relative retention times of the internal standard and the compounds to be quantified. The GC/MS standards, solutions of the standard mixture at 50, 100, and 150 ng/pL, were analyzed to determine response factors for each compound relative to the internal standard, phenanthrene-d,@ A computer quantitation routine searched for each compound within an elution time window. If the library spectra matched a peak in the time window, the area of a preselected ion was quantified. This area was converted to a quantity, based on
2857
Table I. Precision Data of Five Replicates on Percent Recovery from Cyclohexyl-Bonded Phase, 200 mL a t 100 pg/L of Each Compound mean, %
compound
std dev
Phenols phenol 2-methylphenol 2,4-dimethylphenol 3,5-dimethylphenol 2,3,5-trimethylphenol 1-naphthol 2-naphthol pentachlorophenol
26.1 79.8 104.0 104.7 100.5 107.9 98.0 86.7
4.4 11.1
15.5 14.4 9.6 19.6 5.2 25.6
Polycyclic Aromatic Hydrocarbons indane naphthalene 2-methylnaphthalene 1-methylnaphthalene biphenyl acenaphthene fluorene phenanthrene anthracene
51.3 71.5 68.8 63.5 70.1 79.7 69.9 72.3 68.6
7.3 5.8 5.4 2.3 6.5 3.2 12.1
13.9 15.8
Sulfur Heterocycles benzothiophene dibenzothiophene
74.5 71.8
5.4 12.7
Oxygen Heterocycles dibenzofuran
72.2
8.3
Nitrogen Heterocycles 2,4-dimethylpyridine quinoline 2-methylquinoline 2-quinolinone acridine carbazole acridinone
0.0
69.7 11.8 85.6 20.5
11.3 4.4
16.7 13.6
81.0
12.7
111.3
32.2
the area of the internal standard base peak, by using the response factors determined previously. Throughout the study, at least one of the GC/MS standards was analyzed daily, and the new response factors were added to the response-factor lists. Procedure. Real samples were first filtered through prebaked glass-fiber filters (binder-free, Type A-E, Gelman Sciences) to remove suspended sediment. Native groundwater used in the recovery studies, however, was not filtered. The bonded-phase extraction column was cleaned by passing through 5 mL of methylene chloride, 5 mL of methanol, and then 5 mL of distilled, organic-free water. The column was not allowed to go dry before the water sample was added to the reservoir. The water sample, 50-100 mL, was slowly passed through the column using a 5mmHg vacuum. After the sample had passed through, the vacuum was left on for 5 min to dry the column. To remove the remaining water, the column was placed in a centrifuge tube and centrifuged a t 1000 rpm. A new centrifuge tube was used for elution. The column was eluted with of 1 of mL acetonitrile and two 2-mL portions of methylene chloride by adding the solvent t o the column, centrifuging to pass the solvent through, and collecting the eluate in the centrifuge tube. Residual water was eliminated by passing the eluate through a microcolumn of anhydrous Na2S04. The eluate was slowly evaporated to 100 p L under a stream of dry nitrogen, after the internal standard was added. Each prepared sample was analyzed within 48 h. Instrumentation. Analyses were performed on a Finnigan OWA 1020 computerized capillary gas chromatography/quadrupole mass spectrometry system (GC/MS). The GC was equipped with a fused silica capillary column 30 m long by 0.26 mm i.d. with 0.25-pm bonded film of DB-5 (J & W Scientific). The linear velocity of helium through the column was 26 cm/s. Splitless injections of 1pL were made at 280 "C. The GC oven was held at 50 "C for 4 min and increased at 6 "C/min to a
2858
ANALYTICAL CHEMISTRY, VOL. 56, NO. 14, DECEMBER 1984
Table 11. Percent Recovery from Cyclohexyl-Bonded Phase, 100 mL at 20 p g / L , 50 mL at 50, 100, and 200 pg/L
Table 111. Recovery from Four Bonded Phases at Approximately 100 pg/L
% recovery at, pg/L
compound
20
50
100
200
compound
n-octyl n-octadecyl
0
45 71
69 74
80 90 35
19 95 98 98 96 104
103 67
8 59 70 73 77
88 95 81
22
79 98 96 95 101 102 84
phenol 2-methylphenol 2,4-dimethylphenol 3,5-dimethylphenol 2,3,5-trimethylphenol 1-naphthol 2-naphthol pentachlorophenol
