Pyrazine, ethenyl-
- Formula: C6H6N2
- Molecular weight: 106.1252
- IUPAC Standard InChIKey: KANZWHBYRHQMKZ-UHFFFAOYSA-N
- CAS Registry Number: 4177-16-6
- Chemical structure:
This structure is also available as a 2d Mol file or as a computed 3d SD file
The 3d structure may be viewed using Java or Javascript. - Other names: Pyrazine, vinyl-; Vinylpyrazine; 2-Vinylpyrazine; Ethenylpyrazine
- Permanent link for this species. Use this link for bookmarking this species for future reference.
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- Other data available:
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Gas Chromatography
Go To: Top, References, Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
Data compiled by: NIST Mass Spectrometry Data Center, William E. Wallace, director
Van Den Dool and Kratz RI, non-polar column, temperature ramp
Column type | Active phase | I | Reference | Comment |
---|---|---|---|---|
Capillary | BPX-5 | 954. | Bredie, Mottram, et al., 2002 | 50. m/0.32 mm/0.5 μm, 60. C @ 5. min, 4. K/min, 250. C @ 20. min |
Capillary | BPX-5 | 946. | Ames, Guy, et al., 2001 | 50. m/0.32 mm/0.5 μm, He, 60. C @ 5. min, 4. K/min, 250. C @ 10. min |
Capillary | BPX-5 | 947. | Ames, Guy, et al., 2001, 2 | 50. m/0.32 mm/0.25 μm, He, 60. C @ 5. min, 4. K/min, 250. C @ 10. min |
Capillary | BPX-5 | 950. | Ames, Defaye, et al., 1997 | 50. m/0.325 mm/0.5 μm, He, 50. C @ 2. min, 4. K/min, 250. C @ 10. min |
Capillary | HP-1 | 905. | Zhang, Dorjpalam, et al., 1992 | 50. m/0.32 mm/1.5 μm, 2. K/min, 220. C @ 30. min; Tstart: 40. C |
Van Den Dool and Kratz RI, non-polar column, custom temperature program
Column type | Active phase | I | Reference | Comment |
---|---|---|---|---|
Capillary | CP Sil 8 CB | 946. | Martin and Ames, 2001 | 60. m/0.25 mm/0.25 μm, He; Program: 40C(2min) => 4C/min => 200C => 10C/min => 250C(15min) |
Capillary | CP-Sil8 | 946. | Martin and Ames, 2001, 2 | 60. m/0.25 mm/0.25 μm, He; Program: 40C(2min) => 4C/min => 200C => 10C/min => 250C (15min) |
Capillary | DB-5 | 947. | Parker, Hassell, et al., 2000 | 50. m/0.32 mm/0.5 μm, He; Program: oC(5min) => 60C/min => 60C (5min) => 4C/min => 250C |
Capillary | BPX-5 | 947. | Bredie, Mottram, et al., 1998 | 50. m/0.32 mm/0.5 μm, He; Program: OC (5min) => 60C/min => 60C(5min) => 4C/min => 250C |
Capillary | DB-5 | 926. | Beal and Mottram, 1994 | 30. m/0.32 mm/1.0 μm, He; Program: 5 0C (0.5 min) -> (1 min) 60 0C (5 min) 4 0C/min -> 250 0C |
Van Den Dool and Kratz RI, polar column, temperature ramp
Column type | Active phase | I | Reference | Comment |
---|---|---|---|---|
Capillary | DB-Wax | 1434. | Pozo-Bayon M.A., Ruiz-Rodriguez A., et al., 2007 | 30. m/0.25 mm/0.5 μm, He, 40. C @ 5. min, 4. K/min, 250. C @ 15. min |
Capillary | DB-Wax | 1438. | Pozo-Bayon M.A., Ruiz-Rodriguez A., et al., 2007 | 30. m/0.25 mm/0.5 μm, He, 40. C @ 5. min, 4. K/min, 250. C @ 15. min |
Capillary | PEG-20M | 1438. | Shimoda, Nakada, et al., 1997 | 60. m/0.25 mm/0.25 μm, He, 2. K/min, 230. C @ 60. min; Tstart: 50. C |
