Automatic flow-batch system for the sample treatment and determination of hydroxyproline in sausages.

In this study an automatic method for sample treatment and spectrophotometric determination of hydroxyproline in commercial sausages was developed. A flow-batch system that includes the steps of sample hydrolysis and determination of the analyte was designed. The method presents a linear range between 0.60 and 3.60 µg mL(-1) of hydroxyproline. A relative standard deviation of 1.68% was obtained from hydroxyproline standard solution (n=6, 1.20 µg mL(-1)) and the detection limit was 0.12 µg mL(-1). The sample throughput was 1 sample h(-1) while the reference method (AOAC) was carried out in about 17 h. This method employs 16 h of hydrolysis while in the proposed method the hydrolysis time was 15 min. For this purpose a pressure hydrolysis chamber with a low cost halogen lamp was used. The flow-batch system is simple and allows the use of both chambers (hydrolysis and detection) simultaneously. The obtained results with the flow-batch method are in good agreement with that obtained with the reference method. Moreover, it is good alternative to the quality control of meat products.

Synchronous fluorescence for simultaneous determination of hydroquinone and resorcinol in air samples.

Several phenolic compounds are present in tobacco smoke. They are formed from the pyrolysis of tobacco during the smoking process and all of them are toxic. Therefore, the determination of these compounds in air samples is important. A rapid, simple, and sensitive method using a synchronous spectrofluorimetry technique was developed to quantify hydroquinone and resorcinol simultaneously. One of the advantages of this method is the simple and rapid sampling technique, which uses water as the absorption solution of the analytes in the air sample. The precision of the method (%RSD) was 1.8% and the detection limits were 0.125 mg m(-3) and 0.292 mg m(-3) for hydroquinone and resorcinol, respectively.