52 76 74
67 74
81 76 81 74
64 102 99 87 92 90 95 106 110
49
63 69 62
67 88 78 76
72 76
64
83 86 89
42 44 31
75
indane naphthalene 2-methylnaphthalene 1-methylnaphthalene biphenyl acenaphthene fluorene phenanthrene anthracene
82 76
108 99
67 87
92 44
benzothiophene dibenzothiophene
75
97
77
57
dibenzofuran
0 0
0 0
3
10 101 0
76
6 82
109
197
150
15 47
106 102
88 110 110
74
107
60
103
124
108
79
116 98 96
143 102 119
49
58
55
78 75
79
74 69
43 144
97
72
75 89
73 73 74
84 68
67 65
71
54
64
64 69 80
133 135
75 87 78 69 75
64
90 68
65 52
66 66
75 68
82 71
77 65
69
68
72
0 61
91
70
72
Nitrogen Heterocycles
Nitrogen Heterocycles 2,4-dimethylpyridine quinoline 2-methylquinoline 2-quinolinone acridine carbazole acridinone
27
Oxygen Heterocycles
Oxygen Heterocycles dibenzofuran
14 52
Sulfur Heterocycles
Sulfur Heterocycles benzathiophene dibenzothiophene
1.8 10 46
103 Polycyclic Aromatic Hydrocarbons
Polycyclic Aromatic Hydrocarbons indane naphthalene 2-methylnaphthalene 1-methylnaphthalene biphenyl acenaphthene fluorene phenanthrene anthracene
phenyl
Phenols
Phenols phenol 2-methylphenol 2,4-dimethylphenol 3,5-dimethylphenol 2,3,5-trimethylphenol 1-naphthol 2-naphthol pentachlorophenol
cyclohexyl
0
0
78
72 0
4
89 90 94 110
79 20 60 105
maximum of 300 "C. The vent valve was automatically opened at 45 s, and the filament and multiplier were automatically turned on at 240 s. The electron-impact MS was repetitively scanned from 40 to 450 amu in 1.0 s with 70-eV ionizing voltage and 250-wA ionization current.
RESULTS Cyclohexyl Recovery at 100 pg/L. Natural groundwater was spiked with 100 pg/L of each compound, passed through the cyclohexyl-bonded-phase extraction column, and analyzed by GC/MS. The precision data from five 200-mL samples as percent recovery are shown in Table I. Except for phenol, recovery of phenolic compounds was 80%-105%. Recovery of neutral compounds (polycyclic aromatic hydrocarbons, sulfur and oxygen heterocycles, and carbazole) was 51 %-111%. Recovery of the nitrogen heterocycles varied widely. Recovery at Different Concentrations. Solutions of 20, 50, 100, and 200 pg/L of each compound were prepared by using the natural groundwater. Recoveries of these compounds from 50 mL (100 mL for 20 pg/L) of groundwater from the cyclohexyl-bonded phase are shown in Table 11. Although the concentration of 100 pg/L was the same as in Table I, the sample size, and therefore the loading on the column, was different. The recovery was essentially the same. Pentachlorophenol recovery decreased significantly a t the lowest concentration, 20 pg/L. Recovery of neutral compounds was consistent with earlier data, although recovery of fluorene, phenanthrene, anthracene, and dibenzothiophene was less at a higher concentration, 200 pg/L. Recovery of 2-quinolinone
2,4-dimethylpyridine quinoline 2-methylquinoline 2-quinolinone acridine carbazole acridinone
2.7
0
0
65 36
87
11
75 55 80 128
58 9.1 73 7.9
45 67
96
40
71
113
8.2 118 1.5 83 170
and acridinone was high a t all concentrations. Recovery of other nitrogen heterocyclic compounds was low, except for quinoline a t higher concentrations. Recovery from Different Bonded Phases. Identically spiked groundwater samples, each containing approximately 100 pg/L of each compound, were passed through four extraction columns, each containing a different bonded phase. The n-octyl-, n-octadecyl-, cyclohexyl-, and phenyl-bonded phases recovered the assortment of compounds differently (Table 111). Recovery of neutral compounds which are hydrophobic was similar from each phase. Recovery of 2quinolinone, acridinone, and phenolic compounds was limited on the n-octyl phase. The other three bonded phases had similar recoveries. Recovery of nitrogen heterocycles was better from the n-octyl- and n-octadecyl-bonded phases, although no phase showed excellent recovery for these basic compounds.
