U.S. Reporter 29.5

Analytical Reagents & Standards, Supelco Reporter 29.5

High-Purity Solvents for UHPLC, LC-MS and GC-Headspace
Broader Selection of Quality Pesticide Standards Now Available from Sigma-Aldrich

High-Purity Solvents for UHPLC, LC-MS and GC-Headspace back to top
Shyam Verma
shyam.verma@sial.com

Solvent impurities are the most common cause of extraneous peaks and unstable baseline. Background noise is typically caused by impurities that enter the system from the sample, by leaching from system components (bottles, tubes, valves, vials, etc.), and from solvents and additives. Solvent-derived impurities do not condition out over time and can interfere in the analysis in multiple ways, such as: a) collect on head of the column and elute as a distinct peak or as baseline rise, b) cause general elevation in baseline, lowering sensitivity of analysis, c) foul or damage sensitive instrument components and d) cause cluster ion formation that prevents reliable identification and quantification. For minimizing or eliminating these issues, sensitive tests like UHPLC, LC-MS and GC Headspace requires the use of highly pure solvents and additives.

Our Fluka brand has added another product line to the family of high-purity CHROMASOLV® solvents, blend and additives for sensitive UHPLC applications. This new product line is tested for UHPLC performance, including gradient applications, under both UV and MS detection. These solvents and reagents, designed for use in these sensitive analytical methods, as well as the sensitive GC-headspace analysis, are manufactured with utmost precision and are tested under strict quality control requirements.
Figure 1. UV drift of the solvent baseline resulting from a gradient application of LC-MS Ultra CHROMASOLV Acetonitrile/water (red) compared with LC-MS grade Acetonitrile/water (blue)


Figure 2. Reserpine spectrum measured in Methanol (Cat. No. 34966); no signals should be greater than [M+H]+=609 (100 ppb reserpine; ESI, positive mode)
LC-MS Ultra CHROMASOLV Grade Solvents
These solvents are tested for performance in UHPLC gradient separations, as well as UV, and positive and negative ion mode MS detection (Figure 1). Compared to standard LC-MS grade solvents, this new grade has significantly lower baseline and fewer minor peaks. In general, these solvents offer the following advantages:
  • High purity for extremely low detection limits under any detection mode together with UHPLC
  • Tested for UHPLC-MS
  • Suitability tested by UHPLC-MS TOF
  • High lot-to-lot reproducibility
  • Reliable data, high performance and eliminate system downtime

LC-MS CHROMASOLV Solvents
The LC-MS CHROMASOLV solvents undergo 34 distinct and relevant tests to ensure solvent requirements of sensitive LC-MS analyses. Some of the most important features are:
  • Application-tested for LC-MS using the reserpine tests (Figure 2)
  • Very low level of inorganic and metal ions for high sensitivity spectra
  • Particle/non-volatile compound-free (maintain system integrity)
  • Low gradient baseline with your own optimized protocols
  • Significantly reduced level of phthalate contaminants

Pre-Blended LC-MS Solvents
Our pre-blended solutions of the most commonly-used LC-MS mobile phases are prepared with precision and unsurpassed attention to quality. Using the precisely blended solvents eliminates time-consuming mobile phase preparation, and can eliminate lost sample information and instrument downtime caused by impure mobile phase. A special formulation assures that no precipitation or decomposition of the additive occurs under normal laboratory conditions. These high-quality preblended solvents offer:
  • Time savings
  • Accurate composition
  • Minimized baseline and artifacts

LC-MS Mobile Phase Additives
Fluka brand offers a wide range of high-purity additives for LC-MS applications that are already tested for LC-MS application. These high-purity additives offer many advantages for both small and large molecule analysis.
  • Acids, bases, volatile salts and sodium sources
  • High purity and LC-MS application tested
  • Improved ionization and resolution
  • Sodium ion additives for uniform/stable molecular ions

