15 research outputs found
Analytical Profile of the Methods in Reactive Polymeric Solid Phase
This review is aimed at covering the recent advances and the present status of trace analysis methods based on in situ measurements in the reactive polymeric solid phase
Contribution to diagnostics/prognostics of tuberculosis in children. I. New methods of assaying zinc and simultaneously copper and zinc in diluted sera by flame atomic-absorption spectrometry
In an attempt to provide a reliable status of metal ions in children, new methods of analysis of children's sera are proposed. New flame atomic-absorption spectrometric (FAAS) methods are simple, cost- and time-effective and, above all, labor-, reagent- and sample-saving. Two methods were suggested: method A for simultaneous determination of Cu and Zn from 5-fold diluted sera, and method B, for assaying zinc alone in 10-fold diluted samples. Both methods are based on a single-step sample pretreatment (deproteinization with 3 mol dmā3 HCl). Method A uses a single-step calibration with a mixed standard. The main advantage of method B is an additional reduction in sample consumption. Both methods were fully validated against reference methods. Accuracy, sensitivity and precision have proven them to be comparable to the reference methods in terms of analytical performance, and applicable to analyses of children's sera
Contribution to diagnostics/prognostics of tuberculosis in children. II. Indicative value of metal ions and biochemical parameters in serum
In an attempt to provide a reliable status of metal ions in children, new methods of analysis of children's sera are proposed. New flame atomic-absorption spectrometric (FAAS) methods are simple, cost- and time-effective and, above all, labor-, reagent- and sample-saving. Two methods were selected andvalidated against reference methods: method A for simultaneous determination of Cu and Zn from 5-fold diluted sera, and method B, for assaying zinc alone in 10-fold diluted samples. Both methods are based on a single-step sample pretreatment (deproteinization with 3 mol dm-3 HCl). Method A uses a single-step calibration with a mixed standard. The main advantage of method B is an additional reduction in sample consumption. Both methods were fully validated; accuracy, sensitivity and precision have proven them to becomparable to the reference methods, in terms of analytical performance,and applicable to analyses of children's sera
Jednostavna i brza metoda odreÄivanja udjela ukupnih karotenoida u liofiliziranoj marelici (Prunus armeniaca L.) pomoÄu refleksne kolorimetrije i fotoakustiÄne spektroskopije
Photoacoustic spectroscopy (PAS) and reflectance colorimetry are suggested as new tools for the analysis of total carotenoids in lyophilized apricot powders. The data obtained by these two techniques from seven apricot cultivars were compared to those acquired by spectrophotometry and high-performance liquid chromatography (HPLC). Best correlations were found between the total carotenoid (TC) content (obtained by VIS spectrophotometry: 1.2ā3.4 mg per 100 g of fresh mass) and colorimetric index a* (a* represents the redness of the investigated sample), as well as either argon-ion laser- or xenon-lamp-based PAS. In all three cases linear correlations were comparable. However, according to the sensitivity and precision data, expressed via limit of detection (LOD) and measurement repeatability, the Xe-lamp-based PAS is a preferred approach, followed by colorimetric index a* and Ar-ion laser PAS. Both PAS methods exhibit practically the same Pearson\u27s correlation coefficient (R=0.987 and R=0.991) values. Nevertheless, residual sum of squares (RSS) and residual standard deviation of the linear regression (sy/x) differ markedly. For Xe-lamp-based PAS these parameters were much lower than in the case of Ar-ion laser PAS. Likewise, analysis imprecision amounted to relative standard deviation (RSD) of 1ā3 % for Xe-lamp PAS and 2ā6 % for Ar-ion laser PAS. On the other hand, as expected, the calibration sensitivity achieved for the PAS signal induced by an Ar-ion laser at 481 nm was substantially higher than that of a Xe-lamp at 470 nm. Nevertheless, according to much lower sy/x, the corresponding LOD for Xe-lamp PAS was still two times lower than that of Ar-ion-based laser PAS (0.59 vs. 1.10 mg per 100 g). Unlike this, Ar-ion laser PAS showed more favourable instrumental precision and standard error of the weighed