Capillary | DB-Wax | 1438. | Shimoda, Shiratsuchi, et al., 1996 | 60. m/0.25 mm/0.25 μm, He, 2. K/min, 230. C @ 60. min; Tstart: 50. C |
Capillary | CP-WAX 57CB | 1416. | Baltes and Mevissen, 1988 | He, 50. C @ 5. min, 2. K/min; Column length: 50. m; Column diameter: 0.24 mm; Tend: 210. C |
Normal alkane RI, non-polar column, temperature ramp
Column type | Active phase | I | Reference | Comment |
---|---|---|---|---|
Capillary | DB-5 | 940. | Fadel, Mageed, et al., 2006 | He, 60. C @ 5. min, 4. K/min; Column length: 60. m; Column diameter: 0.32 mm; Tend: 250. C |
Capillary | MDN-5 | 934. | van Loon, Linssen, et al., 2005 | 60. m/0.25 mm/0.25 μm, He, 40. C @ 4. min, 4. K/min, 270. C @ 5. min |
Capillary | MDN-5 | 935. | van Loon, Linssen, et al., 2005 | 60. m/0.25 mm/0.25 μm, He, 40. C @ 4. min, 4. K/min, 270. C @ 5. min |
Capillary | DB-1 | 912. | Chen and Ho, 1999 | 60. m/0.32 mm/1. μm, He, 2. K/min; Tstart: 40. C; Tend: 260. C |
Capillary | DB-1 | 923. | Chen, Wang, et al., 1998 | 60. m/0.32 mm/1. μm, He, 3. K/min; Tstart: 40. C; Tend: 260. C |
Capillary | DB-1 | 901. | Buttery, Ling, et al., 1997 | 30. C @ 25. min, 4. K/min, 200. C @ 20. min; Column length: 60. m; Column diameter: 0.25 mm |
Capillary | DB-1 | 906. | Lu, Yu, et al., 1997 | 60. m/0.32 mm/1. μm, He, 40. C @ 2. min, 2. K/min, 280. C @ 40. min |
Capillary | DB-1 | 901. | Buttery and Ling, 1995 | He, 30. C @ 25. min, 4. K/min, 200. C @ 20. min; Column length: 60. m; Column diameter: 0.25 mm |
Capillary | DB-1 | 922. | Yu and Ho, 1995 | 60. m/0.25 mm/1. μm, He, 40. C @ 5. min, 2. K/min, 260. C @ 60. min |
Capillary | DB-1 | 909. | Yu, Wu, et al., 1994 | 60. m/0.25 mm/1.0 μm, He, 40. C @ 5. min, 2. K/min, 260. C @ 60. min |
Capillary | DB-1 | 908. | Yu, Wu, et al., 1994, 2 | 60. m/0.25 mm/1. μm, He, 40. C @ 5. min, 2. K/min, 260. C @ 60. min |
Capillary | DB-1 | 900. | Flath, Matsumoto, et al., 1989 | 60. m/0.32 mm/0.25 μm, 4. K/min; Tstart: 50. C; Tend: 250. C |
Capillary | DB-1 | 901. | Flath, Matsumoto, et al., 1989 | 60. m/0.32 mm/0.25 μm, 4. K/min; Tstart: 50. C; Tend: 250. C |
Capillary | OV-101 | 907. | Mihara and Enomoto, 1985 | N2, 2. K/min; Column length: 50. m; Column diameter: 0.22 mm; Tstart: 80. C; Tend: 200. C |
Normal alkane RI, non-polar column, custom temperature program
Column type | Active phase | I | Reference | Comment |
---|---|---|---|---|
Capillary | CP Sil 5 CB | 907. | Counet, Callemien, et al., 2002 | 50. m/0.32 mm/1.2 μm; Program: 36C => 20C/min => 85C => 1C/min => 145C=3C/min => 250C(30min) |
Capillary | OV-1, SE-30, Methyl silicone, SP-2100, OV-101, DB-1, etc. | 907. | Waggott and Davies, 1984 | Hydrogen; Column length: 50. m; Column diameter: 0.32 mm; Program: not specified |
Normal alkane RI, polar column, temperature ramp
Column type | Active phase | I | Reference | Comment |
---|---|---|---|---|
Capillary | HP-Innowax | 1413. | Puvipirom and Chaisei, 2012 | 15. m/0.32 mm/0.50 μm, Helium, 3. K/min; Tstart: 40. C; Tend: 250. C |
Capillary | FFAP | 1447. | Budryn, Nebesny, et al., 2011 | 30. m/0.32 mm/0.50 μm, Nitrogen, 35. C @ 5. min, 4. K/min, 250. C @ 45. min |