GC-Headspace Solvents
An important application of GC-Headspace (GC-HS) is for the determination of residual volatile organic impurities (OVIs) in active drug substances or excipients in drug formulations. The allowable limits for these OVIs are listed by the United States Pharmacopeia (USP), European Pharmacopoeia (Ph.Eur.) and in the International Conference on Harmonization (ICH) guidelines. In the GC-HS method, the composition and purity of the sample solvent have significant effects on the recovery and quality of the chromatogram. Sigma-Aldrich/Fluka developed high-purity solvents specifically for GC-HS applications (Figure 3). These solvents, microfiltered at 0.2 µm and packed under inert gas, offer the following benefits:
  • High purity and longer shelf life
  • Cleaner blanks and improved analyte recoveries
  • No major interference peaks in elution range
  • Specifications matching USP, Ph.Eur. & ICH guidelines
Figure 3. Fluka’s High Purity Headspace Grade vs an Organic Synthetic Grade - Using GC-MS and SPME on DMSO
1. Pentane
2. Hexane
3. Isopropyl ether
4. Dimethylpentane
5. Isooctane
6. Diisobutylene
7. Trimethylcyclopentane
8. Dimethylcyclopentanone



The organic synthesis grade showed many peaks not detected in the GC-HS grade DMSO. The GC-HS grade produced a cleaner headspace blank and showed no major interference peaks in the elution range of the target analytes.

Fluka Brand headspace solvents are manufactured under strictly controlled processes, including micro-filtration and packaging under an inert atmosphere. This ensures their suitability for meeting the demands of headspace analysis.

Featured Products
LC-MS Ultra CHROMASOLV Solvents and Additives Qty Cat. No.
Acetonitrile ≥ 99.9%* 1 L, 2 L 14261
Methanol ≥ 99.9% 1 L, 2 L 14262
Water   1 L, 2 L 14263
Trifluoroacetic acid ≥ 99.0% ** 1 mL, 2 mL 14264
Formic acid ≥ 98%** 1 mL, 2 mL 14265
Ammonium formate ** 25 g 14266
Ammonium acetate ** 25 g 14267
* tested for UHPLC-MS
** suitable for UHPLC-MS
LC-MS CHROMASOLV Solvents Cat. No.
Water 39253
Acetonitrile 34967
Methanol 34966
2-Propanol 34965
Ethyl acetate 34972
LC-MS CHROMASOLV Solvent Blends Cat. No.
Acetonitrile with 0.1% TFA 34976
Methanol with 0.1% TFA 34974
Acetonitrile with 0.1% formic acid 34668
Acetonitrile with 0.1% ammonium acetate 34669
Acetonitrile with 0.1% formic acid and 0.01% TFA 34676
Water with 0.1% TFA 34978
LC-MS CHROMASOLV Mobile Phase Additives Cat. No.
Trifluoroacetic acid, puriss p.a. 40967
Formic acid, puriss p.a. 56302
Acetic acid, puriss p.a. 49199
Ammonium formate, puriss p.a. 55674
GC Headspace Solvents Qty Cat. No.
N,N-Dimethylacetamide, puriss. p.a. 1L 44901
Dimethyl sulfoxide, puriss. p.a. 1L 51779
Cyclohexanone, puriss. p.a. 1L 68809
1-Methyl-2-pyrrolidinone, puriss. p.a. 1L 69337
N,N-Dimethylformamide, puriss. p.a. 1L 51781
1,3-Dimethyl-2-imidazolidinone, puriss. p.a. 1L 67484
Water 1L 53463


Broader Selection of Quality Pesticide Standards Now Available from Sigma-Aldrich back to top
 
Sigma-Aldrich now provides analysts with one of the broadest offerings of standards for pesticide analysis available. Recent additions to our portfolio include proficiency testing samples, NIST traceable certified reference materials and matrix standards for monitoring sample preparation methods. These products, along with our 2000 plus pesticide standards, allow Sigma-Aldrich to fulfill the needs of many laboratories, including those that are ISE/ISO 17025 accredited.

NEW! Certified Reference Materials (CRMs)
Our newly expanded pesticide standard line includes certified reference materials in the form of neats and matrix standards.

Fluka TraceCERT® pesticide CRMs are certified in a double accredited laboratory fulfilling ISO/IEC 17025 and ISO Guide 34 using high performance quantitative NMR (HP-qNMR®) for content determination with direct traceability to NIST and SI. This measurement technique for purity offers a superior level of accuracy, calculated uncertainties and lot-specific values when compared to other CRMs in the marketplace.

