Environ. Sci. Technol. 1994, 28, 850-858
Monitoring Aromatic Surfactants and Their Biodegradation Intermediates in Raw and Treated Sewages by Solid-Phase Extraction and Liquid Chromatography Antonio Di Corcla' and Roberto Samperi
Dipartimento di Chimica, Universith La Sapienza di Roma, Piazza Aldo Moro 5, 00185 Roma, Italy Antonio Marcominl
Dipartimento di Scienze Ambientali, Universith di Venezia, Calle Larga S. Marta 2137, 1-30123Venezla, Italy On the basis of solid-phase extraction, a simple procedure for determining simultaneously two aromatic surfactant classes, i.e., linear alkylbenzene sulfonates (LAS) and nonylphenol polyethoxylates (NPEO), as well as their biodegradation intermediates in raw and treated sewages is presented. This procedure involved passing 10 and 100 mL of an influent and effluent water sample, respectively, through a 1-g graphitized carbon black (GCB) extraction cartridge. By exploitingthe presence of positivelycharged active centers on the GCB surface, we succeeded in fractionating the complex mixture of the analytes considered by differential elution. The first fraction contained NPEO and nonylphenol (NP). The second fraction contained the carboxylated biotransformation products of NPEO, i.e., nonylphenoxy carboxylic acids (NPEC). Finally, the last fraction contained LAS and their metabolites, Le., carboxylic sulfophenyl acids (SPC). By suitably adjusting the chromatographic conditions, any group of analytes was subfractionated and quantified by liquid chromatography with fluorometric detection. Recoveries of all compounds of interest ranged between 89 % and 99%. This procedure was empolyed for 1 year to assess monthly the concentrations of the analytes considered in raw and treated sewages of a mechanicalbiological treatment plant.
Introduction The two aromatic surfactants linear alkylbenzene sulfonate (LAS) and nonylphenol polyethoxylate (NPEO) (Figure 11,have been extensivelystudied in the last decade, and their biodegradation behavior was characterized in a wide variety of laboratory (1-6)and field (7-17) conditions. The anionic LAS was shown to biodegrade quickly under aerobicconditions. LAS biodegradation intermediates are mono- and dicarboxylic sulfophenyl acids (SPC) that are formed by w-oxidation of the alkyl chain terminal carbon followed by successive @-oxidation(2). Under aerobic conditions, hydrolytic shortening of the polyethoxy chain of NPEO is generally favored, leading to the formation of lower oligomers, such as those having two (NPBEO) and one (NPlEO) ethoxy units ( 4 ) , and ultimately to the completely de-ethoxylated product, i.e., nonylphenol (NP) (18). Moreover, under an aerobic situation, the biodegradation experiments (6) and monitoring of treated sewages (19) showed that NPBEO and NPlEO can be subsequently oxidized to nonylphenoxy carboxylic acids
* To whom correspondence should be addressed. 850
Environ. Sci. Technol., Vol. 28, No. 5, 1994
Llnear Alkylbenrene Sulphonates (US) Nonylphenol Polyethoxylates (NPEO)
@?so; example of 4-C,, I A S
Sulphophenyl Carboxylates(SPC)
"n = 1,ZO Nonylphenoxy Carboxylates (NPEC)
I _
so3 example of SP3C,
NPlEC,
n=O
NPZEC,
n=l
Flgure 1. Structures and acronyms of linear alkylbenzene sulfonates (LAS), sulfophenyl carboxylates (SPC),nonylphenol polyethoxylates (NPEO), and nonylphenol polyethoxycarboxylates.