DISCUSSION The cyclohexyl-bonded phase was very effective for recovering phenolic and neutral compounds spiked into natural groundwater. For most compounds, the recovery did not decrease even at lower concentrations. As low as 20 pg/L can be effectively recovered from a typical 50-mL sample. Recoveries varied for basic nitrogen heterocycles (quinoline, 2-methylquinoline, and acridine). 2,4-Dimethylpyridine was not recovered from the cyclohexyl-bonded phase. If this, compound was present in a sample, it would not be detected by using this method. Only 24% of the phenol was recovered from the cyclohexyl-bonded phase. Therefore, phenol may
ANALYTICAL CHEMISTRY, VOL. 56, NO. 14, DECEMBER 1984
2859
Table IV. Organic Compounds Identified in Groundwater Collected Near the Hazardous Waste Site Near Pensacola, FL peak no. 1 2
3 4 5 6 7 8 9 10 11
12 13 14 15 16 17 18 19 20 21
22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42
compound phenol benzonitrile benzofuran indane 1H-indene phenol, 2-methylethanone, 1-phenylphenol, 3-methylphenol, 2,g-dimethylCz-phenol Cz-phenol C,-phenol C,-phenol Cz-phenol phenol, 2,4-dimethylphenol, 3,5-dimethylphenol, 2,3-dimethylnaphthalene phenol, 3,5-dimethyla-terpineol benzo[b]thiophene phenol, 2,4,6-trimethylphenol, 3-(l-methylethyl)C3-phenol C3-phenol quinoline C3-phenol isoquinoline C3-phenol phenol, 2,3,5-trimethyl1H-inden-1-one, 2,3-dihydronaphthalene, 2-methylC3-phenol quinoline, 2-methylbenzo[blthiophene, 3-methylnaphthalene, 1-methylbenzaldehyde, 2,5-dimethylCl-quinoline benzaldehyde, 3,4-dimethylC1-quinoline 1.1’-bbhenvl naphtialenk, 2,6-dimethvl-
retention index sample std 972.7 977.6 991.3 1040.1 1041.9 1050.3 1064.7 1073.1 1105.0
977.9 995.8 1036.1 1045.3 1055.2 1077.3 1107.6
1111.2
1118.6 1126.7 1131.1 1143.5 1149.1 1170.2 1178.3 1188.8
1192.6 1194.4 1195.7 1204.6 1228.1 1234.0 1238.6 1242.5 1260.1 1265.4 1268.0 1272.6 1285.0 1298.7 1303.5 1313.3 1314.7 1316.8 1319.6 13.22.4 1342.0 1358.0 1383.9 1410.5
1
1150.0 1171.1 1180.8 1186.0 1193.6 1193.9 1203.9
1238.1 1261.4 1275.3 1298.4 1311.1 1316.0 1316.0
1384.4 1411.1
or may no be detected in the analysis. However, the other phenolic compounds exhibited excellent recovery. Adding NaCl to the samples prior to the procedure increased the phenol recovery to some extent, but recovery of the neutral compounds decreased substantially. The best pH for isolation of the suite of compounds based on pK, values was 5-7, which is the normal range of pH for groundwater. Isolation of organic compounds using the cyclohexyl-bonded-phase column provided an easy, rapid, and inexpensive sample preparation method that would be very useful in monitoring groundwater contamination. Each periodic sampling of the monitoring wells could involve 50-100 groundwater samples for immediate organic analysis. This method would streamline the sample preparation to an appreciable extent. Originally, each bonded phase was specifically used to isolate a particular chemical functional group. If one bonded phase could isolate all organic compounds, that would be ideal. Of the various bonded phases studied, the n-octadecyl had the most uniform recovery of the different compounds. Limited recovery of phenol and 2,4-dimethylpyridine occurred with each bonded phase. Becasue this limited recovery of phenol and 2,4-dimethylpyridine was independent of the acidity or basicity of the compounds, it may have been due to their volatility or solubility. However, indane is as volatile as phenol, and its recovery was much better than phenol recovery. The low capacity of the column for the very water soluble, very polar compounds may cause the limited re-
