Agilent Analysis of Active Compounds using the New Highly Inert HP-5Msi Column
Contents
1. C min to 200 C 8 C min to 280 C 10 min MSD 280 C scan 50 500 amu 0 5 uL cool on column oven track 50 C 1 min 12 C min to 250 C 1 min 25 C min to 300 C 10 min MSD 280 C scan 50 500 amu or FID 320 C A column performance comparison of the new Pesticides HP 5MSi column and a standard 5ms column is shown in Figure 1 The 5ms column from another A series of pesticide samples were prepared to fur manufacturer shows severe peak tailing for the ther evaluate the performance of the HP 5MSi more active compounds The new HP 5MSi column column Figure 2 shows a total ion chromatogram exhibits much improved peak shapes for this chal TIC of a number of different pesticides at a level of lenging analysis and demonstrates the benefits a 0 1 ng on column more complete deactivation can have for the analy sis of a wide range of active compounds pA HP 5MSi 26 2 3 24 1 4 22 5 20 e 8 0 4 184 164 nM y H A 144 i T 1 T T 1 0 2 4 6 8 10 12 Minute Test Mix 1 Compound ng injected 1 Methane 2 Propionic acid 7 0 ru 3 Octane 24 pA 3 Competitive 5ms 4 Nitrobutane 4 9 26 2 5 4 Picoline 2 7 1 4 6 Trimethyl phosphate 127 7 1 2 Pentanediol 5 4 247 8 Propylbenzene 22 9 1 Heptanol 3 3 224 10 3 Octanone 3 0 8 11 Decane 2 2 204 5 3 10 6 7 11 184 16 T Jk w VENE 144 T T T T i T 0 2 4 6 8 10 12 Minute Figure 1 A performance comparison of t2. 20 00 22 00 Time Figure 4 Basic semivolatiles sample containing 1 ng of each component on an HP 5MSi column Conclusions Method 8270 Agilent Technologies publication 5968 3072EN The new HP 5MSi column permits the analysis of www agilent com chem low levels of pesticides and other active com pounds such as semivolatile phenols and amines because of its highly inert surface Peak tailing is minimized thereby allowing low levels of these polar compounds to be determined In addition the resulting calibration curves are linear with low 4 M Szelewski Fast USEPA 8270 Semivolatiles variation in response factors Analysis Using the 6890 5973 inert GC MSD with Performance Electronics Agilent Technologies publication 5989 1510EN www agilent com chem 3 F Feyerherm and H Prest Fast GC MS Method for Routine Drug Analysis Agilent Technologies publication 5868 4780E www agilent com chem References 1 P Wylie M Szelewski C K Meng and C Sandy Comprehensive Pesticide Screening by GC MSD using Deconvolution Reporting Soft ware Agilent Technologies publication For more information on our products and services 5989 1157EN www agilent com chem visit our Web site at www agilent com chem 2 M Szelewski W Wilson and P Perkins Improvements in the Agilent 6890 5973 GC MSD System for Use with USEPA For More Information A Critical Supplies Needed Description HP 5MSi column Column nut ALS n
3. Chlorophenol 11 Naphthalene IS 5 o Cresol 12 24 Dichlorophenol 6 p Cresol 13 4 Chlor 3 methylphenol 7 2 Nitrophenol 14 2 4 6 Trichlorophenol 800000 11 750000 8 700000 1 5 6 650000 4 10 12 600000 550000 500000 3 S 450000 4 S 400000 aX 2 350000 300000 250000 200000 9 150000 100000 50000 4 00 5 00 6 00 7 00 8 00 9 00 Time 15 16 17 18 19 20 2 4 5 Trichlorophenol 2 4 Dinitrophenol 4 Nitrophenol 2 3 4 6 Tetrachlorophenol 4 6 Dinitro 2 methylphenol Pentachlorophenol 20 17 10 00 11 00 12 00 13 00 14 00 Figure3 Acidic semivolatiles sample containing 1 ng of each component on an HP 5MSi column Amines Mixture 1 2 Picoline 8 1 Chloronaphthalene 15 Pentachloronitrobenzene 2 Acetophenone 9 Pentachlorobenzene 16 Pronamide 3 N Nitrodopiperidine 10 1 Naphthylamine 17 p Dimethylaminoazobenzene 4 o o Dimethylphenethylamine 11 2 Naphthylamine 18 7 12 Dimethylbenz a anthracene 5 Naphthalene IS 12 4 Aminobiphenyl 19 3 Methylcholanthrene 6 N Nitrosodi n butylamine 13 Phenacetin 7 1 2 4 5 Tetrachlorobenzene 14 Diphenylamine 5 12 b 850000 800000 4 750000 4 l 8 9 700000 650000 4 E 600000 4 2 550000 4 10 2 500000 4 11 14 450000 4000004 350000 4 300000 17 250000 4 6 15 200000 4 150000 4 Miu 13 100000 4 16 50000 ae L i A a e zd u 4 00 6 00 8 00 10 00 12 00 14 00 16 00 18 00