(NPBECandNPlEC, respectively). Only traces of NP3EC were detected by Ahel et al. (20) on analyzing effluents from various treatment plants in the area of Ziirich. A comprehensive final assessment of the environmental impact of the two surfactants and their metabolites mentioned above can be greatly encouraged by the development of selective, simple, and reliable analytical procedures for their simultaneous determination in environmental samples. Barber et al. (21) reported on the simultaneous determination of these compounds by employing the gas chromatography/mass spectrometry (GUMS) technique. The feasibility of separating LAS and NPEO by reversed-phase (RP) liquid chromatography (LC) with octyl- (C-8) or octadecyl-bonded silica (C-18) columns was shown (22, 23). In their pioneering work, Swisher et al. (24) showed that SPC mixtures could be successfully characterized by direct injection into a LC column. NPEC were analyzed by normal-phase HPLC after derivatization to methyl esters (20). Very recently, we assessed the feasibility of determining simultaneously LAS, NPEO, and their metabolites in water in a simple and rapid way (25). The analytes were extracted by a C-18 solid-phase extraction (SPE)cartridge, and the final extract was chromatographed by RP-LC with fluorometric detection. Graphitized carbon black (GCB), commercially referred to as Carbopackor Carbograph, is a well-known adsorbent extensively used for the SPE of a variety of analytes of environmental interest (26-30). As previously shown (30, 31),the extraction of complex mixtures from aqueous samples and their class fractionation by stepwise desorp0013-936X/94/09280850$04.50/0
0 1994 American Chemical Society
tion can be rapidly and easily achieved by the use of a single GCB cartridge. This work had two purposes. The first was to improve the analytical procedure cited above for determining simultaneously LAS, NPEO, and their biodegradation intermediates in aqueous samples. The second objective was to assess the concentrations of the analytes in raw and treated sewages as well as the distribution patterns of the biodegradation products of the two classes of surfactants. Experimental Section
Reagents and Chemicals. The two commercial surfactants Marlon A and Marlophen 810 were supplied by Chemische Werke Huls AG, Marl, Germany. Marlon A is a Clo-C13 LAS mixture. The exact percentage weight of each LAS homologue was 12.876, 41.876, 36.176, and 9.3%, respectively, for c10-c13 LAS (29). C9 LAS was synthesized by direct sulfonation of nonylbenzene at 70 OC (Fluka, AG, Bucks, Switzerland) (25). Marlophen 810 contains NPEO chain isomers and oligomers with an average of 11and a range of 1-18 ethoxy units. ImbentinN/7A, a mixture of 4-nonylphenol and mono- and diethoxylates, containing also small amounts of nonylphenol triethoxylate, was received from W. Kolb AG, Hedingen Switzerland. Pure Clz DATS was kindly supplied by L. Cavalli (Enichem Augusta Industriale). Some authentic biodegradation products of LAS and NPEO were synthesized and characterized according to procedures previously reported (25). They are as follows: sulfophenylacetic acid (SP2Cz);sulfophenyl-3-propionicacid (SP3C3); sulfophenyl-2-butyricacid (SP2C4);sulfophenyl-3-butyric acid (SP3C4); sulfophenyl-4-butyric acid (SP4C4); sulfophenyl-&valeric acid (SP5Cs); sulfophenyl-2-malonic acid (SP2DC3); sulfophenyl-3-glutaric acid (SP3DC6); nonylphenoxyacetic acid (NPlEC); nonylphenoxyethoxyacetic acid (NPPEC); and nonylphenoxydiethoxy acid (NPSEC). A mixture of ring and chain isomers of nonylphenol was supplied by Aldrich Chemical Co. (Milwaukee, WI). Stock solutions (1g/L) of the compounds and mixtures of the compounds reported above were prepared. Various working standard solutions were also prepared by appropriately mixing the various analytes. The compositions and the concentrations (reported in parentheses) of these solutions were as follows: solution 1,Marlophen 810 (100 mg/L) and NP (10 mg/L); solution 2, NPlEC and NP2EC (20 mg/L each); and solution 3, Marlon A (100 mg/L), CQ LAS (5 mg/L), and each individual synthesized SPC (20 mg/L). Trifluoroacetic acid (TFA), formic acid, tetraethylammonium chloride (TEACl), and tetramethylammonium hydroxide-5H20 (TMAOH) were from Aldrich. For LC, distilled water was further purified by the Elgastat UHQPS apparatus (Elga, Buchs, U.K.). Methanol of chromatographic grade, labeled as “Chromasolv”, was from Riedel de Haen, Selze, Germany. All other solvents were of reagent grade and were used as supplied. The eluant systems utilized for the stepwise desorption of the analytes from the GCB surface were as follows: eluant A, methylene chloride/methanol(7030,v/v); eluant B, 25 mmol/L of formic acid in methylene chloride/ methanol (90:10, v/v); eluant C, 10 mmol/L of TMAOH in methylene chloride/methanol(90:10,v/v). The eluant phases were prepared daily and stored at 4 OC when unused. GCB (120-400 mesh size) and the other materials used for preparing SPE cartridges were supplied by Alltech
