Nitrite and nitrates are usually used in the production of meat products as food additives even though they pose a secondary risk. In this study, the residues of nitrite and nitrate ions in 366 processed meat products distributed in Seoul were analyzed using ion chromatographs and UV spectrophotometers. In all tested products, the residues of nitrite were below 70 mg/kg, which met the processing standard and component specification for livestock products.
Evaluation of nitrite ions, revealed a mean concentration of 7.1 - 11.9 mg/kg in hams, sausages, and bacons, while higher ratios of nitrite were found in other types of products. Among the studied processed meat products, at least 60% of hams and sausages had indications of nitrite, as did 90% of bacons and dry meats. No spiced meat and less than 10% of crushed meat had indications of nitrite. However, all dried meats showed below 1 mg/kg, regardless of whether they had indications of nitrite. Up to 9.7 mg/kg of nitrite was detected in the products with no indication of nitrite, and 14.6% of all products had at least 1 mg/kg of nitrite. This can be attributed to the reduction of residual nitrate ions in the products into nitrite ions.
A review of the concentrations of nitrate ions in processed meat products by type suggests that the mean concentration was 22.3 (maximum 110.2) mg/kg in hams, 31.8 (maximum 89.5) mg/kg in sausages, 16.4 (maximum 28.2) mg/kg in bacons, 16.8 (maximum 61.1) mg/kg in spiced meats, 20.2 (maximum 99.4) mg/kg in crushed meats, and 121.0 (maximum 216.5) mg/kg in dried meats. Therefore, dried meats showed much higher nitrate ion concentrations than other types of meat products; however, the residue of nitrite ions in actual dried meats was found to be lower than 1 mg/kg, suggesting that the concentrations of nitrate ions do not affect those of nitrite ions. However, a certain concentration of nitrate ions was observed even when nitrate ions were not used in the products, as nitrite ions were transformed into nitrate ions and nitrite ions were detected even the products with no indication of nitrite ions. Therefore, continuous monitoring and preparation of relevant standards of the use of nitrate in processed meat products are necessary.

Abstract
 서 론
 재료 및 방법
  재 료
  시약 및 기구
  시험방법
  통계분석
 결과 및 고찰
 REFERENCES

• Hee-Sun Chae(Seoul Metropolitan Government Reseach Institute of Public Health and Environment) Corresponding Author
• Yeon-Jae Park(Seoul Metropolitan Government Reseach Institute of Public Health and Environment)
• Ji-Eun Kim(Seoul Metropolitan Government Reseach Institute of Public Health and Environment)
• Dong-Kyu Kim(Seoul Metropolitan Government Reseach Institute of Public Health and Environment)
• Jong-Soo Kim(Food safety Division of Seoul Metropolitan Government)