Quantitative determination of atmospheric hydroperoxyl radical

• US 20060046302A1
• Filed: 08/30/2004
• Published: 03/02/2006
• Est. Priority Date: 08/30/2004
• Status: Active Grant

• Current Assignee: Brookhaven Science Associates, LLC (Government of the United States of America)
• Original Assignee: Brookhaven Science Associates, LLC (Government of the United States of America)
• Inventors: Zheng, Jun, Lloyd, Judith, Springston, Stephen R.
• Granted Patent: US 7,285,243 B2
• Time in Patent Office: Days
• US Class Current: 436/84
• CPC Class Codes: G01N 21/76 Chemiluminescence; Bioluminescence

Abstract

A method for the quantitative determination of atmospheric hydroperoxyl radical comprising: (a) contacting a liquid phase atmospheric sample with a chemiluminescent compound which luminesces on contact with hydroperoxyl radical; (b) determining luminescence intensity from the liquid phase atmospheric sample; and (c) comparing said luminescence intensity from the liquid phase atmospheric sample to a standard luminescence intensity for hydroperoxyl radical. An apparatus for automating the method is also included.

Claims

1. A method for the quantitative determination of atmospheric hydroperoxyl radical comprising:

(a) contacting a liquid phase atmospheric sample with a chemiluminescent compound which luminesces on contact with hydroperoxyl radical;

(b) determining luminescence intensity from the liquid phase atmospheric sample; and

(c) comparing said luminescence intensity from the liquid phase atmospheric sample to a standard luminescence intensity for hydroperoxyl radical.

2. The method according to claim 1 wherein the standard luminescence intensity for hydroperoxyl radical is known.

3. The method according to claim 2 wherein the standard luminescence intensity for hydroperoxyl radical is known by measuring the luminescence intensity of a quantitative standard of hydroperoxyl radical.

4. The method according to claim 3 wherein the quantitative standard is produced by exposing a substrate to irradiation from an irradiation source.

5. The method according to claim 4, wherein exposure of said substrate to the irradiation source produces a known amount of hydroperoxyl radical.

6. The method according to claim 5 wherein the irradiation results from a nuclear decay process.

7. The method according to claim 6 wherein the irradiation is gamma irradiation.

8. The method according to claim 7 wherein the gamma irradiation results from the nuclear decay of a cobalt-60 irradiating component.

9. The method according to claim 8 wherein the substrate is a solution comprising a formate salt and water.

10. The method according to claim 9 wherein the formate salt is sodium formate.

11. The method according to claim 10 wherein the substrate is a solution further comprising a metal ion binding agent.

12. The method according to claim 11 wherein the metal ion binding agent is ethylenediaminetetraacetic acid.

13. The method according to claim 12 wherein the quantitative standard of hydroperoxyl radical is produced by a process further comprising dilution of an initial quantitative standard of hydroperoxyl radical.

14. The method according to claim 13 wherein the dilution is a serial dilution.

15. The method according to claim 13 further comprising storing a diluted initial quantitative standard of hydroperoxyl radical at a temperature of approximately 0°

C.

16. The method according to claim 15 wherein dilution results in a quantitative standard of hydroperoxyl radical having a concentration of about 3 nanomolar hydroperoxyl radical concentration.

17. The method according to claim 16 wherein the initial quantitative standard of hydroperoxyl radical is diluted into a stabilizing solution.

18. The method according to claim 17 wherein the stabilizing solution is aqueous and alkaline.

19. The method according to claim 18 wherein the stabilizing solution contains non-irradiated formate.

20. The method according to claim 19 wherein the stabilizing solution has a pH of about 11.

21. The method according to claim 1 wherein the liquid phase atmospheric sample is produced by treating an atmospheric sample with a liquid phase scrubbant, wherein the liquid phase scrubbant is capable of dissolving atmospheric hydroperoxyl radical into said liquid phase scrubbant.

22. The method according to claim 21 wherein the liquid phase scrubbant is aqueous-based.

23. The method according to claim 22 wherein the liquid phase scrubbant is alkaline.

24. The method according to claim 23 wherein the liquid phase scrubbant has a minimum pH of about 9 and a maximum pH of about 11.

