Laboratories which take in a high volume of aqueous samples will know that every sample is different. Samples can contain varying amounts of suspended particulates and/or sediment due to either the source of the water, or the collection technique. Still other samples may form precipitates under elevated pH conditions resulting in emulsions. These types of samples have historically proven very challenging when using solid phase extraction (SPE).

4790 Application Notes Disk English Environmental GC-MS Semi-Volatile Organics US EPA Method 3535A Water

Vial preparation: 1) Remember to add stir bar for efficient mixing. Catalysts, salts, or visible precipitate should be washed clear of head space and into solution. Particles adhering to glass head space could cause excessive heating increasing possibility of failure of vial. Stay within specified vial volume range (see diagram for proper filling).

Manuals & User Guides

Within each disk holder there is a support screen. The disk holders that we will cover are used with a broad range of Horizon products. The placement and condition of the support screen is critical to the functioning of these products.

Tech Tips

This poster describes the benefits of supported liquid extraction and highlights its use in removal of endogenous matrix components that cause ion suppression/enhancement (matrix effects) in LC-MS/MS analyses. HPLC 2014

96-well plate Clinical Column English Forensic LC-MS/MS Pharma Plasma Posters Urine Whole blood

Supported Liquid Extraction (SLE) is a 96-well high throughput technique that is analogous to traditional LLE.

Posters

This poster examines the use of ISOLUTE SLE+ columns as an alternative to SPE for the extraction and clean up of hair samples containing drugs of abuse. SLE was found to be a simple, faster alternative to SPE for this type of analysis. AAFS 2015

6-acetylmorphine (MAM) Benzoylecgonine Cocaine Cocaines Codeine Column Drugs of Abuse English Forensic GC-MS Hair Methadone Morphine Posters

This poster presents a novel method for the simultaneous extraction, derivatization and subsequent detection of both the traditional 25-hydroxy and the biologically active 1α,25-dihydroxy vitamin D metabolites in serum. ASMS2014

1, 25 Dihydroxyvitamin D 1a, 25-dihydroxy-vitamin D 1α, 25-dihydroxy-vitamin D 25-OH Vitamin D2 25-OH Vitamin D3 25-hydroxy-vitamin D 96-well plate Clinical English LC-MS/MS Posters Serum Vitamin D Vitamins

This poster describes the development and optimisation of the dual extraction method for Vitamin D metabolites using ISOLUTE SLE+.

1, 25 Dihydroxyvitamin D 1a, 25-dihydroxy-vitamin D 1α, 25-dihydroxy-vitamin D 25-OH Vitamin D2 25-OH Vitamin D3 25-hydroxy-vitamin D 96-well plate Clinical English LC-MS/MS Posters Serum Vitamin D Vitamins

Overview -Challanges: Chemical and Practical - Preliminary microwave Suzuki work - Single Reaction optimization -Prototype -Practical considerations -Conclusion and outlook

Solid-Phase Suzuki couplings using microwave irradiation have been performed. The reaction times were considerably shorter than those required using conventional heating conditions.

Application Notes

SOLUTION SOLUBLE : CH2Cl2 ,CH3CN, DMF, THF H2O REACTION homogeneous conditions ANALYSIS solution NMR analysis Mass Spectrometry

French

Leu-Enkephalin-amide (YGGFLNH2, Ca. MW = 554.65) was synthesized on the Rink amide ChemMatrix® resin at a scale of 0.5 mmol. Crude peptide (100 mg) was purified in duplicate using the Isolera Dalton equipped with a Biotage® SNAP KP-C18-HS 12g cartridge.

Customer Cases English

A branched peptidoglycan mimic and a tetra-branched antimicrobial peptide analogue were synthesized on a lysine scaffold using Biotage® Initiator+ Alstra™ microwave peptide synthesizer. These peptide modifications are challenging to synthesize and automate, however, the procedure was operationally simplified using Branches™.

Application Notes

It has recently been demonstrated that specific recognition of rhizobial bacteria by the signaling molecule Nod-factor receptor 5 (NFR5) relies on LysM domains. The LysM (lysine motif) domain is believed to be involved in the regulation of the interaction between plants and rhizobial bacteria to promote plant growth. The LysM domain is predicted to consist of two-α helices and a two-stranded anti-parallel β-sheet in a β-α-α-β structure and has been identified in NFR5 by sequence alignment of the crystal structure with the LysM domain of Bacillus subtilis ykuD.2 The synthesis of the C-terminal and the N-terminal regions of LysM domains provide significant challenges, this is presumably due to the formation of β-sheet like structures, which are known to pose problems for peptide chain assembly.

Application Notes

C-terminal peptide aldehydes are key components in oxime and hydrazine ligations and their synthesis is therefore very desirable. A well established method for the synthesis of C-terminal modified peptides including peptide aldehydes, is the backbone amide linker (BAL) strategy (Scheme 1).1 In this strategy, the first amino acid is anchored by reductive amination followed by acylation of the newly formed secondary amine. Thus, the growing peptide chain is anchored not through the C-terminal carboxyl but through a backbone amide nitrogen giving access to, in principle, any C-terminal modification.

Application Notes

A number of biologically active natural products contain N-methyl amino acids. N-Methyl amino acid containing peptides are potentially useful therapeutics as they have improved pharmacological properties such as such as proteolytic stability, bioavailability, lipophilicity, enhanced potency and receptor selectivity. The synthetic challenges associated with the synthesis of peptides containing consecutive N-methyl amino acids are well known1,2 and often require coupling reagents such as PyBOP3, HATU4 or even triphosgene4 to obtain high coupling yields. Syro Wave.

Application Notes English

One of the current challenges in peptide science is the assembly of long peptides and small proteins, which has to overcome the accumulation of side-reactions and the hurdles posed by so-called difficult sequences. During the synthesis of difficult sequences the peptide chain most likely becomes partially inaccessible typically due to the formation of secondary structures, especially β-sheets, which can inhibit acylation and deprotection during synthesis, resulting in truncated sequences. In addition, steric hindrance from β-branched amino acids can be a problem.

Application Notes English

We have demonstrated the capability of the Biotage® Initiator+ Alstra microwave peptide synthesizer to fully synthesize branched and cyclic peptides. The synthesis included specialized reactions of non-linear peptides and a high degree of purity was achieved. Furthermore, the Branches software feature provides an extensive overview for the scheduling and visualization of operations in order to make complex peptide modifications and is a great addition to the toolbox for the peptide chemist. Presented at EPS, Sofia, 2014.

Posters

Enzyme catalyses NAD dependant oxidation of inosine 5’-monophosphate IMP to xanthosine 5’-monophosphate (XMP)