Capillary | FFAP | 1447. | Nebesny, Budryn, et al., 2007 | 30. m/0.32 mm/0.5 μm, N2, 35. C @ 5. min, 4. K/min, 320. C @ 45. min |
Capillary | HP-Wax | 1467. | Sanz, Maeztu, et al., 2002 | 60. m/0.25 mm/0.5 μm, He, 40. C @ 6. min, 3. K/min; Tend: 190. C |
Capillary | HP-Wax | 1467. | Maeztu, Sanz, et al., 2001 | 60. m/0.25 mm/0.5 μm, He, 40. C @ 6. min, 3. K/min; Tend: 190. C |
Capillary | HP-Wax | 1467. | Sanz, Ansorena, et al., 2001 | 60. m/0.25 mm/0.5 μm, He, 40. C @ 6. min, 3. K/min; Tend: 190. C |
Capillary | DB-Wax | 1436. | Buttery, Orts, et al., 1999 | 30. C @ 4. min, 2. K/min, 170. C @ 60. min; Column length: 60. m; Column diameter: 0.32 mm |
Capillary | DB-Wax | 1436. | Buttery and Ling, 1998 | 30. C @ 4. min, 2. K/min, 170. C @ 30. min; Column length: 60. m; Column diameter: 0.25 mm |
Capillary | DB-Wax | 1429. | Wong and Bernhard, 1988 | He, 70. C @ 8. min, 2. K/min; Column length: 30. m; Column diameter: 0.25 mm; Tend: 160. C |
Capillary | Carbowax 20M | 1392. | Mihara and Enomoto, 1985 | N2, 2. K/min; Column length: 50. m; Column diameter: 0.22 mm; Tstart: 80. C; Tend: 200. C |
Capillary | Carbowax 20M | 1422. | Liardon and Ledermann, 1980 | H2, 2. K/min; Column length: 39. m; Column diameter: 0.30 mm; Tstart: 60. C; Tend: 220. C |
Capillary | Carbowax 20M | 1415. | Shibamoto and Russell, 1977 | 1. K/min; Column length: 100. m; Column diameter: 0.25 mm; Tstart: 70. C; Tend: 170. C |
Normal alkane RI, polar column, custom temperature program
Column type | Active phase | I | Reference | Comment |
---|---|---|---|---|
Capillary | Innowax | 1449. | Ito and Mori, 2004 | 30. m/0.25 mm/0.50 μm, Helium; Program: 40 0C (2 min) 10 0C/min -> 100 0C 3 0C/min -> 160 0C 5 0C/min -> 260 0C (10 min) |
Capillary | Carbowax 400, Carbowax 20M, Carbowax 1540, Carbowax 4000, Superox 06, PEG 20M, etc. | 1392. | Waggott and Davies, 1984 | Hydrogen; Column length: 50. m; Column diameter: 0.32 mm; Program: not specified |
References
Go To: Top, Gas Chromatography, Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
Bredie, Mottram, et al., 2002
Bredie, W.L.P.; Mottram, D.S.; Guy, R.C.E.,
Effect of temperature and pH on the generation of flavor volatiles in extrusion cooking of wheat flour,
J. Agric. Food Chem., 2002, 50, 5, 1118-1125, https://doi.org/10.1021/jf0111662
. [all data]
Ames, Guy, et al., 2001
Ames, J.M.; Guy, R.C.E.; Kipping, G.J.,
Effect of pH and temperature on the formation of volatile compounds in cysteine/reducing sugar/starch mixtures during extrusion cooking,
J. Agric. Food Chem., 2001, 49, 4, 1885-1894, https://doi.org/10.1021/jf0012547
. [all data]
Ames, Guy, et al., 2001, 2
Ames, J.M.; Guy, R.C.E.; Kipping, G.J.,
Effect of pH, temperature, and moisture on the formation of volatile compounds in glycine/glucose model systems,
J. Agric. Food Chem., 2001, 49, 9, 4315-4323, https://doi.org/10.1021/jf010198m
. [all data]
Ames, Defaye, et al., 1997
Ames, J.M.; Defaye, A.B.; Bates, L.,
The effect of pH on the volatiles formed in an extruded starch-glucose-lysine model system,
Food Chem., 1997, 58, 4, 323-327, https://doi.org/10.1016/S0308-8146(96)00171-9
. [all data]
