Sistema di purificazione dell'acqua Milli-Q® Reference
Prodotti consigliati
Panoramica
Specifiche tecniche
Informazioni per l’ordine
Documentation
Riferimenti bibliografici
| Panoramica dei riferimenti bibliografici | Applicazione | Codice d'identificazione nel Pub Med |
|---|---|---|
| Quantification of 2-hydrazinopyridine derivatized steroid hormones in fathead minnow (Pimephales promelas) blood plasma using LC-ESI+/MS/MS D. Hala, M.D. Overturf, L.H. Petersen, D.B. Huggett J. Chromatogr. B 879 591–598 2010 Mostra il sommario Fathead minnows (Pimephales promelas) comprise a species-of-choice for the hazard assessments of various environmental contaminants, including compounds capable of disrupting endocrine function. Towards this end, the use of liquid chromatography coupled with mass spectrometry (LC–MS) and/or tandem mass spectrometry (MS/MS) is gaining common use for the quantification of steroid hormones as biomarkers of endocrine stress in small-fish toxicological studies. In this work, 2- hydrazinopyridine (2-HP) was used to derivatize and quantify the physiologically relevant steroid hormones of: 17 -hydroxypregnenolone, progesterone, 11-ketotestosterone, 11-deoxycortisol and 17 ,20 -dihydroxypregnenone, in the blood plasma of male and female fathead minnows. Liquid chromatographic separation was achieved using a WatersTM Sunfire C18 column (2.1mm×50mm with a 3.5 m particle size) and Milli-Q water:methanol (both with 0.1% formic acid) mobile phase over a gradient of 15 min. All mass analyses were conducted using electrospray ionization in the positive mode with tandem mass spectrometry (ESI+/MS/MS). This is the first such application of 2-HP derivatization for the quantifications of the structurally and functionally diverse C19 androgen of 11-ketotestosterone; C21 progestogens of 17 -hydroxypregnenolone, progesterone and17 ,20 -dihydroxypregnenone; and C21 corticosteroid of 11-deoxycortisol, in fathead minnow blood plasma. The limits of detection (LOD) were set to the lowest calibration standard that gave a signal-to-background response of ≥3, and were: 0.16 ng/ml for progesterone, 0.63 ng/ml for 17 -hydroxypregnenolone, 11-deoxycortisol and 17 ,20 - dihydroxypregnenone, and 1.25 ng/ml for 11-ketotestosterone. This study demonstrates the application of 2-HP derivatization for the analysis of a variety of steroid hormones representative of endocrine function in a species of fish commonly used in toxicological studies. | ||
| Assessment of the acute toxicity of triclosan and methyl triclosan in wastewater based on the bioluminescence inhibition of Vibrio fischeri M. Farré, D. Asperger, L. Kantiani, S. González, M. Petrovic, D. Barceló Anal Bioanal Chem 390 1999–2007 2008 Mostra il sommario In this work, the contributions of triclosan and its metabolite methyl triclosan to the overall acute toxicity of wastewater were studied using Vibrio fischeri. The protocol used in this paper involved various steps. First, the aquatic toxicities of triclosan and methyl triclosan were determined for standard substances, and the 50% effective concentrations (EC50) were determined for these compounds. Second, the toxic responses to different mixtures of triclosan, methyl triclosan, and surfactants were studied in different water matrices, i.e., Milli-Q water, groundwater and wastewater, in order to evaluate (i) the antagonistic or synergistic effects, and (ii) the influence of the water matrices. Finally, chemical analysis was used in conjunction with the toxicity results in order to assess the aquatic toxicities of triclosan and its derivative in wastewaters. In this study, the toxicities of 45 real samples corresponding to the influents and effluents from eight wastewater treatment works (WWTW) were analyzed. Thirty-one samples were from a wastewater treatment plant (WWTP) equipped with two pilot-scale membrane bioreactors (MBR), and the influent and the effluent samples after various treatments were characterized via different chromatographic approaches, including solid-phase extraction (SPE), liquid chromatography coupled to tandem