title: Monitoring of nitrites and nitrates levels in leafy vegetables (spinach and lettuce): a contribution to risk assessment.
abstract: BACKGROUND
  Nitrites and nitrates are compounds considered harmful to humans and the major part of the daily intake of nitrates in foodstuffs is related to vegetable consumption. In this work, 150 leafy vegetables samples (75 spinach and 75 lettuce) were analysed in order to assess the levels of nitrites and nitrates. The analyses were carried out by a validated ion chromatography method and the samples with nitrate concentrations higher than legal limits and/or with quantifiable concentrations of nitrites were confirmed by an alternative ion chromatography method.
  
  
  RESULTS
  Nitrate levels higher than legal limits were detected both in spinach (four samples) and in lettuce (five samples). Nitrite residues were registered both at low concentrations--lower than 28.5 mg kg⁻¹ (12 spinach samples)--and at high concentrations, up to 197.5 mg kg⁻¹ (three spinach and one lettuce sample).
  
  
  CONCLUSIONS
  Considering the non-negligible percentage of 'not-compliant' samples for nitrates (6.0%), control is needed. Moreover, it is possible to suggest the introduction in the Communities Regulations of a 'maximum admissible level' for nitrites in leafy vegetables.
authors.forename: Marco
authors.initials: M
authors.lastname: Iammarino
authors.forename: Aurelia
authors.initials: A
authors.lastname: Di Taranto
authors.forename: Marianna
authors.initials: M
authors.lastname: Cristino
mesh_terms: D002273:Carcinogens / Q000032:analysis / Q000633:toxicity; D018556:Crops, Agricultural / Q000737:chemistry / Q000191:economics / Q000254:growth & development; D005506:Food Contamination / Q000331:legislation & jurisprudence; D005513:Food Inspection / Q000379:methods; D019983:Guideline Adherence; D017408:Guidelines as Topic; D006291:Health Policy; D006801:Humans; D007558:Italy; D007881:Legislation, Food; D018545:Lactuca / Q000737:chemistry* / Q000191:economics / Q000254:growth & development; D057230:Limit of Detection; D009566:Nitrates / Q000009:adverse effects / Q000032:analysis* / Q000633:toxicity; D009573:Nitrites / Q000009:adverse effects / Q000032:analysis* / Q000633:toxicity; D018515:Plant Leaves / Q000737:chemistry* / Q000254:growth & development; D015203:Reproducibility of Results; D018570:Risk Assessment; D018724:Spinacia oleracea / Q000737:chemistry* / Q000191:economics / Q000254:growth & development
chemical_list: D002273:Carcinogens; D009566:Nitrates; D009573:Nitrites