•Analysis of various alcoholic and non-alcoholic beverages.•The importance of the safety of drinks in for their consumers.•The innovative methods of DBS used to analysis.•Danger Date-rape Drugs (DRD) ...substances.•The concept of White Analytical Chemistry (WAC).
A new methodology for the detection of ketamine, flunitrazepam, and diazepam in beverage samples by the dried sample spot method was developed. The method is characterized by very low LODs in all tested types of beverages (100 ng/mL for ketamine, 25 ng/mL for flunitrazepam and diazepam) and great precision at the concentration of 100 ng/mL for all analytes. The significant advantages of this method are the consumption of fewer amount of samples and the possibility of securing the beverage samples on DBS cards at room temperature. The proposed method was evaluated by the innovative WAC approach according to Green Analytical Chemistry. The results of the evaluation indicate the best results of this method in terms of analytical quality compared to the other methods from the literature, however other aspects such as green chemistry and economical are also good. The DBS/MAE/LC-MS method could be used for qualitative analysis for drugs detection in cases of date-rape drugs analysis.
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Near-infrared diffuse reflectance spectroscopy （NIRDRS） has attracted more and more attention in analyzing the components in samples with complex matrices. However, to apply this technique to ...micro-analysis, there are still some obstacles to overcome such as the low sensitivity and spectral overlapping associated with this approach. A method for fast determination of bovine serum albumin （BSA） in micro-volume samples was studied using NIRDRS with sample spots and chemometric techniques. 10 p~L of sample spotted on a filter paper substrate was used for the spectral measurements. Quantitative analysis was obtained by partial least squares （PLS） regression with signal processing and variable selection. The results show that the correlation coefficient （R） between the predicted and the reference concentration is 0.9897 and the recoveries are in the range of 87.4%-114.4% for the validation samples in the concentration range of 0.61-8.10 mg/mL. These results suggest that the method has the potential to quickly measure proteins in micro-volume solutions.
Human 2-D PAGE Databases established at the Danish Centre for Human Genome Research are now available on the World Wide Web (http://biobase.dk/cgi-bin/celis). The databanks, which offer a ...comprehensive approach to the analysis of the human proteome both in health and disease, contain data on known and unknown proteins recorded in various IEF and NEPHGE 2-D PAGE reference maps (non-cultured keratinocytes, non-cultured transitional cell carcinomas, MRC-5 fibroblasts and urine). One can display names and information on specific protein spots by clicking on the image of the gel representing the 2-D gel map in which one is interested. In addition, the database can be searched by protein name, keywords or organelle or cellular component. The entry files contain links to other databases such as Medline, Swiss-Prot, PIR, PDB, CySPID, OMIM, Methabolic pathways, etc. The on-line information is updated regularly.
Analysis using two-dimensional (2D) gel electrophoresis of the
35S-methionine-labelled proteins synthesized by non-cultured total epidermal keratinocytes obtained from normal and psoriatic skin ...revealed 6 proteins that are strongly up-regulated (5 times or more) in psoriatic skin. These proteins are synthesized at albeit lower levels by keratinocytes from normal and normal-appearing (uninvolved) skin of psoriatic patients, and correspond to isoelectric focusing sample spot numbers 4311 (40.3 kDa), 4003 (12.4 kDa), 5008 (11.9 kDa), 3012 (11.6 kDa), 6016 (11.6 kDa) and 1015 (10;1 kDa) in the normal keratinocyte 2D gel protein database Celis et al, (1990) Electrophoresis, in press. These proteins are also detected in the labelling medium indicating that they are at least in part secreted. Given their striking regulatory behavior, these proteins may play a role in the pathogenesis of psoriasis.
Nuclear Factor IV (NFIV)is a heterodimeric DNA-binding protein from HeLa cells, recognizing molecular ends and is identical to the autoantigenic target Ku. We have identified the two NFIV/Ku ...subunits, by comigration, in the 2D-gel database of transformed human amnion cell (AMA) proteins. We observed that the large subunit or NFIV/Ku consists of at least 3 charge variants that correspond to SSP IEFs 5705 (81.2 kDa, p
I 5.74), 6707 (81.2 kDa, p
I 5.67) and 6706 (81.9 kDa, p
I 5.60) in the AMA catalogue. The relative amounts of the 2 major variants (IEFs 5705 and 6707) was dependent on the state of cell proliferation. Inhibition of DNA-synthesis by hydroxyurea also changed the relative levels of the variants, whereas aphidicolin or a thymidine block had no effect. These results suggest a possible role for NFIV/Ku in DNA replication.
