Enzymatic proteolysis and in situ digestion as strategies to determine Cs and Sr in fish by tungsten coil atomic emission spectrometry

Autor(es)

Santos, Luana N. ^[1] ; Donati, George L. ^[1] ; Calloway, Jr., Clifton P. ^[2] ; Jones, Bradley T. ^[3] ; Nobrega, Joaquim A. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Fed Sao Carlos, Dept Chem, Grp Appl Instrumental Anal, BR-13560970 Sao Carlos, SP - Brazil

^[2] Winthrop Univ, Dept Chem, Rock Hill, SC 29733 - USA

^[3] Wake Forest Univ, Dept Chem, Winston Salem, NC 27109 - USA

• Tipo de documento: Artigo Científico
• Fonte: Journal of Analytical Atomic Spectrometry; v. 27, n. 12, p. 2082-2087, 2012.
• Citações Web of Science: 5

Resumo

Papain is employed to pre-digest and homogenize fish slurries which are directly placed on a tungsten coil atomizer and digested in situ with an oxidizing mixture of HNO3 and H2O2. Both Cs and Sr are determined in different fish samples by tungsten coil atomic emission spectrometry (WCAES) with limits of detection of 0.07 and 0.15 mu g l(-1), respectively. Sample aliquots of 50 mu l are dried, digested/pyrolyzed and atomized using a 400 W miniature solid-state constant current power supply and a Visual Basic temperature control program. The portable WCAES instrumental setup is composed of a small metallic atomization cell, a 2.54 cm diameter fused silica lens and a hand-held charge coupled device-based spectrometer. Tungsten filaments extracted from 24 V, 250 W commercially available light bulbs are used as atomizers. The method accuracy is demonstrated by comparing WCAES results with values obtained by ICP OES. No statistically significant differences are observed between the results from each different method at a 95% confidence level. Recovery tests are also carried out for Cs and values between 100 and 110% are obtained. The method precision is calculated to be 6.8 and 7.3% for 2.5 mu g l(-1) of Cs and 100 mu g l(-1) of Sr (n = 10), respectively. The method described is simple, fast and efficient, offering an interesting alternative for applications in food safety control and determinations in the field. (AU)

• Processo FAPESP: 10/50238-5 - Determinacao de fosforo, enxofre e silicio em biodiesel usando espectrometro de massa acoplado ao plasma induzido com interface de colisao e reacao
• Beneficiário: George Luis Donati
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 07/51448-0 - Construcao e aplicacao analitica de espectrometro de emissao atomica com atomizacao eletrotermica em filamento de tungstenio.
• Beneficiário: Joaquim de Araújo Nóbrega
• Modalidade de apoio: Auxílio à Pesquisa - Regular