25. The method according to claim 24 wherein the liquid phase scrubbant has a pH of about 9 and contains a borax buffer.

26. The method of claim 25 wherein the borax buffer is in a concentration of about 1.25 mM.

27. The method according to claim 26 wherein the atmospheric sample is treated with a liquid phase scrubbant in combination with a scrubbing element.

28. The method of claim 27 wherein the scrubbing element is a coil.

29. The method of claim 28 wherein the coil is a glass coil.

30. The method according to claim 1 wherein the chemiluminescent compound is 2-methyl-6-phenyl-3,7-dihydroimidazo[1,2-a]pyrazin-3-one.

31. The method according to claim 1 wherein the chemiluminescent compound is 2-methyl-6-(p-methoxyphenyl)-3,7-dihydroimidazo[1,2-a]pyrazin-3-one.

32. The method according to claim 30 or 31 wherein the chemiluminescent compound is a component in a chemiluminescent reagent.

33. The method according to claim 32 wherein the chemiluminescent reagent comprises the chemiluminescent compound and a solvent capable of dissolving the chemiluminescent compound.

34. The method according to claim 33 wherein the solvent is an aqueous-based solvent.

35. The method according to claim 34 wherein the aqueous-based solvent is a 1:

100 volume by volume solvent mixture of ethanol to water.

36. The method according to claim 35 wherein the chemiluminescent reagent has a minimum pH of about 1 and a maximum pH of about 5.

37. The method according to claim 36 wherein the chemiluminescent reagent has a minimum pH of about 2 and a maximum pH of about 3.

38. The method according to claim 37 wherein the chemiluminescent reagent has a pH of about 2.3.

39. The method according to claim 38 wherein the chemiluminescent compound is in a minimum concentration of about 1 micromolar and a maximum concentration of about 30 micromolar in the chemiluminescent reagent.

40. The method according to claim 39 wherein the chemiluminescent compound is in a concentration of about 9 micromolar in the chemiluminescent reagent.

41. The method according to claim 1 wherein a combination of the liquid phase atmospheric sample and the chemiluminescent compound has a pH of about 3.

42. The method according to claim 1 wherein luminescence intensity is measured with a chemiluminescence detector.

43. The method according to claim 42 wherein the luminescence intensity is the luminescence intensity at a particular wavelength of light within a range of wavelengths of light wherein luminescence occurs.

44. The method according to claim 42 wherein the luminescence intensity is the sum of the luminescence intensities measured over a range of wavelengths of light wherein luminescence occurs.

45. The method according to claim 44 wherein the range of wavelengths of light is a range of visible wavelengths of light.

46. The method according to claim 45 wherein the range of visible wavelengths of light span about 380 to 700 nanometers.

47. The method according to claim 1 wherein the method for the quantitative determination of atmospheric hydroperoxyl radical is automated by use of a flow injection apparatus.

48. The method according to claim 1 wherein the liquid phase atmospheric sample is produced continuously by a continuous flow of atmosphere into a scrubbing station.

49. An apparatus for the quantitative determination of atmospheric hydroperoxyl radical comprising:

(i) a source of a liquid phase atmospheric sample which includes a conduit for directing said liquid phase atmospheric sample;

(ii) a source of a chemiluminescent compound in a reagent stream which includes a conduit for directing said reagent stream;

(iii) a contact zone connected for fluid flow to each said carrier stream conduit and reagent stream conduit whereby said liquid phase atmospheric sample is contacted with said chemiluminescent compound; and

(iv) a chemiluminescence detector which detects luminescence resulting from said contact.

50. The apparatus according to claim 49 further comprising a source of a carrier stream for carrying the liquid phase atmospheric sample.

51. The apparatus according to claim 50 wherein the carrier stream comprises a solvent capable of dissolving hydroperoxyl radical.

52. The apparatus according to claim 51 wherein the solvent is aqueous-based.

53. The apparatus according to claim 52 wherein the carrier stream is alkaline.

54. The apparatus according to claim 53 wherein the carrier stream further comprises a formate salt.

55. The apparatus according to claim 54 wherein the carrier stream has a minimum pH of about 9 and a maximum pH of about 11.

