1. 1 Analysis of the Isotope Patterns of Organic Sulfur Containing Compounds Ray A. Gross, Jr.

2. 2 Outline Theoretical Isotope Patterns Real Isotope Patterns New Method of Determining # S Atoms

3. 3 A/(A + 2) Isotope Ratios r 30:1 30 (3)28 (92)Silicon p 500:1 18 (0.2)16 (99.8)Oxygen q 22:1 34 (4.29)32 (94.93)Sulfur n 3:1 37 (24)35 (76)Chlorine m 1:1 81 (49)79 (51)Bromine Variable # atoms Ratio a/b ba Element

4. 4 Bromine Binomial Model for A + 2 Molecular Ion Intensities Ratio of 79 Br to 81 Br = 1:1 (a + b) m for Br m (a + b) 1 = 1a + 1b = 1:1 (a + b) 2 = 1a 2 + 2ab + 1b 2 = 1:2:1

5. 5 Chlorine Binomial Model for A + 2 Molecular Ion Intensities Ratio of 35 Cl to 37 Cl = 3:1 (3a + b) n for Cl n (3a + b) 1 = 3a + b = 3:1 (3a + b) 2 = 9a 2 + 6ab + 1b 2 = 9:6:1

6. 6 Sulfur A + 2 Binomial Ratio of 32 S to 34 S = 22:1 (22a + b) q for S q (22a + b) 1 = 22a + 1b = 22:1 (22a + b) 2 = 484a 2 + 44ab + 1b 2 = 484:44:1

7. 7 SqSq Sulfur Isotope Patterns Normalized to Highest Mass = 1 (22:1) q Ratio M/M + 2 S1S1 22 : 1 22 S2S2 484 : 44 : 1 11 S3S3 10648 : 1452 : 66 : 1 7.3 S4S4 234256 : 42592 : 2904 : 88 : 1 5.5 S5S5 5153632 : 1171280 : 106480 : 4840 : 110 : 1 4.4 S6S6 113379904 : 30921792 : 3513840 : 212960 : 7260 :132 :1 3.7

8. 8 SqSq Sulfur Isotope Patterns Normalized to M = 100 (22:1) q Ratio M/M + 2 (T) S1S1 100 : 4.5 22 (2) S2S2 100 : 9 : 0.2 11 (2) S3S3 100 : 14 : 0.6 : 0.01 7.3 (2) S4S4 100 : 18 : 1.2 : 0.03 : 0.0004 5.5 (2/3) S5S5 100 : 23 : 2.1 : 0.09 : 0.002 : 0.00002 4.4 (2/3) S6S6 100 : 27: 3 : 0.2 : 0.006 : 0.0001 : 0.0000008 3.7 (2/3)

9. 9 SqSq Ratio M/M + 2 (T) Yan Ratio M/M +2 (T) S1S1 22 (2)22.2 (2) S2S2 11 (2)11.1 (2) S3S3 7.3 (2)7.35 (2) S4S4 5.5 (2/3)5.52 (3) S5S5 4.4 (2/3)4.41 (3) S6S6 3.7 (2/3)3.68 (3)

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14. 14 Intensity Ratios for Real Compounds Containing Sulfur Number S Atoms Sample Size R2R2 R4R4 R 24 1>10012-23 2>1007.7-12 3475.59-7.4 4124.66-5.5350-7111-14 5103.68-4.7031-518.5-10.8 623.69-3.1221.5-31.57.09-8.71

15. 15

16. 16 Intensity Ratios for Real Compounds Containing Sulfur Number S Atoms R2R2 R4R4 R 24 112-23 27.7-12 35.59-7.4 44.66-5.5350-7111-14 53.68-4.7031-518.5-10.8 63.69-3.1221.5-31.57.09-8.71

17. 17

18. 18 Intensity Ratios for Real Compounds Containing Sulfur Number S Atoms R2R2 R4R4 R 24 112-23 27.7-12 35.59-7.4 44.66-5.5350-7111-14 53.68-4.7031-518.5-10.8 63.69-3.1221.5-31.57.09-8.71

19. 19

20. 20 Intensity Ratios for Real Compounds Containing Sulfur Number S Atoms R2R2 R4R4 R 24 112-23 27.7-12 35.59-7.4 44.66-5.5350-7111-14 53.68-4.7031-518.5-10.8 63.69-3.1221.5-31.57.09-8.71

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24. 24 Conclusion The intensity-ratio method is an efficient tool for determining small numbers of sulfur atoms in an unknown from its mass spectrum.

25. 25 Acknowledgments SDBS –http://www.aist.go.jp/RIODB/SDBS/cgi- bin/cre_index.cgi NIST –http://physics.nist.gov/PhysRefData/Compositions/in dex.html Yan –http://www.geocities.com/junhuayan/pattern.htm