Associates, Deerfield, IL. The extraction cartridge was prepared by packing 1 g of GCB in a polypropylene tube (6.7 x 1.3 cm i.d.) and placing polyethylene frits above and below the sorbent bed. To avoid crushing the GCB particles, which results in a decrease in the permeability of the cartridge, the upper frit was placed gently on the sorbent bed. The trap was fitted into a side-arm filtering flask, and liquids were forced to pass through the cartridge by vacuum from a water pump. Before processing water samples, the cartridge was washed sequentially with 7 mL of eluant C, 3 mL of methanol, and 30 mL of distilled water acidified with HC1 (PH 2). Sample Collection. Over 1year, influent and effluent waters were collected monthly in glass bottles as 24-h composite samples from one mechanical-biological sewage treatment plant in the area of Rome. Samples were preserved in 176 (v/v) formalin. If not assayed within 1-2 days, samples were stored at 4 “C. Sample Preparation. Before extraction, water samples were vigorously shaken to ensure adequate mixing and suspension of particulate material. Immediately after that, 10 and 100 mL of influent and effluent water samples respectively were taken, and the sewage effluent samples were acidified to pH = 3 with concentrated HC1. This operation served to increase the retention volumes of the dicarboxylated forms of SPC on the GCB cartridge. For recovery studies, known volumes of the composite working standard solutions of surfactants and their intermediates were added to water samples. After the samples were spiked, the analytes were allowed to equilibrate between water and the suspended material for a couple of hours. The analytes were extracted by passing the sample through the GCB cartridge at flow rates of about 20-30 mL/min with the aid of vacuum. A sample of 10-15 mL of distilled water, which was used to wash the reservoir containing the sample, was then passed through the trap. An additional 7 mL of water was applied directly to the top of the cartridge. Water remaining in the cartridge was partially removed by drawing room air through the cartridge for 1 min. Residual water was eliminated by slowly passing through the trap 2 mL of methanol. After air-drying the trap, a conical-bottom glass vial (-1.4 cm id.) was placed below the cartridge, and 7 mL of eluant A was percolated at 4-5 mL/min through the sorbent bed for desorbing NPEO and NP. The last drops of eluant A were collected by decreasing the pressure in the flask. This operation was repeated when collecting the other two fractions. After suitably regulating the pressure, the fraction containing the weakly acidic analytes, i.e., the carboxylated forms of NPEO, was eluted by 7 mL of eluant B and collected in a second vial. Finally, LAS and their related SPC intermediates were eluted from the cartridge with 7 mL of eluant C. Before solvent removal, the basic extract C containing LAS and SPC was neutralized by adding 120 pL of formic acid (1mol/L) in acetonitrile. This operation was done in order to avoid partial esterification of the carboxylic groups of the SPC by methanol in a basic solution. Extract B containing NPEC and extract C containing LAS and SPC were dried in a water bath at 30 OC under a nitrogen stream. Extract A containing NPEO and NP was concentrated to an approximate volume of 200 pL. Some evaporative losses of NP (nonylphenol) were observed by concentrating the extract at lower volumes. After being Environ. Scl. Technol., Vol. 28, No. 5, 1994
851
dried, the residue of extract B was reconstituted with 200 pL of a water/methanol mixture (35/65, v/v) containing a phosphate buffer (10 mmol/L, pH 6.9) and TEACl (10 mmol/L). A 50-pL sample of this solution was injected into the LC apparatus. A total of 200 pL of a water/ methanol mixture (50/50, v/v) acidified with TFA (0.2 %) was used for reconstituting the residue of extract C, and 20 pL of this solution was analyzed by LC. Finally, 50 r L of the final extract A was injected into the LC column after measuring exactly its volume. LC Analysis. Liquid chromatography was carried out with a Varian (Walnut Creek, CA) Model 9010 ternary pump chromatograph equipped with a Rheodyne Model 7125 injector having a 50-pL loop and with a fluorometric Model 650-10-s (Perkin-Elmer Corp., Norwalk, CT) detector. A 25 cm X 4.6 mm i.d. column filled with 5-pm particlesize, Csreverse-phase packing (Supelco) was used. Solvent A was water with 0.2% (v/v) TFA. Solvent B was phosphate buffer (1 mmol/L, pH 6.5) with TEACI, 10 mmol/L. Solvent C was methanol. For separating LAS and their related biodegradation product8 (SPC),the initial mobile phase composition was 90% solvent A and 10% solvent C. This was programmed linearly to 80%after 50 min. Whenanalyzing LAS ininfluentsoftreatmentplants, theanalytes werechromatographed isocraticallywith76% solvent C. NPEO and NP were eluted with 23% solvent B and 77% solvent C. Finally, the NPEO metabolites (NPEC) were fractionated by 65% solvent C and 35% solvent B. When the mobile phase used for subfractionating NPEC was replaced with that selected for chromatographing LAS and SPC,or viceversa,an equilibration time of more than 30 min was required to obtain reproducible chromatographic conditions. In order to save time, the three fractions were chromatographed in the following order: fraction C, followed by fraction A, and lastly, fraction B. In all cases, the flow rates of the mobile phases were 1.5 mL/min. The fluorometric detector was set a t an excitation wavelength of 225 nm (10-nm slit width) and an emission wavelength of 295 nm (15-nm slit width). Quantitation. Peak area measurements were carried out by the use of a Model 1020 P E Nelson integrator (Perkin-Elmer). The concentrations in unspiked and spiked samplesof those analytes for which standards were available were calculated by external calibration. The quantitation of the larger types of both SPC and NPEC, for which standards were not available, was carried out as described below. The responseofthefluorometricdetector was linearly related to injected amounts of every analyte up to 10 pg.