Zhang, Dorjpalam, et al., 1992
Zhang, Y.; Dorjpalam, B.; Ho, C.-T.,
Contribution of peptides to volatile formation in the Maillard reaction of casein hydrolysate with glucose,
J. Agric. Food Chem., 1992, 40, 12, 2467-2471, https://doi.org/10.1021/jf00024a026
. [all data]
Martin and Ames, 2001
Martin, F.L.; Ames, J.M.,
Formation of Strecker aldehydes and pyrazines in a fried potato model system,
J. Agric. Food Chem., 2001, 49, 8, 3885-3892, https://doi.org/10.1021/jf010310g
. [all data]
Martin and Ames, 2001, 2
Martin, F.L.; Ames, J.M.,
Comparison of flavor compounds of potato chips fried in palmolein and silicone fluid,
J. Amer. Oil Chem. Soc., 2001, 78, 8, 863-866, https://doi.org/10.1007/s11746-001-0356-2
. [all data]
Parker, Hassell, et al., 2000
Parker, J.K.; Hassell, G.M.E.; Mottram, D.S.; Guy, R.C.E.,
Sensory and instrumental analyses of volatiles generated during the extrusion cooking of oat flours,
J. Agric. Food Chem., 2000, 48, 8, 3497-3506, https://doi.org/10.1021/jf991302r
. [all data]
Bredie, Mottram, et al., 1998
Bredie, W.L.P.; Mottram, D.S.; Guy, R.C.E.,
Aroma volatiles generated during extrusion cooking of maize flour,
J. Agric. Food Chem., 1998, 46, 4, 1479-1487, https://doi.org/10.1021/jf9708857
. [all data]
Beal and Mottram, 1994
Beal, A.D.; Mottram, D.S.,
Compounds contributing to the characteristic aroma of malted barley,
J. Agric. Food Chem., 1994, 42, 12, 2880-2884, https://doi.org/10.1021/jf00048a043
. [all data]
Pozo-Bayon M.A., Ruiz-Rodriguez A., et al., 2007
Pozo-Bayon M.A.; Ruiz-Rodriguez A.; Pernin K.; Cayot N.,
Influence of eggs on the aroma composition of a sponge cake and on the aroma release in model studies on flavored sponge cakes,
J. Agric. Food Chem., 2007, 55, 4, 1418-1426, https://doi.org/10.1021/jf062203y
. [all data]
Shimoda, Nakada, et al., 1997
Shimoda, M.; Nakada, Y.; Nakashima, M.; Osajima, Y.,
Quantitative comparison of volatile flavor compounds in deep-roasted and light-roasted sesame seed oil,
J. Agric. Food Chem., 1997, 45, 8, 3193-3196, https://doi.org/10.1021/jf970172o
. [all data]
Shimoda, Shiratsuchi, et al., 1996
Shimoda, M.; Shiratsuchi, H.; Nakada, Y.; Wu, Y.; Osajima, Y.,
Identification and sensory characterization of volatile flavor compounds in sesame seed oil,
J. Agric. Food Chem., 1996, 44, 12, 3909-3912, https://doi.org/10.1021/jf960115f
. [all data]
Baltes and Mevissen, 1988
Baltes, W.; Mevissen, L.,
Model reactions on roast aroma formation. VI. Volatile reaction products from the reaction of phenylalanine with glucose during cooking and roasting,
Z. Lebensm. Unters. Forsch., 1988, 187, 3, 209-214, https://doi.org/10.1007/BF01043341
. [all data]
Fadel, Mageed, et al., 2006
Fadel, H.H.M.; Mageed, M.A.A.; Lotfy, S.N.,
Quality and flavour stability of coffee substitute prepared by extrusion of wheat germ and chicory roots,
Amino Acids, 2006, https://doi.org/10.1007/s007260200008
. [all data]
van Loon, Linssen, et al., 2005
van Loon, W.A.M.; Linssen, J.P.H.; Legger, A.; Posthumus, M.A.; Voragen, A.G.J.,
Identification and olfactometry of French fries flavour extracted at mouth conditions,