mass spectrometry (LC–MS/MS), and SPE coupled to gas chromatography–mass spectrometry (GC–MS). The toxicity was determined by measuring the bioluminescence inhibition of Vibrio fischeri. In order to complete the study and to extrapolate the results to different WWTPs, the toxicity to V. fischeri of samples from seven more plants was analyzed, as were their triclosan and methyl triclosan concentrations. Good agreement was established between the overall toxicity values and concentrations of the biocides, indicating that triclosan is one of the major toxic organic pollutants currently found in domestic wastewaters. | ||
| Extraction of extracellular polymeric substances from extreme acidic microbial biofilms A. Aguilera, V. Souza-Egipsy, P. San Martín-Úriz, R. Amils Appl Microbiol Biotechnol 78 1079–1088 2008 Mostra il sommario The efficiency of five extraction methods for extracellular polymeric substances (EPS) was compared on three benthic eukaryotic biofilms isolated from an extreme acidic river, Río Tinto (SW, Spain). Three chemical methods (MilliQ water, NaCl, and ethylenediamine tetraacetic acid [EDTA]) and two physical methods (Dowex 50.8 and Crown Ether cation exchange resins) were tested. The quality and quantity of the EPS extracted from acidic biofilms varied according to which EPS extraction protocol was used. Higher amounts were obtained when NaCl and Crown Ether resins were used as extractant agents, followed by EDTA, Dowex, and MilliQ. EPS amounts varied from approximately 155 to 478 mg g-1 of dry weight depending on the extraction method and biofilm analyzed. EPS were primarily composed of carbohydrate, heavy metals, and humic acid, plus small quantities of proteins and DNA. Neutral hexose concentrations corresponded to more than 90% of the total EPS dry weight. The proportions of each metals in the EPS extracted with EDTA are similar to the proportions present in the water from each locality where the biofilms were collected except for Al, Cu, Zn, and Pb. In this study, the extracellular matrix heavy metal sorption efficiencies of five methods for extracting EPS from eukaryotic acidic biofilms were compared. | ||
| A General Method for Constructing Optically Active Supramolecular Assemblies from Intrinsically Achiral Water-Insoluble Free-Base Porphyrins Y. Zhang, P. Chen, M. Liu Chem. Eur. 14 1793 – 1803 2008 Mostra il sommario We have developed a general method to construct optically active porphyrin supramolecular assemblies by using a simple air–water interfacial assembly process. The method involved the in situ diprotonation of the free-base porphyrins at the air–water interface and subsequent assembly under compression. We showed that two intrinsically achiral water-insoluble free-base porphyrin derivatives, 2,3,7,8,12,13,17,18-octaethyl-21H,23H-porphine (H2OEP) and 5,10,15,20-tetra-p-tolyl-21H,23H-porphine (H2TPPMe), could be diprotonated when spread onto a 2.4?M hydrochloric acid solution surface, and the Langmuir–Schaefer (LS) films fabricated from the subphase exhibited strong circular dichroism (CD) absorption, whereas those fabricated from pure Milli-Q water subphase did not. The experimental data suggested that the helical stacking of the achiral porphyrin building blocks was responsible for the supramolecular chirality of the assemblies. Interestingly, such a method was successfully applied to a series of other intrinsically achiral free-base porphyrins such as 5,10,15,20-tetrakis(4-methoxyphenyl)-21H,23H-porphine (H2TPPOMe), 5,10,15,20-tetraphenyl-21H,23H-porphine (H2TPP), 5,10,15,20-tetrakis(4-(allyloxy)phenyl)-21H,23H-porphine (H2TPPOA), and 5,10,15,20-tetrakis(3,5-dimethoxyphenyl)-21H,23H-porphine (H2TPPDOMe). A possible mechanism has been proposed. The method provides a facile way to obtain optically active porphyrin supramolecular assemblies by using intrinsically achiral water-insoluble free-base porphyrin derivatives. | ||