peak no. 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84
compound naphthalene, 1,6-dimethylC,-naphthalene naphthalene, 2,3-dimethyllH-indole-2-carbonitrile,3-methyl1H-indole, 2,3-dihydro-4-methylacenaphthene 1-naphthalenecarbonitrile I-naphthol [l,l’-biphenyl]-2-01 2-naphthol dibenzofuran 2-naphthalenecarbonitrile phenol, 2,3,4,64etrachloro1-indolinecarboxaldehyde 9H-fluorene Cl-naphthalenecarbonitrile
C1-acenaphthene C1-acenaphthene C1-acenaphthene C1-dibenzofuran C1-dibenzofuran C1-naphthalenecarbonitrile [ 1,l’-biphenyl]-3-01 3-quinolinol 2( 1H)-quinolinone 9H-fluoren-9-one dibenzothiophene pentachlorophenol phenanthrene-dlo (internal standard) phenanthrene acridine C1-2(1H)-quinolinone phenanthridine 9H-carbazole dibenzo[b,e][1,4]dioxin phenanthrene, 3-methylCl-9H-carbazole 4H-~yclopenta[d,e,flphenanthrene 9,lO-phenanthrenedione fluoranthene Dvrene 6hOHbacridinone
retention index sample std 1425.4 1429.1 1446.3 1463.4 1479.1 1494.0 1503.2 1514.3 1521.4 1522.2 1525.4 1529.4 1562.7 1584.9 1594.4 1600.0 1606.7 1612.5 1620.0 1631.7 1645.0 1653.3 1708.8 1718.4 1736.0 1751.8 1767.5 1771.9 1793.0 1797.4 1805.6 1826.9 1840.7 1851.9 1878.7 1910.8 1928.4 1936.3 1989.2 2084.7 2139.4 2362.1
1425.9 1446.7 1494.1 1500.4 1516.3 1525.4 1523.6
1593.1
1752.5 1766.1 1771.7 1793.6 1818.8 1839.8 1849.1
2083.7 2140.2
coveries. This effect can be minimized by using no larger than a 50-mL sample on the 500-mg column. Application Using an Actual Groundwater Sample. This method was successfully applied to determine the nature of creosote contamination in an aquifer. Only 25 mL of filtered groundwater was used to examine groundwater quality in detail. Actual recovery by the cyclohexyl-bonded-phase extraction column from a contaminated groundwater sample is shown in the reconstructed ion chromatogram in Figure 1. Compounds identified by GC/MS are shown in Table IV. Numbers in Figure 1 correspond to the compounds listed in Table IV. Kovats retention indexes (12) are given for each compound, with corresponding indexes from available authentic standards analyzed previously on the GC/MS. Basic compounds such as quinoline (peak no. 26),2-methylquinoline (peak no. 34), and acridine (peak no. 73) were recovered along with phenol (peak no. 1). Of the wide range of organic compounds in creosote, many diffused into the groundwater. This method isolated a large variety of compounds in one step.
CONCLUSIONS The bonded-phase extraction columns are a n alternative to the acid/base/neutral liquid-liquid extraction for isolation of organic compounds from water for GC or GC/MS analysis. The bonded-phase method efficiently recovers a variety of organic compounds from different functional groups in one step. In addition to involving less labor, time, glassware, and
2860
Anal. Chem. 1984, 56,2860-2862
'i
1I
ration methods such as these complement the advanced analytical instrumentation already available today.
LITERATURE CITED
Y 16
Bw IOW
Bw
IWO
12W
13M
1640
2oW
11w 2320
1Bw 2840
ISW 9W
ZWO SCAN 3320TlME
Figure 1. Reconstructed ion chromatogram (RIC) of a bonded-phase extract of cresote- and pentachlorophenol-contaminatedgroundwater.