Food Chem., 2005, 90, 3, 417-425, https://doi.org/10.1016/j.foodchem.2004.05.005
. [all data]
Chen and Ho, 1999
Chen, J.; Ho, C.-T.,
Comparison of volatile generation in serine/threonine/glutamine-ribose/glucose/fructose model systems,
J. Agric. Food Chem., 1999, 47, 2, 643-647, https://doi.org/10.1021/jf980771a
. [all data]
Chen, Wang, et al., 1998
Chen, J.; Wang, M.; Ho, C.-T.,
Volatile compounds generated from thermal degradation of N-acetylglucosamine,
J. Agric. Food Chem., 1998, 46, 8, 3207-3209, https://doi.org/10.1021/jf980129g
. [all data]
Buttery, Ling, et al., 1997
Buttery, R.G.; Ling, L.C.; Stern, D.J.,
Studies on popcorn aroma and flavor volatiles,
J. Agric. Food Chem., 1997, 45, 3, 837-843, https://doi.org/10.1021/jf9604807
. [all data]
Lu, Yu, et al., 1997
Lu, G.; Yu, T.-H.; Ho, C.-T.,
Generation of flavor compounds by the reaction of 2-deoxyglucose with selected amino acids,
J. Agric. Food Chem., 1997, 45, 1, 233-236, https://doi.org/10.1021/jf960609c
. [all data]
Buttery and Ling, 1995
Buttery, R.G.; Ling, L.C.,
Volatile flavor components of corn tortillas and related products,
J. Agric. Food Chem., 1995, 43, 7, 1878-1882, https://doi.org/10.1021/jf00055a023
. [all data]
Yu and Ho, 1995
Yu, T.-H.; Ho, C.-T.,
Volatile compounds generated from thermal reaction of methionine and methionine sulfoxide with or without glucose,
J. Agric. Food Chem., 1995, 43, 6, 1641-1646, https://doi.org/10.1021/jf00054a043
. [all data]
Yu, Wu, et al., 1994
Yu, T.-H.; Wu, C.-M.; Ho, C.-T.,
Meat-like flavor generated from thermal interactions of glucose and alliin or deoxyalliin,
J. Agric. Food Chem., 1994, 42, 4, 1005-1009, https://doi.org/10.1021/jf00040a032
. [all data]
Yu, Wu, et al., 1994, 2
Yu, T.-H.; Wu, C.-M.; Ho, C.-T.,
Volatile compounds generated from the thermal interaction of glucose and alliin or deoxyalliin in propylene glycol,
Food Chem., 1994, 51, 3, 281-286, https://doi.org/10.1016/0308-8146(94)90028-0
. [all data]
Flath, Matsumoto, et al., 1989
Flath, R.A.; Matsumoto, K.E.; Binder, R.G.; Cunningham, R.T.; Mon, T.R.,
Effect of pH on the volatiles of hydrolyzed protein insect baits,
J. Agric. Food Chem., 1989, 37, 3, 814-819, https://doi.org/10.1021/jf00087a053
. [all data]
Mihara and Enomoto, 1985
Mihara, S.; Enomoto, N.,
Calculation of retention indices of pyrazines on the basis of molecular structure,
J. Chromatogr., 1985, 324, 428-430, https://doi.org/10.1016/S0021-9673(01)81342-X
. [all data]
Counet, Callemien, et al., 2002
Counet, C.; Callemien, D.; Ouwerx, C.; Collin, S.,
Use of gas chromatography-olfactometry to identify key odorant compounds in dark chocolate. Comparison of samples before and after conching,
J. Agric. Food Chem., 2002, 50, 8, 2385-2391, https://doi.org/10.1021/jf0114177
. [all data]
Waggott and Davies, 1984
Waggott, A.; Davies, I.W.,
Identification of organic pollutants using linear temperature programmed retention indices (LTPRIs) - Part II, 1984, retrieved from http://dwi.defra.gov.uk/research/completed-research/reports/dwi0383.pdf. [all data]
Puvipirom and Chaisei, 2012