| LC/MS/MS structure elucidation of reaction intermediates formed during the TiO2 photocatalysis of microcystin-LR M. G. Antoniou, J. A. Shoemaker, A. A. de la Cruz, D. D. Dionysiou Toxicon 51 1103–1118 2008 Mostra il sommario Microcystin-LR (MC-LR), a cyanotoxin and emerging drinking water contaminant, was treated with TiO2 photocatalysts immobilized on stainless steel plates as an alternative to nanoparticles in slurry. The reaction intermediates of MC-LR were identified with mass spectrometry (MS) at pH of Milli-Q water (pHsq = 5.7). Eleven new [M+H]+ were observed in the liquid chromatography mass spectrometry (LC/MS) chromatogram with some of them giving multiple peaks. Most of these reaction intermediates have not been reported from previous studies employing TiO2 nanoparticles at acidic conditions (pH = 4.0). Investigating the effects of pH (for 3.0<pH<7.0), toxin adsorption and initial toxin concentration on the degradation efficiency of the TiO2 photocatalytic films showed that acidic conditions are preferable for the degradation. Combined with the limited surface area of the films and the absence of additional oxidants (i.e., H2O2) the degradation was slower and more intermediate steps were identified. Possible structures of the intermediates (formed at neutral pH) after analyzing the corresponding MS/MS spectra are reported. The collision-induced dissociation of the [M+H]+ of MC-LR and the intermediates 1011.5 and 1029.5 are discussed and possible fragmentation pathways and mechanisms are also proposed. Analysis of the MS/MS spectra indicates that the fragmentation of some amino acids is less favorable because of internal interaction with free groups of adjacent amino acids. The MS/MS spectra assisted in determining hydroxylation sites, by the formation or alteration of specific product ions such as m/z 599. | ||
| Differential expression of chicken hepatic genes responsive to PFOA and PFOS L.W.Y. Yeung, K.S. Guruge, N. Yamanaka, S. Miyazaki, P.K.S. Lam Toxicology 237 111–125 2007 Mostra il sommario The effects of PFOS and PFOA on the gene expression patterns of chickens that were exposed to either PFOS or PFOA at low doses were investigated with the use of microarray techniques. Twelve Genechip Chicken Genome Arrays were used to study hepatic gene expression in 6-week-old chickens (Gallus gallus) that were exposed to either PFOA (0.1, 0.5, or 5 mg/mL), PFOS (0.02 or 0.1 mg/mL), or a saline vehicle control (0.9% NaCl in Milli-Q water) via subcutaneous implantation of a 2 mL osmotic pump for 4 weeks or for 4 weeks with a further 4 weeks of depuration. Over 240 and 480 genes were significantly affected by PFOS after 4 weeks of exposure and after 4 weeks of exposure with a further 4 weeks of depuration, respectively and over 290 and 320 genes were significantly affected by PFOA, correspondingly. For PFOS, the genes that were affected after 4 weeks of exposure were mainly related to the transport of electrons and oxygen, and the metabolism of lipids and fatty acids; while the genes that were affected after 4 weeks of exposure with a further 4 weeks of depuration were mainly related to the transport of electrons and ions, and protein amino acid phosphorylation and proteolysis. For PFOA, the genes that were affected after 4 weeks of exposure were related to the transport of ions, lipids, and electrons and cytochromes; while the genes that were affected after 4 weeks of exposure with a further 4 weeks of depuration were related to protein amino acid phosphorylation and proteolysis, the transport of ions, and the metabolism of fatty acids and lipids. The results also showed that the gene expression patterns between chickens that were treated with PFOS and those that were treated with PFOA were different, which points to the importance of the separate evaluation of the toxicities of PFOS and PFOA. Specifically, the gene expressions of CYP8B and NOV were studied. | ||
| Aligned Nanocables: Controlled Sheathing of CuO Nanowires by a Self-Assembled Tubular Glycolipid Y. Zhou, S. Kamiya, H. Minamikawa, T. Shimizu Adv. Mater 19 4194–4197 2007 Mostra il sommario Aligned nanocables, consisting of CuO nanowire cores and lipid nanotube shells, are prepared by sheathing an aligned array of CuO nanowires with a self-assembled tubular glycolipid (see figure). The sheath thickness of the nanocable is tunable by changing the incubation temperature of the lipid on the CuO nanowire. | ||