mean when compared to the Xe-lamp PAS (0.1ā0.6 and 0.1ā0.3 % vs. 0.5ā8.0 and 0.4ā1.7 %, respectively). As far as colorimetric indices are concerned, only a* proved to be analytically useful; excellent R but rather modest RSS and sy/x resulted in LOD value of 0.70 mg per 100 g and acceptable analysis imprecision of up to 3 %. The outcome of this research provides sufficient amount of evidence that analytical methods such as reflectance colorimetry and PAS without the use of any chemicals are feasible for reliable quantification of total carotenoids in freeze-dried apricot homogenates.FotoakustiÄna spektroskopija (PAS) i refleksna kolorimetrija predložene su kao nove metode odreÄivanja udjela ukupnih karotenoida u liofiliziranom prahu marelice. Rezultati dobiveni ispitivanjem sedam kultivara marelice ovim dvjema tehnikama usporeÄeni su s onima dobivenim konvencionalnom vidljivom spektrofotometrijom i tekuÄinskom kromatografijom visoke djelotvornosti (HPLC). Najbolje su korelacije dobivene izmeÄu udjela ukupnih karotenoida (vidljivom je spektrofotometrijom utvrÄen udjel od 1,2 do 3,4 mg u 100 g svježe mase) i kolorimetrijskog indeksa a* (parametar crvenila ispitanog uzorka), te metodom PAS s argonskim laserom ili ksenonskom lampom kao izvorom zraÄenja. U sva su tri sluÄaja dobivene usporedljive linearne korelacije. MeÄutim, s obzirom na osjetljivost i preciznost rezultata izraženih pomoÄu granice detekcije i ponovljivosti mjerenja, najboljom se pokazala metoda PAS sa ksenonskom lampom, zatim kolorimetrijski indeks a* i naposljetku metoda PAS s argonskim laserom. Obje su metode PAS imale podjednake Pearsonove koeficijente korelacije (R=0,987 i R=0,991). Ipak, rezidualna suma kvadrata (RSS) i rezidualna standardna devijacija linijske regresije (sy/x) znaÄajno su se razlikovale. Za metodu PAS sa ksenonskom lampom ovi su parametri bili znatno manji nego za metodu PAS s argonskim laserom. TakoÄer, nepreciznost je metode izražena pomoÄu relativne standardne devijacije (RSD) bila od 1 do 3 % za metodu PAS sa ksenonskom lampom i od 2 do 6 % za metodu PAS s argonskim laserom. S druge je pak strane, kao Å”to je i bilo oÄekivano, kalibracijska osjetljivost postignuta za signal PAS induciran argonskim laserom pri 481 nm bila znatno niža od one dobivene ksenonskom lampom pri 470 nm. Ipak, zahvaljujuÄi bitno nižoj vrijednosti sy/x, granica detekcije metode PAS sa ksenonskom lampom (0,59 mg u 100 g) bila je dvostruko manja od one metode PAS s argonskim laserom (1,10 mg u 100 g). Nasuprot tomu, metoda PAS s argonskim laserom imala je bolju preciznost instrumenta (nepreciznost mjerenja od samo 0,1-0,6 %) i standardnu pogreÅ”ku ponderirane sredine (0,1-0,3 %), u usporedbi s metodom PAS sa ksenonskom lampom (0,5-8,0 % odnosno 0,4-1,7 %). MeÄu kolorimetrijskim indeksima samo je indeks a* bio koristan za analizu; odliÄne vrijednosti R, ali skromne vrijednosti RSS i sy/x rezultirale su granicom detekcije od 0,70 mg u 100 g i prihvatljivom nepreciznoÅ”Äu mjerenja od najviÅ”e 3 %. Rezultati ovog istraživanja pokazuju da se analitiÄke tehnike, poput refleksne kolorimetrije i fotoakustiÄne spektroskopije mogu primijeniti za pouzdano odreÄivanje udjela ukupnih karotenoida u liofiliziranim homogenatima marelice, i to bez uporabe reagenasa
Jednostavna i brza metoda odreÄivanja udjela ukupnih karotenoida u liofiliziranoj marelici (Prunus armeniaca L.) pomoÄu refleksne kolorimetrije i fotoakustiÄne spektroskopije
Photoacoustic spectroscopy (PAS) and reflectance colorimetry are suggested as new tools for the analysis of total carotenoids in lyophilized apricot powders. The data obtained by these two techniques from seven apricot cultivars were compared to those acquired by spectrophotometry and high-performance liquid chromatography (HPLC). Best correlations were found between the total carotenoid (TC) content (obtained by VIS spectrophotometry: 1.2ā3.4 mg per 100 g of fresh mass) and colorimetric index a* (a* represents the redness of the investigated sample), as well as either argon-ion laser- or xenon-lamp-based PAS. In all three cases linear correlations were comparable. However, according to the sensitivity and precision data, expressed via limit of detection (LOD) and measurement repeatability, the Xe-lamp-based PAS is a preferred approach, followed by colorimetric index a* and Ar-ion laser PAS. Both PAS methods exhibit practically the same Pearson\u27s correlation coefficient (R=0.987 and R=0.991) values. Nevertheless, residual