We present a universal method to efficiently improve reproducibility and sensitivity of surface-assisted laser desorption/ionization time of flight mass spectrometry (SALDI-TOF MS). In this method, ...the Si pillar array with unique surface wettability is used as substrate for ionizing analyte. The Si pillar is fabricated based on the combination of photolithography and metal-assisted chemical etching, which is of hydrophilic top and hydrophobic bottom and side wall. Based on the surface wettability of the Si pillar, a droplet of an aqueous analyte solution can be confined on the top of the Si pillar. After evaporation of solvent, an analyte deposition spot is formed on the top of Si pillar. The visible size of the Si pillar allows the sample spot to be easily found. Meanwhile, the diameter of the Si pillar is smaller than that of the laser, allowing the observation of all analyte molecules under one laser shot. Therefore, the reproducibility and sensitivity are highly improved with this method, which allows for the quantitative analysis. Furthermore, this method is applicable for different analytes dissolved in water, including amino acids, dye molecules, polypeptides, and polymers. The application of this substrate is demonstrated by analyzing real samples at low concentration. It should be a promising method for sensitive and reproducible detection for SALDI-TOF MS.
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La investigación en producción animal requiere la recolección total de orina, para estimar la excreción de compuestos nitrogenados y derivados púricos, lo cual trae grandes dificultades, siendo ...necesario buscar técnicas alternas. El objetivo de este trabajo fue determinar el volumen de orina de vacas Holstein por colecta total con arneses y por muestras puntuales ”spot”, utilizando la excreción de creatinina como marcador interno y evaluar la variación en la excreción diaria de creatinina utilizando colectas durante siete días. El volumen de orina observado (colecta total) y el estimado (muestra spot) fueron comparados por una prueba de medias de datos apareados (5% de probabilidad). La comparación entre días de colecta se realizó mediante un modelo mixto con medidas repetidas en el tiempo, del mismo animal (efecto aleatorio) y día de evaluación (efecto fijo). Se utilizó el procedimiento MIXED y el comando REPEATED del programa SAS (2001). Para la correlación entre el volumen de orina observado y estimado se utilizó PROC CORR y para la regresión PROC REG de SAS (2001). La excreción de creatinina promedio fue de 29,89 mg/kg PV/día. No se encontró diferencia entre las dos técnicas. El volumen de orina obtenido fue 19,8 L y el estimado 19,7 L. Se encontró una alta correlación entre las dos técnicas (r=0,82; P<0,001). No hubo efecto del número de días sobre la excreción de creatinina. Se concluye que la toma de muestras puntuales de orina, es un buen estimador del volumen urinario y que 24 horas de recolección de orina son suficientes para determinar la excreción de creatinina con precisión.The research in animal production requires the total harvesting of tinkles to estimate the excretion of nitrogenated compounds and puric derivates, which brings great difficulties, doing necessary the search of alternating techniques. The objective of this work was to determine the volume of tinkles of Holstein cows by collects total with harness and the gathering samples spot using the excretion creatinine like internal marker and evaluate the variation in daily creatinine excretion using collections for seven days. A paired test (5% probability) was used to compare observed (total collection) and estimated (samples spot) urine volumes. Number of sampling days was compared by mixed model with repeated measures over time, the same animal (random effect) and day (fixed effects). Also was used the MIXED procedure and REPEATED command (SAS, 2001). The correlation between observed and estimated urine volume was performed by PROC CORR and regression was performed by PROC REG (SAS, 2001). The creatinine excretion average was 29.89 mg/kg of BW. It was not difference between the two techniques. The urine volume obtained was 19.8 L and the estimated urine volume was 19.7 L. There was a high correlation between the two techniques (r=0.82; P<0.001). Urinary excretion of creatinine was not affected by the number of urinary collection days. It was concluded that spot samples of urine, is a good estimator of the urinary volume and 24 hours of urine collection were required to accurate determine creatinine excretion
This prospective study was initiated to assess the significance of spot urine specimens (SU) for the metabolic evaluation of stone formers.
68 stone patients (51 males, 17 females) and 20 controls (9 ...males, 11 females) participated. On 3 consecutive days, urine was collected. Fasting (SU1) and postprandial (SU2) SU were obtained. From these, aliquots were taken, all the other urine was mixed to obtain 24-hour timed specimens (24hU). In all specimens, pH, specific gravity, creatinine, calcium, magnesium, phosphate, citrate, uric and oxalic acids were measured. The latter analytes were related to creatinine (mmol/g creatinine). Pearson correlation coefficients with their levels of significance and the day-to-day variation were calculated. Using the values in the control group, normal values (means +/- 2 SD) were established.
There was a significant correlation (p < 0.0001) between SU and 24hU for all parameters examined. The day-to-day variation of all analytes was considerable in SU and 24hU.
Despite a minor inaccuracy by relating parameters to creatinine, SU are sufficient in the routine metabolic evaluation of stone formers, since a third of all 24hU has to be rejected because of considerable collection errors. SU circumvent this problem. Because of the day-to-day variation, 3 SU should be obtained to overcome the doubtful significance of one single specimen.
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