Rapid and simple determination of inulin in biological fluids by high-performance liquid chromatography with light-scattering detection.

We report a new high-performance liquid chromatography method developed for measuring inulin in plasma and urine using ion moderated partition chromatography and evaporative light-scattering detection. Samples are deproteinized with a zinc acetate and phosphotungstic acid solution and added with melezitose as an internal standard. The chromatographic separation is carried out in 16 min at a flow-rate of 0.

Rapid determination of creatinine in serum and urine by ion-pair high-performance liquid chromatography.

We report a simple and reliable high performance liquid chromatography method for measuring creatinine in serum and urine. The chromatographic run is performed on a C(18) column after protein precipitation with acetone and addition of cimetidine as an internal standard. The separation is carried out in 20 min at a flow rate of 0.

Simultaneous HPLC determination with light-scattering detection of lactulose and mannitol in studies of intestinal permeability in pediatrics.

We describe a new HPLC method for the simultaneous determination of lactulose and mannitol in urine, in which cation-exchange chromatography and evaporative light-scattering detection are used. The two sugars are orally administered for the estimation of intestinal permeability in children. Samples were purified by solid phase extraction on a C18 cartridge and subsequent addition of anion-exchange resin.

Is serum cystatin C a sensitive marker of glomerular filtration rate (GFR)? A preliminary study on renal transplant patients.

Human cystatin C is a basic low molecular mass protein (13,359 Dalton) freely filtered through the glomerulus and almost completely re-absorbed and catabolized by proximal tubular cells. We measured serum cystatin C in 38 kidney transplant patients (23 males, 15 females) aged between 6 and 32 years. To assess renal function, serum and urinary creatinine were also determined in all patients, and creatinine clearance was finally calculated.

Rapid determination of p-aminohippuric acid in serum and urine by high-performance liquid chromatography.

We report a simple and rapid HPLC procedure for measuring p-aminohippuric acid in serum and urine. After deproteinization with acetonitrile and addition of p-aminobenzoic acid as an internal standard, the chromatographic run is performed on a C18 column with the absorbance detector set at 275 nm. The separation is carried out in 10 min at a flow-rate of 1.

Matrix-assisted laser desorption/ionization mass spectrometry in milk science.

The protein content of several cow milks was investigated by matrix-assisted laser desorption/ionization (MALDI) mass spectrometry. In particular, milk from four different breeds of cow (Holstein Frisons, Brown Swiss, Jersey and Reggiana) at the same lactation stage and under the same feeding system were analysed and clear differences were found in their MALDI spectra. The various lactation stages were also investigated.