sum of squares (RSS) and residual standard deviation of the linear regression (sy/x) differ markedly. For Xe-lamp-based PAS these parameters were much lower than in the case of Ar-ion laser PAS. Likewise, analysis imprecision amounted to relative standard deviation (RSD) of 1ā3 % for Xe-lamp PAS and 2ā6 % for Ar-ion laser PAS. On the other hand, as expected, the calibration sensitivity achieved for the PAS signal induced by an Ar-ion laser at 481 nm was substantially higher than that of a Xe-lamp at 470 nm. Nevertheless, according to much lower sy/x, the corresponding LOD for Xe-lamp PAS was still two times lower than that of Ar-ion-based laser PAS (0.59 vs. 1.10 mg per 100 g). Unlike this, Ar-ion laser PAS showed more favourable instrumental precision and standard error of the weighed mean when compared to the Xe-lamp PAS (0.1ā0.6 and 0.1ā0.3 % vs. 0.5ā8.0 and 0.4ā1.7 %, respectively). As far as colorimetric indices are concerned, only a* proved to be analytically useful; excellent R but rather modest RSS and sy/x resulted in LOD value of 0.70 mg per 100 g and acceptable analysis imprecision of up to 3 %. The outcome of this research provides sufficient amount of evidence that analytical methods such as reflectance colorimetry and PAS without the use of any chemicals are feasible for reliable quantification of total carotenoids in freeze-dried apricot homogenates.FotoakustiÄna spektroskopija (PAS) i refleksna kolorimetrija predložene su kao nove metode odreÄivanja udjela ukupnih karotenoida u liofiliziranom prahu marelice. Rezultati dobiveni ispitivanjem sedam kultivara marelice ovim dvjema tehnikama usporeÄeni su s onima dobivenim konvencionalnom vidljivom spektrofotometrijom i tekuÄinskom kromatografijom visoke djelotvornosti (HPLC). Najbolje su korelacije dobivene izmeÄu udjela ukupnih karotenoida (vidljivom je spektrofotometrijom utvrÄen udjel od 1,2 do 3,4 mg u 100 g svježe mase) i kolorimetrijskog indeksa a* (parametar crvenila ispitanog uzorka), te metodom PAS s argonskim laserom ili ksenonskom lampom kao izvorom zraÄenja. U sva su tri sluÄaja dobivene usporedljive linearne korelacije. MeÄutim, s obzirom na osjetljivost i preciznost rezultata izraženih pomoÄu granice detekcije i ponovljivosti mjerenja, najboljom se pokazala metoda PAS sa ksenonskom lampom, zatim kolorimetrijski indeks a* i naposljetku metoda PAS s argonskim laserom. Obje su metode PAS imale podjednake Pearsonove koeficijente korelacije (R=0,987 i R=0,991). Ipak, rezidualna suma kvadrata (RSS) i rezidualna standardna devijacija linijske regresije (sy/x) znaÄajno su se razlikovale. Za metodu PAS sa ksenonskom lampom ovi su parametri bili znatno manji nego za metodu PAS s argonskim laserom. TakoÄer, nepreciznost je metode izražena pomoÄu relativne standardne devijacije (RSD) bila od 1 do 3 % za metodu PAS sa ksenonskom lampom i od 2 do 6 % za metodu PAS s argonskim laserom. S druge je pak strane, kao Å”to je i bilo oÄekivano, kalibracijska osjetljivost postignuta za signal PAS induciran argonskim laserom pri 481 nm bila znatno niža od one dobivene ksenonskom lampom pri 470 nm. Ipak, zahvaljujuÄi bitno nižoj vrijednosti sy/x, granica detekcije metode PAS sa ksenonskom lampom (0,59 mg u 100 g) bila je dvostruko manja od one metode PAS s argonskim laserom (1,10 mg u 100 g). Nasuprot tomu, metoda PAS s argonskim laserom imala je bolju preciznost instrumenta (nepreciznost mjerenja od samo 0,1-0,6 %) i standardnu pogreÅ”ku ponderirane sredine (0,1-0,3 %), u usporedbi s metodom PAS sa ksenonskom lampom (0,5-8,0 % odnosno 0,4-1,7 %). MeÄu kolorimetrijskim indeksima samo je indeks a* bio koristan za analizu; odliÄne vrijednosti R, ali skromne vrijednosti RSS i sy/x rezultirale su granicom detekcije od 0,70 mg u 100 g i prihvatljivom nepreciznoÅ”Äu mjerenja od najviÅ”e 3 %. Rezultati ovog istraživanja pokazuju da se analitiÄke tehnike, poput refleksne kolorimetrije i fotoakustiÄne spektroskopije mogu primijeniti za pouzdano odreÄivanje udjela ukupnih karotenoida u liofiliziranim homogenatima marelice, i to bez uporabe reagenasa
Simultaneous determination of iron and copper in children's sera by FAAS
Predložena je nova jednostavna metoda plamene atomsko-apsorpcijske spektrometrije (FAAS), za simultano odreÄivanje željeza i bakra u serumu djece. Ona se temelji na predobradbi uzorka u jednom koraku (deproteinizacija s 3 mol Lā3 HCl u odnosu 1:1) i kalibraciji u jednom koraku sa standardom pripravljenim u 1.5 mol Lā3 HCl.