Puvipirom, J.; Chaisei, S.,
Contribution of roasted grains and seeds in aroma of oleang (Thai coffee drink),
Int. Food Res. J., 2012, 19, 2, 583-588. [all data]
Budryn, Nebesny, et al., 2011
Budryn, G.; Nebesny, E.; Kula, J.; Majda, T.; Krysiak, W.,
HS-SPME/GC/MS Profiles of convectively and microwave roasted Ivory Coast Robusta coffee brews,
Czech. J. Food Sci., 2011, 29, 2, 151-160. [all data]
Nebesny, Budryn, et al., 2007
Nebesny, E.; Budryn, G.; Kula, J.; Majda, T.,
The effect of roasting method on headspace composition of robusta coffee bean aroma,
Eur. Food Res. Technol., 2007, 225, 1, 9-19, https://doi.org/10.1007/s00217-006-0375-0
. [all data]
Sanz, Maeztu, et al., 2002
Sanz, C.; Maeztu, L.; Zapelena, M.J.; Bello, J.; Cid, C.,
Profiles of volatile compounds and sensory analysis of three blends of coffee: influence of different proportions of Arabica and Robusta and influence of roasting coffee with sugar,
J. Sci. Food Agric., 2002, 82, 8, 840-847, https://doi.org/10.1002/jsfa.1110
. [all data]
Maeztu, Sanz, et al., 2001
Maeztu, L.; Sanz, C.; Andueza, S.; de Peña, M.P.; Bello, J.; Cid, C.,
Characterization of espresso coffee aroma by static headspace GC-MS and sensory flavor profile,
J. Agric. Food Chem., 2001, 49, 11, 5437-5444, https://doi.org/10.1021/jf0107959
. [all data]
Sanz, Ansorena, et al., 2001
Sanz, C.; Ansorena, D.; Bello, J.; Cid, C.,
Optimizing headspace temperature and time sampling for identification of volatile compounds in ground roasted Arabica coffee,
J. Agric. Food Chem., 2001, 49, 3, 1364-1369, https://doi.org/10.1021/jf001100r
. [all data]
Buttery, Orts, et al., 1999
Buttery, R.G.; Orts, W.J.; Takeoka, G.R.; Nam, Y.,
Volatile flavor components of rice cakes,
J. Agric. Food Chem., 1999, 47, 10, 4353-4356, https://doi.org/10.1021/jf990140w
. [all data]
Buttery and Ling, 1998
Buttery, R.G.; Ling, L.C.,
Additional studies on flavor components of corn tortilla chips,
J. Agric. Food Chem., 1998, 46, 7, 2764-2769, https://doi.org/10.1021/jf980125b
. [all data]
Wong and Bernhard, 1988
Wong, J.M.; Bernhard, R.A.,
Effect of nitrogen source on pyrazine formation,
J. Agric. Food Chem., 1988, 36, 1, 123-129, https://doi.org/10.1021/jf00079a032
. [all data]
Liardon and Ledermann, 1980
Liardon, R.; Ledermann, S.,
volatile components of fermented soya hydrolysate. II. Composition of basic fraction,
Z. Lebensm. Unters. Forsch., 1980, 170, 3, 208-213, https://doi.org/10.1007/BF01042542
. [all data]
Shibamoto and Russell, 1977
Shibamoto, T.; Russell, G.F.,
A study of the volatiles isolated from a D-glucose-hydrogen sulfide-ammonia model system,
J. Agric. Food Chem., 1977, 25, 1, 109-112, https://doi.org/10.1021/jf60209a054
. [all data]
Ito and Mori, 2004
Ito, K.; Mori, M.,
Formation of pyrazines in aqueous maltose/glucose/fructose-glutamide model systems upon heating at below 100 0C,
Food Sci. Technol. Res., 2004, 10, 2, 199-204, https://doi.org/10.3136/fstr.10.199
. [all data]
Notes
Go To: Top, Gas Chromatography, References
- Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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