| Simultaneous determination of trace levels of ethylmercury and methylmercury in biological samples and vaccines using sodium tetra(n-propyl)borate as derivatizing agent D. Gibičar, M. Logar, N. Horvat, A. Marn-Pernat, R. Ponikvar, M. Horvat Anal Bioanal Chem 388 329–340 2007 Mostra il sommario Because of increasing awareness of the potential neurotoxicity of even low levels of organomercury compounds, analytical techniques are required for determination of low concentrations of ethylmercury (EtHg) and methylmercury (MeHg) in biological samples. An accurate and sensitive method has been developed for simultaneous determination of methylmercury and ethylmercury in vaccines and biological samples. MeHg and EtHg were isolated by acid leaching (H2SO4–KBr–CuSO4), extraction of MeHg and EtHg bromides into an organic solvent (CH2Cl2), then back-extraction into Milli-Q water. MeHg and EtHg bromides were derivatized with sodium tetrapropylborate (NaBPr4), collected at room temperature on Tenax, separated by isothermal gas chromatography (GC), pyrolysed, and detected by cold-vapour atomic fluorescence spectrometry (CV AFS). The repeatability of results from the method was approximately 5–10% for EtHg and 5–15% for MeHg. Detection limits achieved were 0.01 ng g-1 for EtHg and MeHg in blood, saliva, and vaccines and 5 ng g-1 for EtHg and MeHg in hair. The method presented has been shown to be suitable for determination of background levels of these contaminants in biological samples and can be used in studies related to the health effects of mercury and its species in man. This work illustrates the possibility of using hair and blood as potential biomarkers of exposure to thiomersal. | ||
| A thermo extraction–UV/Vis spectrophotometric method for total iodine quantification in soils and sediments B. S. Gilfedder, F. Althoff, M. Petri, H. Biester Anal Bioanal Chem 389 2323–2329 2007 Mostra il sommario Iodine in soils and sediments is a difficult element to analyze due to its volatility in acidic conditions. Traditionally it has been quantified using neutron activation analysis techniques, which, unfortunately, requires access to a nuclear reactor. We present here a simple method for solid-phase iodine analysis by thermo extraction at 1000°C and quantification by UV/Vis photometry. Samples are combusted in an oxygen stream and trapped in Milli-Q water. The extracts are then quantified by an As3+–Ce4+ spectrometric method whereby iodide catalyzes the oxidation of As3+ to As5+ and reduction of Ce4+ to Ce3+. Three standard reference materials were analyzed with excellent recoveries (97–113%) and RSDs (<5%). Moreover, the detection limit was less than 50 ng absolute iodine with a confidence limit of 95%. When applied to carbonate-rich samples from sediment traps deployed in Lake Constance we found very low iodine levels (0.8–2 mg kg-1). Despite the low concentrations, the precision of the method was consistently better than 5% RSD. However, the method needed to be slightly modified for organic and iodine-rich sediments (20–30% organic carbon) from a lake in the Black Forest by increasing the oxygen flow rate and decreasing the combustion time. Using the modified method we were able to achieve RSDs lower than 5%. | ||
| Ultraperformance Liquid Chromatography-Tandem Mass Spectrometry Analysis of Stimulatory Drugs of Abuse in Wastewater and Surface Waters M. Huerta-Fontela, M. Teresa Galceran, F. Ventura Anal. Chem. 79 3821-3829 2007 Mostra il sommario Ultraperformance liquid chromatography coupled to electrospray tandem mass spectrometry was used for the rapid and simultaneous analysis of 15 stimulatory drugs in water. Cocaine, amphetamine-related compounds, LSD, ketamine, PCP, fentanyl, and metabolites, among the controlled drugs, and nicotine, caffeine, and their metabolites, among the noncontrolled drugs, were studied. Chromatographic separation was achieved