Results and Discussion Analyte Group Fractionation. The GCB material has on its surface pcaitively charged oxygen complexes able to bind anions via electrostatic forces. The surface concentration of these singular adsorption sites was reportedto be76nequiv/m2(32). Althoughfewinnumber, the presence of these active centers enables GCB to act as both an anion exchanger and a nonspecific adsorbent. This peculiarity is well-illustrated in Figure 2, where the separation of some selected analytes representative of each class of surfactants and related degradation produds is shown. In this experiment, the surfactants and their intermediates were adsorbed onto the GCB surface from 100 mL of a tap water sample. 832 Envhon. Scl. Tednol.. Vd. 28, No. 5. 1994
BO 50 % 40 R.cw*rl 30
20 10
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4
6
8
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Flgure 2. &oup wpratbn of LAS. NPEO, and their biointarmedlates by the GCB extraction cartrEge. The compositions of the Wee eluant systems are reported under the Experimental Sectlon.
Neutral compounds, such as NPEO, were eluted from the extraction cartridge by passing through it a neutral solvent mixture (eluant phase A). This mixture was also able to elute NP, which is a very weakly acidic compound. In a recent study (32),we observed that a complete haseneutral/acid fractionation could be achieved by a GCB column, provided the acidic compounds have a pK. lower than 7. In accordance with the behavior shown by conventional anion exchangers (33),complete desorption of weakly acidic compounds, such as NPEC, was achieved by moderately acidifying a suitable eluant organic solvent mixture, while the more acidic LAS and SPC still remained adsorbed onto the GCB surface. These latter compounds were completely removed from the adsorbent by adding to the solvent mixture a more effective displacing agent, such as TMAOH (32). By this procedure, we measured that the individual concentrations of each SPC and NPEC species in sewage influents were very close to the detection limit of this method. Moreover, the analytical LC column procedure was able to separate LAS from NPEO. Nevertheless, we maintained the same extraction and purification scheme as for the effluent water samples. Thus, NPEO and LAS were collected in two separate fractions and separately quantified by LC, while the intermediate fraction containing weakly acidic species was discharged. Again, this was done in order to decrease the possibility of interferences with the analysis of the two surfactant classes by unknown compounds. Chromatography. In our previous work ( B ) , a C r L C column was selected for separating a LAS mixture. This column offers the advantage over the commonly used Cta one in that all the positional isomers of each LAS homologue are eluted as a single peak. In this situation, the interpretation and the quantitation of the chromatograms are facilitated. Unfortunately, when chromatographing SPC, this favorable condition was not encountered. In fact, by both using the ion-pair (IP) and the ion-suppression (IS)LC techniques, we observed that the three synthesized isomers of the sulfophenylhutyric acid (SPCd were eluted as three distinct peaks. In both cases, these three compounds were eluted with retention times that increase as the attached benzene ring approachesthe carboxylic group. In terms of retention and peak sharpness, LAS and SPC can be positively chromatographedby both the IP and the IS techniques. As shown elsewhere (%), the elution order of SPC by the latter technique follows more strictly that of decreasing polarity of the eluates. This feature of the IS technique can be advan-
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Flgure 3. LC chromatograms of SPC derived from both LAS and DATS obtained by injecting extract C (see the Experimental Section) of (A) an aerobic bioassay sampies:biotransformation products of C, ,-LAS (upper), C12-LAS(middle),and a Cl0-Cl3-LAS mixture(lower); (6)a sewage effluent sample, and (C) an aerobic bioassay sample containing C12-DATS.
