Antonio Flavio Midio

Validated high-performance liquid chromatographic method for the determination of lamotrigine in human plasma

A high-performance liquid chromatographic (HPLC) procedure for lamotrigine was developed and validated. Lamotrigine (LTG) and an internal standard were extracted from plasma using liquid-liquid extraction under alkaline conditions into an organic solvent. The method was linear in the range 0.78-46.95 micromol/l, with a mean coefficient of correlation (r)> or =0.99923. The limit of detection (LOD) and limit of quantification (LOQ) were 0.19 and 0.58 micromol/l, respectively. Within- and between-run precision studies demonstrated C.V.<3% at all tested concentrations. LTG median recovery was 86.14%. Antiepileptic drugs tested did not interfere with the assay. The method showed to be appropriate for monitoring LTG in plasma samples.

Origin of blood ethanol in decomposed bodies

Problems related to blood contamination by other postmortem fluids in decomposed bodies (DB) make the interpretation of medicolegal blood alcohol levels (B EtOH) a very difficult task. So the aim of this paper is to show the utilization of vitreous humor (VH) as the biological fluid for an unequivocal determination of ethanol origin in DB for forensic purposes. Alcohol was determined in VH, blood (chest fluid-CF) and urine (Ur) collected from 27 DB in different states of putrefaction. A simple head-space gas-chromatographic method was used. In fifteen cases alcohol was found to be of endogenous production due to its absence in VH. In the twelve remainders, alcohol was detected in VH and CF in an atypical distribution. Examining the reliable scene and historical information together with the analytical data, ethanol origin in these cases was classified: endogenous production (3 cases), ingested (2 cases), both (2 cases), contaminated plus endogenous production (3 cases) and unable to determine (2 cases). According to the results obtained it was possible to conclude that alcohol analysis in VH is fundamental for determining the origin of ethanol detected in CF of DB.

Occurrence of aflatoxins B1, B2, G1 and G2 in cooked food components of whole meals marketed in fast food outlets of the city of Sa~o Paulo, SP, Brazil

Samples of cooked components of regular meals served at fast food outlets of the city of Sa~oPaulo, Brazil were analysed for aflatoxins B1, B2, G1 and G2. The 322 samples were composed of prepared traditional Brazilian and ethnic foods in which aflatoxins might be present. Thin-layer chromatography was used for separation of the compounds and their determination was achieved by both long wave UV light and fluorodensitometry. Aflatoxins were detected in 30 samples (9.31% of the total) in a range of 2.80 to 1323 ng/g for B1 + B2 + G1 + G2 with 90th percentiles of 158 (B1 + G1) and 258 (B1 + B2 + G1 + G2). Aflatoxin B1 was detected in all contaminated samples. The contamination levels and frequency of aflatoxins B1 and G1 in positive samples above 20 ng/g in this study are high, indicating that there is a certain degree of exposure of the population to the carcinogenic aflatoxin.

Exposição humana a trialometanos presentes em água tratada

Halogenated hydrocarbon compounds, some of them recognized as carcinogenic to different animal species can be found in drinking water. Chloroform, bromodichloromethane, dibromochloromethane and bromoform are the most important trihalomethanes found in potable water. They are produced in natural waters during chlorinated desinfection by the halogenation of precursors, specially humic and fulvic compounds. The review, in the MEDLINE covers the period from 1974 to 1998, presents the general aspects of the formation of trihalomethanes, sources of human exposure and their toxicological meaning for exposed organisms: toxicokinetic disposition and spectrum of toxic effects (carcinogenic, mutagenic and teratogenic).

The Possibilities of Hair Analysis in the Determination of Involuntary Doping in Sports

AbstractAlthough not yet fully recognised by international sporting committees, hair analysis in doping control may be a useful adjunct to drug testing of urine. It may permit access to retrospective information and the identification of banned substances, especially when exogenous abuse has to be distinguished from other forms of involuntary exposure to identical substances. Negative hair results coupled with positive urine samples may be used to draw conclusions of involuntary doping in sports whenever athletes claim not to have ingested any drug, identical substances are present in their environment or are normal constituents of food and beverages served to them immediately before the competition. Two cases are well described in the literature in which hair analyses were fundamental in documenting positive doping after urinalysis. In Brazil, 2 cases of athletes testing positive for banned substances caught our attention because of the possibility of involuntary doping; hair analysis, if performed, may have helped to clarify the results of the urinalysis.Despite the fact that it cannot be used for routine control and overrule positive urinalysis, hair analysis can detect long term exposure as well as those substances which are not excreted in urine. In the current International Olympic Committee (IOC) code, hair analysis is not yet considered useful even in special cases of doping control.