solvent, the method minimizes sample exposure of the technician to possibly hazardous samples. This aspect is important, in view of the increasing demand for analysis of hazardous-waste-related samples. Using this method in the field would avoid the shipment, and possible breakage in transit, of potentially hazardous water samples. New sample prepa-
(1) Keith, L. H. "Identification and Analysis of Organic Pollutants in Water"; Ann Arbor Science: Ann Arbor, MI, 1976. (2) "Environmental Protection Agency Guidelines Establishing Test Procedures for the Analysis of Pollutants, Proposed Regulations"; U.S. Envlronmental Protection Agency: Washington, DC, 1979; FR 44, No. 233, pp 69540-69552. (3) "Environmental Protectlon Agency Guidelines Establishing Test Procedures for the Analysis of Pollutants, Proposed Regulations"; U S . Environmental Protection Agency: Washington, DC, 1979; FR 44, No. 233, pp 69514-69517. (4) Wershaw, R. L.; Flshman, M. J.; Grabbe, R. R.; Lowe, L. E. "US. Geological Survey Techniques of Water-Resources Investigations"; U.S. Geological Survey: Denver, CO, Vol. 5, Chapter A3, Open-File Report 82-1004. (5) ACS Committee on Environmental ImDrovement Anal. Chem. 1983. 55, 2210-2219. (6) Yago, L. S. Am. Lab. (Falrfleld, Conn.) 1984, 16, 4-6. (7) "Baker-10 SPE Applications Guide"; J. T. Baker Chemical Co.: Phiilipsburg, NJ, 1984; Vol. I and 11. (8) Dimson, P. LC, Llq. Chromatogr. HPLC Mag. 1983, 1. 236, 237. (9) Yee, G. C.; Gmur, D. J.; Kennedy, M. S. Clln. Chem. (Winston-Salem, N. C . ) 1082, 28, 2269-2271. 10) Lang, K. F; Eigen I . Fortschr. Chem. Forsch. 1967, 8 , 91-170. 11) Pereira. W. P. et ai. Envlron. Toxlcol. Chem. 1983, 2 , 283-294. 12) Kovats, E. Helv. Chim. Acta 1958, 4 1 , 1915.
RECEIVED for review May 25,1984. Accepted August 29,1984. The use of brand names in this report is for identification purposes only and does not constitute endorsement by the US. Geological Survey.
Synthesis and Chelation Properties of Hydrazones Derived from Isoquinoline-1-carboxaldehyde, 2-QuinoxalinecarboxaIdehyde, 4- Isoquinolylhydrazine, and 2-Quinoxalylhydrazine Francis H. Case
Department of Chemistry, Temple University, Philadelphia, Pennsylvania 19122
A. A. %hilt* and Ninus Simonzadeh Department of Chemistry, Northern Illinois University, DeKalb, Illinois 60115
The preparation and properties are described of 16 new qulnoxaiyl- and lsoqulndyihydrazones. Several of these afford very high sensltivltles for spectrophotometric determinations of transition-metal ions.
In continuation of our work on the synthesis of hydrazones capable of chelating transition-metal ions (l),we have synthesized three additional types and investigated them with regard to chelation of iron(II), cobalt(II), nickel(II), and copper(I1) ions. The three types differ from previously studied hydrazones in that they are related to either 2-hydrazinoquinoxaline, quinoxaline-2-carboxaldehyde,or 4-hydrazinoisoquinoline. We have found that several of these new hydrazones provide very high sensitivities in metal ion detection and measurement. They compare very favorably in this regard with previously described hydrazones for which practical analytical applications have been reported (2-7).
EXPERIMENTAL SECTION Preparation of the Hydrazones. A mixture of 0.004 mole each of a carbonyl compound and hydrazine in 25 mL of absolute ethanol containing 1drop of glacial acetic acid was heated at reflux
for 2 h. The solvent was then evaporated and the hydrazone crystallized from the solvent specified in Table I. The preparation of the intermediates required for these syntheses was according to methods previously described, summarized in the following sentences. 2-Hydroxyquinoxaline (8) was converted to the 2-chloro derivative (9),which treated with hydrazine (10) yielded the desired 2-hydrazinoquinoxaline. 4Hydroxyquinazoline (8) was converted to the chloro derivative (11)from which 4-hydrazinoquinazoline (12) was obtained. 2Methylquinoxaline (13)was oxidized by selenium oxide (14) to obtain quinoxaline-2-carboxaldehyde.Isoquinoline-l-carboxaldehyde was prepared by selenium oxide oxidation of 1methylisoquinoline ( 1 5 ) . 4-Aminoisoquinoline was prepared by amination of 4-bromoisoquinoline (16) which was diazotized followed by reduction with stannous chloride (17) to obtain the 4-hydrazinoisoquinoline. Chelation Studies. The procedures used to determine the pH ranges over which color formation occurred, wavelengths and molar absorptivities of maximum absorbance, conformance to Beer's law, and ligand/metal ion ratios have been described previously (18-20).
RESULTS AND DISCUSSION The new compounds are identified in Table I. Except for XIV, XV, and XVI, all formed colored complexes with man-
0003-2700/S4/0356-2860$01.50/00 1984 American Chemical Society