56. The apparatus according to claim 55 wherein the pH of the carrier stream is adjusted with a base.

57. The apparatus according to claim 56 wherein the base is sodium hydroxide.

58. The apparatus according to claim 57 wherein the formate salt is sodium formate.

59. The apparatus according to claim 53 wherein the carrier stream further comprises borax.

60. The apparatus according to claim 59 wherein the carrier stream has a pH of about 9.

61. The apparatus according to claim 49 wherein the reagent stream comprises a solvent capable of dissolving the chemiluminescent compound.

62. The apparatus according to claim 61 wherein the solvent is aqueous-based.

63. The apparatus according to claim 62 wherein the solvent is a 1:

100 volume by volume ethanol to water mixture.

64. The apparatus according to claim 63 wherein the reagent stream has a pH of about 1 to 3.

65. The apparatus according to claim 64 wherein the reagent stream has a pH of about 2.3.

66. The apparatus according to claim 65 wherein the chemiluminescent compound is 2-methyl-6-phenyl-3,7-dihydroimidazo[1,2-a]pyrazin-3-one or 2-methyl-6-(p-methoxyphenyl)-3,7-dihydroimidazo[1,2-a]pyrazin-3-one.

67. The method according to claim 66 wherein the chemiluminescent compound is in a minimum concentration of about 1 micromolar and a maximum concentration of about 30 micromolar in the chemiluminescent reagent.

68. The apparatus according to claim 67 wherein the chemiluminescent compound is in an amount of about 9 micromolar.

69. The apparatus according to claim 49 wherein the conduit for directing the carrier stream comprises a fluid pump coupled to a fluid director.

70. The apparatus according to claim 69 wherein the conduit for directing the reagent stream comprises a fluid pump coupled to a fluid director.

71. The apparatus according to claim 70 wherein the fluid directors are tubes.

72. The apparatus according to claim 71 wherein the fluid pump directs the carrier stream and reagent stream at specified flow rates.

73. The apparatus according to claim 72 wherein the flow rates are adjustable.

74. The apparatus according to claim 73 wherein the specified flow rates are independently about 0.5 to 3.0 milliliters per minute.

75. The apparatus according to claim 74 wherein the specified flow rates are independently about 1.0 to 1.5 milliliters per minute.

76. The apparatus according to claim 75 wherein the fluid pump is a peristaltic pump.

77. The apparatus according to claim 49 wherein the source of a liquid phase atmospheric sample comprises a scrubbing station.

78. The apparatus according to claim 77 wherein the scrubbing station comprises a chamber containing housing for a liquid phase scrubbant, said housing connected to an inlet for atmosphere, said housing connected to an air pump having an air outlet, said housing further containing means for delivery of the liquid phase scrubbant, and said housing connected to the conduit for directing the liquid phase atmospheric sample.

79. The apparatus according to claim 78 further comprising a scrubbing element.

80. The apparatus according to claim 79 wherein the scrubbing element comprises a coil.

81. The apparatus according to claim 80 wherein the coil is made of glass.

82. The apparatus according to claim 81 wherein the coil contains five to twenty rounds of coilings.

83. The apparatus according to claim 82 wherein the coil has means for adjusting the coil temperature.

84. The apparatus according to claim 83 wherein the means for adjusting coil temperature is by the flow of a cooling or heating liquid or gas housed within the coil.

85. The apparatus according to claim 78 wherein the liquid phase scrubbant comprises the carrier stream.

86. The apparatus according to claim 49 further comprising a mixing station wherein the carrier stream and reagent stream are mixed to form a liquid phase atmospheric sample-chemiluminescent compound mixture.

87. The apparatus according to claim 86 wherein the mixing station is within the chemiluminescence detector.

88. The apparatus according to claim 86 wherein the liquid phase atmospheric sample-chemiluminescent compound mixture has a pH of about 3.

89. The apparatus according to claim 49 further comprising electronics for processing the luminescence intensity or data acquisition.

90. The apparatus according to claim 89 wherein the electronics is a computer or computer system.