ve To develope a new graphite furnace atomic absorption spectrophotometric (GFAAS) method for determination of cobalt in cosmetics. Methods Samples were digested by HNO3-HCl and microwave. The use of a new matrix modifier, (NH4)2 HPO4-ascorbic acid as a matrix, could effectively improve the shape of peak and eliminate the matrix interferences.The best determination conditions, such as the procedure of sample digestion, the measurement parameters were defined in this assay. Results The characteristic concentration, linear range, re-covery rate and coefficient of variation were 1.2?g/L, 0 -40?g/L, 100.16% ~102.01% and 1.82%-3.26% re-spectively. Conclusion Application of matrix modifier (NH4)2 HPO4-ascorbic acid for determination of Co with GFAAS, was easy and presented good repeatibility.

OBJECTIVETo explore the diagnostic value of MRI and SPECT in early postburn brain edema in severely burned dogs.

METHODSTwenty-six mongrel dogs were randomized into control (n = 6) and burned groups in which every 5 dogs were allotted to each of following time points: 6, 12, 18 and 24 postburn hours (PBHs). The dogs in burn groups were inflicted with 50% TBSA of III degree skin burn and were infused with 5% glucose solution after 6 PBHs, so that severe early postburn brain edema was produced. MRI and SPECT were employed to observe dynamically the brain of dogs in all groups. The results were collected and compared with one another.

RESULTSThe results indicated that with MRI brain morphological change of early brain edema could be shown as early as within 12 PBH and diffuse brain edema became more obvious with elapse of time. The changes might be difficult to be found by MRI when T(1)WISIR decreased below 10%. T(2)WI SIR increased by 8.29% at 24 PBH with blurred demarcation between the brain gray and white matters. There was diffused and progressive nuclide ((99)TCm-ECD) concentration in the brain tissue as shown by SPECT at 6 PBH. The radio-nuclide taking ratio increased significantly after 12 PBH, especially at 24 PBH (P < 0.01) when compared with that before burn.

CONCLUSIONCombined application of MRI and SPECT could evidently increase sensitivity and specificity in the diagnosis of early postburn brain edema.

Animals ; Brain Edema ; diagnosis ; diagnostic imaging ; Burns ; complications ; Dogs ; Magnetic Resonance Imaging ; Male ; Tomography, Emission-Computed, Single-Photon