4. Analysis of Active Compounds Using the New Highly Inert HP 5MSi Column b A Application E o e o o e e e 0 o o o 0 0 e o e o e Environmental Analysis e e e Authors Eberhardt Kuhn and Mitch Hastings Agilent Technologies Inc 91 Blue Ravine Drive Folsom CA 95630 Alan Broske Agilent Technologies Inc 2850 Centerville Road Wilmington DE 19808 1610 USA Abstract Quantitating low levels of very active compounds can be facilitated with the use of a highly inert capillary column The use of the highly inert HP 5MSi column in conjunction with the Agilent 6890 5973 inert gas chromatograph mass spectrometer GC MS system allows the measure ment of pesticides and environmental contaminants at low levels while maintaining response linearity over a wide concentration range Introduction The analysis of active compounds by gas chro matography GC continues to be challenging in such areas as pesticide 1 environmental 2 and drug analysis 3 Adding to this problem is the need to reduce detection limits DLs to the low nanogram level To meet these demanding require ments almost every GC column manufacturer has developed a low bleed column Low column bleed reduces detector noise and increases signal to noise which improves DLs However lowering column bleed alone does not address the problem of peak tailing that results from interactions of polar compounds with active sites within the sample f
5. eedle support Syringe 5 uL Syringe needle Septum Septum nut Inlet insert 6 rings Graphite ferrule Preconditioned ferrules for 0 25 mm column MS interface nut Part number 190918 433i 5181 8830 G1513 61295 5182 0836 5182 0833 5183 4758 109245 80521 19245 20515 5080 8853 5062 3508 05988 20066 www agilent com chem Agilent shall not be liable for errors contained herein or for incidental or consequential damages in connection with the furnishing performance or use of this material Information descriptions and specifications in this publication are subject to change without notice Agilent Technologies Inc 2004 Printed in the USA October 1 2004 5989 1687EN Agilent Technologies
6. he new HP 5MSi column and a competitive 5ms column with Test Mix 1 Pesticide mixture 1 o BHC 8 y Chlordane 15 44 DDD 2 p BHC 9 Endosulfan 16 Endrin aldehyde 3 y BHC 10 o Chlordane 17 Endosulfan sulfate 4 8 BHC 11 Dieldrin 18 44 DDT 5 Heptachlor 12 44 DDE 19 Endrin ketone 6 Aldrin 13 Endrin 20 Methoxychlor 7 Heptachlor epoxide 14 Endosulfan Il 21 Decachlorobiphenyl IS 95000 85000 4 75000 4 65000 1 1 3 2 3 J 6 12 15 E 55000 10 jg 19 a 4 45000 5 89 ur 2 7 16 35000 2 25000 4 15000 L 34 AA 31 E E E 5 00 10 00 15 00 20 00 25 00 30 00 35 00 40 00 Figure 2 Pesticide sample containing 0 1 ng of each component on an HP 5MSi column Even at this concentration level in scan mode it is possible to determine compound identity with greater than 85 confidence after baseline subtrac tion by spectral matching alone Retention time locking RTL and matching retention times RTs to the pesticide database confirmed compound identification To further demonstrate the performance of the HP 5MSi it is important to have linear calibration curves over a broad range of concentrations A series of tests were performed on the HP 5MSi column using selected pesticides that are known to adsorb strongly to active sites within the column Standard samples were prepared containing terbo fos malathion endrin aldehyde and DDT at differ ent concentrations and used to prepare a calibratio
7. low path of the GC Active compounds will adsorb on active sites throughout the sample flow path including the injection port liner and seal in a split splitless inlet along with the capillary column and any metal detector parts Various deactivations were used to deactivate glass liners and capillary columns and different metal passivation tech niques have had similar effects on seals and mass spectrometer sources 4 Unfortunately treating these parts in such a manner does not completely remove all the unwanted active sites One of the major sources of active sites can be the capillary column Keeping in mind the large sur face area of a standard column and long residence time of an analyte in the column it is not surpris ing that peak tailing and response loss can occur even with the most highly deactivated columns Further gains in detection sensitivity could be realized if the number of column active sites was reduced by more complete deactivation procedures We report here the use of a new HP 5MSi MS Inert column that has low column bleed and is specially deactivated for the analysis of polar com pounds that show noticeable adsorption especially at low concentrations The column performance was evaluated using a specialized testing protocol and then subsequently tested with different active pesticides and environmental compounds E p Agilent Technologies Sample Preparation As a qualitative test for column inertnes