in less than 4.5 min, with improved peak resolution and sensitivity. Identification and quantification of the compounds of interest was performed by selected reaction monitoring, using an electrospray ionization source. Isotope dilution (except for paraxanthine) was used for quantitation. Quality parameters of the method were established, and limits of quantification were obtained for controlled drugs in surface waters from 0.1 to 3.1 ng/L and in wastewaters from 0.2 to 4.0 ng/L. Run-to-run and day-to-day precisions were evaluated in different water matrixes (Milli-Q water, surface water, wastewater). To assess the presence of these drugs in real water samples, the optimized method was applied to the analysis of wastewater and surface river water. The analysis of several samples from wastewater treatment plants in northeast Spain revealed the presence of drugs such as cocaine and amphetamine-related compounds, in both influent and effluent samples. Cocaine metabolite and MDMA (ecstasy) were also found in surface waters while nicotine and caffeine were detected in all the analyzed samples. The results obtained demonstrate that the presence of these drugs in the aquatic media must be considered a matter of environmental concern. |
Prodotti e applicazioni correlate
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Sistema per la produzione di acqua ultrapura Milli-Q® EQ 7000Sistema per l’acqua ultrapura di Tipo 1 per le applicazioni di laboratorio più sensibiliPer saperne di più >> |
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Categorie
| Lab Water Purification > Milli-Q® Type 1 Ultrapure Water Systems |
Il sistema Milli-Q® Reference produce acqua di Tipo 1 specifica per un'ampia gamma di settori della ricerca e rende l'acqua ultrapura comodamente disponibile in qualunque laboratorio. È stato progettato per l’alimentazione con acqua pretrattata.
Acqua Milli-Q® • Purificazione ottimizzata
Per ottenere acqua ultrapura di qualità Milli-Q®, è stata pienamente ottimizzata la sequenza di purificazione. L'acqua viene sottoposta a trattamento attraverso cartucce di purificazione Q-Gard® e Quantum®, fino a raggiungere una resistività di 18,2 MΩ.cm a 25°C e livelli di TOC inferiori a 5 ppb. Quindi, viene fatta ricircolare attraverso un anello fino all’erogatore, dove un Application Pak rimuove specificamente i contaminanti critici per i Suoi esperimenti. È disponibile un'ampia gamma di cartucce di purificazione e di Application-Pak tra cui scegliere in base alle proprie necessità.
In tutte le cartucce di purificazione Milli-Q® viene utilizzata la resina a scambio ionico vergine Jetpore®, prodotta esclusivamente per i sistemi Milli-Q®. Selezionata per le sue prestazioni eccezionali, questa resina è in grado di catturare, grazie alle sue capacità cinetiche, anche le specie ioniche con carica più debole. Le cartucce Q-Gard® e Quantum® incorporano entrambe la tecnologia RFID che consente di visualizzare istantaneamente i parametri di funzionamento della cartuccia e garantisce un funzionamento ottimale e sicuro del sistema, offrendo, nello stesso tempo, la piena tracciabilità.
Comodità, semplice erogazione e facile manutenzione
Utilizzando l'erogatore del sistema Milli-Q® Reference:
- si risparmia tempo, grazie alla funzione volumetrica che consente di erogare automaticamente il volume d'acqua richiesto
- si preparano le soluzioni senza fatica, grazie all'erogatore rimovibile di semplice impiego. Esso è stato ideato in modo da poterlo adattare all'altezza ed alla forma di tutta la vetreria di laboratorio.
Lo schermo grafico visualizza qualità dell’acqua e stato del sistema, garantendo che il sistema funzioni opportunamente e fornisca le condizioni operative migliori per i successivi esperimenti. Una Guida di riferimento rapida inserita nello sportello del sistema Milli-Q® Reference rappresenta uno strumento utile per ulteriori informazioni. La facilità di sostituzione delle cartucce, una lampada UV di lunga durata ed i tempestivi messaggi di allerta per la manutenzione, permettono al sistema di funzionare senza intoppi tutto l'anno.