tageously exploited for tentatively assigning peaks of a complex chromatogram to those SPC for which authentic standards are unavailable. For this reason, we chose the IS technique for the subfractionation of SPC. In Figure 3A, the chromatograms for authentic SPC are shown, while a typical chromatogram obtained from analyzingan extract of a treated sewage sample containing SPC and residual LAS is presented in Figure 3B. The former chromatograms were obtained by injecting extracts relative to aqueous solutions where SPC were generated by an activated sludge inoculum. These laboratory experiments were conducted by following a procedure reported elsewhere (34). The identification and quantification of the LAS metabolites formed by the aerobic bioassays were carried out by GC/ MS according to a method developed by Trehy et al. (35). On this basis and considering the elution order of the synthesized positional isomers of SPC4 on the LC column, peaks for the other in vitro generated SPC were individuated on the LC chromatogram. As can be seen, the fractionation of the SPC-containing extract of the treated sewage produced a large number of peaks that only in part could be assigned to LAS intermediates. Dialkyltetralin sulfonates and dialkylindane sulfonate (DATS) are alicyclic analogs of LAS present in LAS formulations in the range from 0.4% to 14% (36). Field et al. (16) found that the concentration of the DATS intermediates in a treated sewage was comparable to that of LAS ones. To evaluate whether unidentified sulfocarboxy compounds leavingthe
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plant were DATS intermediates, pure C12-DATS was biodegraded, and its metabolites were characterized in the same way as the LAS intermediates. GC/MS analysis showed that DATS-derived SPC having Ce-Clo residual alkyl chain lengths were generated. A corresponding LC chromatogram is shown in Figure 3C. In this chromatogram, unfortunately, no definite peak identification could be made because of the lack of information on the HPLC behavior of DATS intermediates. A work is in progress to fully characterize SPC in treated sewages coming from both LAS and related impurities by ion spray HPLC mass spectrometry. At this stage, by comparing the chromatograms in Figure 3 panels B and C, it can be only stated 854
Envlron. Scl. Technol., Vol. 28, No. 5, 1994
that DATS-derived SPC represent a remarkable fraction of all of the SPC species leaving the plant. As to NPEC, we selected the IP-LC technique for chromatographing them. This choice was dictated by the fact that, when undissociated, NPEC are virtually nonfluorescent species. Together with a chromatogram of the synthesized NPlEC-NP3EC mixture, two selected chromatograms representative of two borderline situations encountered on analyzing NPEC in effluents are shown in Figure 4. Several considerations suggested that peaks appearing after that of NP3EC could be ascribed to the presence in the effluent of higher NPEC oligomers (NP>3EC). To obtain direct evidence of the unexpected
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Figure 6. Typical LC chromatogram of NPEO and NP obtained by injecting(A) a standard solution and (B) extract A (see the Experimental Section) of a treated sewage sample.