8. n curve for each compound Table 2 summarizes the deviation in Response Fac tors RFs as percent relative standard deviation RSD and correlation coefficient x for these compounds over the concentration range tested The HP 5MSi column shows superior performance when compared with the competitive 5ms column for linearity over the concentration range tested and deviation in response factors Table 2 Calibration Results of Pesticides on HP 5MSi and Another 5ms Column HP 5MSi RSD P RSD Terbofos 5 2 0 9999 8 9 Malathion 5 2 0 9998 23 8 Endrin aldehyde 3 7 0 9997 29 1 DDT 7 1 0 9998 3 7 Competitive 5ms Semivolatiles Itis very important that the capillary column be highly inert for the analysis of semi volatile phenols and amines especially at low levels Many of these semivolatile compounds typically show severe loss of response at trace levels Figures 3 and 4 show both acidic and basic compounds on the new HP 5MSi column Even at 1 ng on column peak shape is still very good and the strong response allows for accurate quantitation Calibration curves were linear from 100 to 2 5 ng with 10 15 relative standard deviation RSD for difficult active compounds like 2 4 dintrophenol and pentachlorophenol Acid Mixture 1 Methyl methanesulfonate 8 2 4 Dimethylphenol 2 Ethyl methanesulfonate 9 Benzoic acid 3 Phenol 10 2 4 Dichlorophenol 4 2
9. s an application specific test sample Test Mix 1 was prepared Individual components were obtained from Sigma Aldrich St Louis MO and diluted in dichlorobenzene Pesticide samples were obtained from AccuStan dard New Haven CT at 1000 ug mL in different solvents and diluted as needed Linearity studies were performed using a sample of terbofos malathion endrin aldehyde and DDT over the range 0 8 100 ng uL in methanol 0 4 50 ng injected A number of substituted phenols and semivolatile amine samples were obtained from AccuStandard New Haven CT at 2000 ug mL in different sol vents and diluted as needed Linearity studies were performed using a sample of 2 4 dinitrophenol pentachlorophenol and n nitrosodipropylamine over the range 5 200 ng uL in methanol Chromatographic Conditions All the HP 5MSi columns used in these tests have met the requirements for low column bleed and selectivity of the standard HP 5MS columns Chro matographic conditions are detailed in Table 1 Additional equipment used is summarized in Appendix A Test Mix 1 was then developed as a stringent but simple test for column activity The chromato graphic conditions were chosen such that the He 0 7 mL min RTL on active compounds had sufficient retention and res olution Peak tailing of the polar compound would be an indication of column activity Initial testing of the HP 5MSi column with pesti cides and environmental compounds wa
10. s per formed using a GC configured with an on column injector and an inert source MSD These conditions indicated how well the column performed when identifying these compounds at low levels Detailed linearity studies of selected pesticides and environmental compounds used a GC config ured with an on column injector and an FID This instrument configuration reduced the potential for compound interactions with metal surfaces and allowed us to more effectively evaluate the perfor mance of the column alone Lastly all pesticide samples were run using the standard chromatographic conditions used with the Retention Time Locking RTL pesticide data base 1 Pressure was adjusted to lock chlorpyrifos at 16 596 minutes Results Column Evaluation The column performance for active compounds was evaluated first using Test Mix 1 The presence of active sites was indicated by a loss in peak height area or evidence of peak tailing of the active pesticide acids or bases relative to an inactive compound like octane Semivolatile phenols and amines He 1 3 mL min chlorpyrifos 16 596 min Table 1 Chromatographic Conditions Application Test Mix 1 Pesticides Column HP 5MSi 30 m x 0 25 mm x 0 25 um Carrier gas H2 1 mL min Injector 250 C 50 1 split 0 5 pL Oven 135 C 15 min 15 C min to 270 C Detector FID 320 C or FID 320 C 0 5 pL cool on column oven track 70 C 2 min 25 C min to 150 C 3
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