Tijekom optimizacije metode primijenjen je multifaktorski dizajnirani eksperiment. PreporuÄena metoda osigurava ispravnost, osjetljivost i preciznost usporedljivu onima referentnih metoda. Novi je pristup jednostavan i brz; on Å”tedi i vrijeme i reagense i uzorke, pri Äemu je potonje posebno važno u djeÄjoj dijagnostici.A new and simple flame atomic-absorption spectrometric (FAAS) method is proposed for simultaneous determination of iron and copper in children's sera. It is based on single-step sample pretreatment (deproteinization with 3 mol Lā1 HCl, ratio 1:1) and single-step calibration using 1.5 mol Lā1 HCl standard. During methodās optimization a short multifactorial design experiment was used. The proposed method assures accuracy, sensitivity and precision comparable to that of the reference methods. The new approach is simple and time-, labour- and serum-saving, the latter being especially important in pediatric diagnostics
Assaying Total Carotenoids in Flours of Corn and Sweetpotato by Laser Photoacoustic Spectroscopy
This study describes the application of the laser photoacoustic spectroscopy (PAS) for quantification of total carotenoids (TC) in corn flours and sweetpotato flours. Overall, thirty-three different corn flours and nine sweetpotato flours were investigated. All PAS measurements were performed at room temperature using 488-nm argon laser radiation for excitation and mechanical modulation of 9 and 30Ā Hz. The measurements were repeated within a run and within several days or months. The UVāVis spectrophotometry was used as the reference method. The concentration range that allows for the reliable analysis of TC spans a region from 1 to 40Ā mg kgā1 for corn flours and from 9 to 40Ā mg kgā1 for sweetpotato flours. In the case of sweetpotato flours, the quantification may extend even to 240Ā mg kgā1 TC. The estimated detection limit values for TC in corn and sweetpotato flours were 0.1 and 0.3Ā mg kgā1, respectively. The computed repeatability (nā=ā3ā12) and intermediate precision (nā=ā6ā28) RSD values at 9 and 30Ā Hz are comparable: 0.1ā17.1% and 5.3ā14.7% for corn flours as compared with 1.4ā9.1% and 4.2ā23.0% for sweetpotato flours. Our results show that PAS can be successfully used as a new analytical tool to simply and rapidly screen the flours for their nutritional potential based on the total carotenoid concentration
Correlation of trans-Lycopene Measurements by the HPLC Method with the Optothermal and Photoacoustic Signals and the Color Readings of Fresh Tomato Homogenates
The trans-lycopene content of fresh tomato homogenates was assessed by means of the laser photoacoustic spectroscopy, the laser optothermal window, micro-Raman spectroscopy, and colorimetry; none of these methods require the extraction from the product matrix prior to the analysis. The wet chemistry method (high-performance liquid chromatography) was used as the absolute quantitative method. Analytical figures of merit for all methods were compared statistically; best linear correlation was achieved for the chromaticity index a* and chroma C*
Analytical profile of the methods in reactive polymeric solid phase
This review is aimed at covering the recent advances and the present status of trace analysis methods based on in situ measurements in the reactive polymeric solid phase