presence of NP>3EC in treated sewages, a NPECcontaining extract was analyzed by ion spray HPLC-MS. Briefly, the extract was injected into the HPLC column with water/acetonitrile (30/70, v/v) acidified with 0.02 % TFA (v/v) as the mobile phase. A suitable fraction of the effluent from the column was introduced to a Perkin Elmer Sciex API I mass spectrometer equipped with an atmospheric pressure articulated ion spray source. Qualitative analysis was performed by selective-ion monitoring (SIM) with rnlz values corresponding to protonated molecular ions ranging from 367.2 [NPE3C+Hl+ to 675.2 [NPElOC+Hl+. The mass chromatogram reported in Figure 5 clearly demonstrates that NPEC having more than two ethoxy units can also occur in treated sewages. Finally, Figure 6 shows a chromatogram obtained by injecting the standard solution containing both NPEO and NP. Under the chromatographic conditions used by us (221, all the various oligomers and isomers of NPEO were eluted as a single broadened peak. From this point onward, the acronym NPEO will indicate the total NPEO. In the same figure, a typical chromatogram obtained from analyzing an extract of a treated sewage sample containing the compounds mentioned above is also presented. Recovery Studies. Surfactants present in both influent and effluent water samples are distributed between the liquid phase and the particulate matter suspended in it. In our experience, up to 90% of the CWLAS present
in influent aqueous samples can be adsorbed by suspended solids. This situation led Swisher (1) to the conclusion that it is very difficult, if not impossible, to take a representative fraction of the sample contained in the collecting bottles. To circumvent this difficulty, some authors (37) proposed to separate the solid phase from the liquid one, extract surfactants from the particulate matter and add the extract to the liquid phase. In order to evaluate whether specific, time-consuming expedients had to be adopted for obtaining an accurate measurement of the surfactant concentrations in sewage samples, some experiments were conducted. One 24-h composite sample of an influent sewage and that of the corresponding final effluent were collected in calibrated glass bottles and assayed by followingthree different subsampling methods. The first method was the filtration of the sample and the separate analysis of the surfactants contained in the two phases. The second method, the simplest one, was to vigorously shake the bottle containing the sample for 1 min, and immediately after that, to take a fraction that was carried through the extraction procedure. The third method involved desorption of the analytes from suspended solids by the addition of a known volume of methanol (=50%, v/v) to the aqueous sample, 1-min shaking, and extraction of the sample after 1 h to allow adsorbed surfactants to migrate toward the partially organic liquid phase. As measured by us, 313 and 16mg/L were the respective amounts of particulate matter present in the influent and the effluent samples examined. Analyses were made in triplicate. By comparing the data reported in Table 1,it appears that no significant variation of the concentrations of LAS and NPEO was evident by varying the sampling method. The absence of any adverse effect obtained by following the second subsampling procedure was likely the result of particular care taken on drawing rapidly an aliquot of the aqueous sample, while the particulate matter was still uniformly dispersed. In fact, when sample withdrawal did not immediately follow the shaking, LASS were progressively lost, according to their alkyl chain length. The influence of the volume of an effluent sewage sample applied to the GCB extraction cartridge on the recovery and group separation of surfactants and their metabolites was assessed. For this purpose, a pooled (n = 5) treated sewage sample containing NPEO, NP, NPlEC, LAS, and SPC was acidified to pH = 3 and amended by adding stock solutions of sulfophenylmalonate (SP2DC3), sulfophenylglutarate (SP3DC& and sulfophenylpropionate (SP3Cd to produce individual concentration levels of 100
Table 1. Concentrations (pg/L) of LAS,NPEO, and N P Measured in Sewage Samples by Varying the Sample Preparation Method. method sewage phase
lb
2c
-
3d
raw solid
treated raw treated raw treated liquid total liquid solid total Ce LAS 239 13 252 0.8 0.8 238 0.7 257 0.8 Cio LAS 959 271 1230 3.3 0.1 3.4 1215 3.2 1240 3.2 Cii LAS 1139 907 2046 8.1 1.3 9.4 2021 9.7 2075 9.8 Ciz LAS 684 1676 2360 5.9 2.2 8.1 2321 8.3 2305 8.5 Ci3 LAS 138 1100 1238 1.9 1.8 3.7 1251 3.7 1268 3.8 NPEO 154 49 203 6.9 3.0 9.9 208 9.6 195 9.9 NP 1 11 12 0.3 0.7 1.0 13 1.0 11 1.1 Average values from triplicate measurements. Sample filtration followed by separate determination of the analytes in the two phases. Subsampling immediately after sample agitation. Analyte determination after sample dilution (l:l, v/v) with methanol.
*
Environ. Sci. Technol., Voi. 28, No. 5, 1994
855
Table 3. Precision of Method (n = 6) for Determination of LAS, NPEO, and Some Selected Related Biodegradation Intermediates
Table 2. Accuracy of Method for Determination of LAS, NPEO, SPC, and NPEC in Raw and Treated Sewages raw sewage
treated sewage wncn av % added recovery
raw aawage mncn CVa
*
&? CiLAS 113-302 CloLAS CnLAS CnLAS &LAS SP24 SP3Cs SPZC, SP3Cb SP4Cb SP5Cs SP2DCa SP3DCs NPEO NP
64C-1620 10962703 635-1462 174-481 ndc nd nd nd nd nd nd nd 64-115 2.7-7.5
__ nd
6w 1900 6100 5270 1360
96+7
96t5 95+4 94+4 92+7
200 20
96f4 89+7
NPlEf! ... .-- nd
NP2EC