Le e-Solution Millitrack® offrono per il sistema Milli-Q® Reference un controllo potenziato della gestione delle informazioni, oltre a funzioni di accesso remoto alla dashboard e di archiviazione elettronica a lungo termine. Inoltre, una gamma completa di servizi, assistenza alla convalida compresa, è fornita dai tecnici certificati Merck Millipore, utilizzando apparecchiature calibrate e Guide alla Convalida.
Certificati di qualità
Per una totale fiducia nel sistema Milli-Q® Reference, esso è fornito di Certificato di Calibrazione per i dispositivi di misura della temperatura e della resistività integrati e di Certificato di Conformità attestante che esso è stato fabbricato e testato, una volta assemblato, seguendo le Procedure Operative Standard aziendali. Inoltre, tutti i consumabili del sistema Milli-Q® Reference vengono forniti completi di Certificato di Qualità. Il sito produttivo è certificato ISO® 9001 v.2000 e ISO® 14001.
Specifiche dell’acqua
Acqua ultrapura Milli-Q® Reference (Tipo 1)
| Resistività compensata a 25 °C1 | 18,2 MΩ•cm |
| TOC2 | ≤ 5 ppb |
| Particelle (> 0,22 µm)3 | < 1 particella/ml |
| Batteri3,4 | < 0,01 UFC/ mL |
| Pirogeni (endotossine)4 | < 0,001 EU/ml |
| RNasi4 | < 1 pg/ml |
| DNasi4 | < 5 pg/ml |
| Portata | Fino a 2 L/min |
| 1 La resistività può essere visualizzata anche senza compensazione della temperatura, come richiesto dalla USP 2 Nelle condizioni di test appropriate 3 Con filtro finale Millipak® 4 Con cartuccia per il trattamento finale Biopak® Si tratta di valori tipici (convalidati utilizzando per l'alimentazione acqua Elix®) che potrebbero variare in base alla natura ed alla concentrazione dei contaminanti nell'acqua d'alimentazione. |
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A richiesta, è disponibile una relazione sulla conformità dell'acqua Milli-Q® Reference agli standard qualitativi stabiliti per l'acqua di Tipo 1 dalle norme ASTM®, ISO® 3696 e CLSI® ed ai requisiti definiti per l'acqua purificata dalle farmacopee USA ed europea.
Acqua d’alimentazione
| Qualità dell'acqua d'alimentazione | Acqua Elix®, RiOs™, distillata o DI con conducibilità < 100 µS/ cm e TOC < 50 ppb |
| Raccordo per l'alimentazione dell'acqua | Gas M da ½” |
| Pressione dell'acqua d'alimentazione* | 0 - 0,3 bar |
| Temperatura dell'acqua d'alimentazione | 5 - 35 °C |
| * Se la pressione dell'alimentazione è superiore a 0,3 bar, è necessario installare a monte del sistema un regolatore di pressione; pressioni comprese tra 0 e 0,2 bar sono compatibili con il sistema, ma la portata dell'acqua purificata potrebbe essere ridotta. | |
Specifiche del sistema
| Dimensioni (alt. x largh. x prof.) | 713 x 413 x 458 mm |
| Peso in esercizio | 19,5 kg |
| Distanza massima dell’erogatore remoto | 750 mm |
| Lunghezza del cavo d’alimentazione elettrica | 290 mm |
| Tensione d’alimentazione | 100 - 250 V ± 10% |
| Frequenza dell'alimentazione elettrica | 50 - 60 Hz ± 10% |
| Connessione dati | Ethernet (RJ45) |
Sicurezza
Il sistema Milli-Q® Reference è stato esaminato da un ente indipendente ed accreditato per quanto riguarda la conformità alle direttive CEE sulla sicurezza e la compatibilità elettromagnetica. Su richiesta, è possibile consultare la relazione. Il sistema Milli-Q® Reference viene fabbricato utilizzando componenti e metodologie raccomandati da UL e reca il marchio cUL. La registrazione può essere verificata nel sito web UL (http://www.ul.com).