Sigma-Aldrich RTC pesticide CRMs are available as either “real world” soil or sediment natural matrices or natural matrices in which selected analytes have been fortified to give analytical profiles that meet the needs of the market. A robust statistical program is used in determining the certified values of these CRMs, utilizing data developed from multi-laboratory analysis supported by in-house data. Most CRMs are method specific and are supplied with certificates that show an uncertainty, expanded uncertainty confidence interval, and a prediction value, in addition to the mean value and standard deviation from the mean.

Neat and Single-Component Solutions
We stock more than 1800 isotope-labeled and non-isotope labeled neat and single component solutions for shipment every day, including Fluka brand PESTANAL® grade standards. PESTANAL grade products are high-purity standards of herbicides, pesticides and their metabolites. Most have a purity >99%. Each PESTANAL standard is formulated for single use to reduce waste and packaged in glass ampuls. A batch specific assay for each standard is provided on the product label, and details of this assay are found on the certificate of analysis accompanying each purchase.

Second Source Products
To complement our PESTANAL grade standards, we provide Chem Service brand pesticide and pesticide metabolite standards. Many other second source pesticide standards are available from within Sigma-Aldrich. It is our goal to provide these products to you in a timely manner, making it convenient to order all your chromatography supplies from Sigma-Aldrich. Standards are shipped with documentation and expiration dates. 

Multi-Component Calibration Mixtures
Analysts performing multi-residue pesticide analyses can select from a variety of Supelco brand pesticide calibration mixtures for their application. These quantitative mixtures eliminate the time and money associated with sourcing individual raw materials, preparing the mix, and then disposing of unused hazardous materials.

Manufacturing and testing information is available for each Supelco brand calibration mixture in the form of a data packet. Each data packet documents the rigorous analytical methods used to verify raw material identity and purity, and provides verification of analyte purity and final concentration accuracy. Data packets are free of charge.

The composition of Sigma-Aldrich RTC Proficiency Testing Samples and Certified Reference matrix standards will vary from lot-to-lot. This is because these products are prepared from natural matrices; some are fortified.

NEW! Proficiency Test Samples
Through Sigma-Aldrich RTC, accredited ISO 17025 testing laboratories can now source certified soil, water and sludge proficiency test (PT) samples to evaluate their laboratory’s competency for performing pesticide analyses and calibration. Laboratories can choose to participate in our quarterly or semiannual PT programs, or simply purchase PT samples.

The advantages of choosing Sigma-Aldrich RTC PTs include:
  • Most PT samples are supplied in duplicate. The duplicate can be used to report additional methods or be retained as a QC standard, using the study values.
  • Advanced tracking – methods, analysts, accreditation and equipment can be reported for the same analyte at no extra charge
  • Evaluation reports can be sent to your Accreditation Authority (AA) for no additional charge.


Custom Standard Formulation Services
We recognize that a stock product may not always be appropriate for your applications. That’s why we have dedicated staff ready to formulate, test, and package pesticide calibration standards according to your exact specifications. Our chemists will gladly discuss stability and solubility concerns with you, and make suggestions where needed to improve the quality of your purchase. If you are interested in a customized pesticide standard, please feel free to contact us by email: customstandards@sial.com. Or, use the quote request form at our website sigma-aldrich.com/standards

Featured Products
Certified Reference Materials (CRMs) Qty Cat. No.
CRM matrix standards
Ordering information for matrix standards varies by country.
Please visit sigma-aldrich.com/rtccrm for details or contact your local Sigma-Aldrich office.
PAHs, PCBs & Pesticides on Fresh Water Sediment 50 g CNS391
Pesticides - Loamy Sand 1 50 g CRM846
PAHs, PCBs & Pesticides on Sewage Sludge 50 g CNS312
PCBs & PDBEs on Fresh Water Sandy Loam Sediment 50 g CNS329
Pesticides - Loam 1 50 g CNS329
CRM Neats
Atrazine, CRM, TraceCERT 50 mg 90935
Biphenyl, CRM, TraceCERT 100 mg 96996
Chlorpyrifos, CRM, TraceCERT 100 mg 94114
Cypermethrin, CRM, TraceCERT 50 mg 51991
Diazinon, CRM, TraceCERT 50 mg 68486
Deltamethrin, CRM, TraceCERT 50 mg 05995
Fipronil, CRM, TraceCERT 50 mg 16785
Malathion, CRM, TraceCERT 50 mg 91481
ProChloraz, CRM, TraceCERT 50 mg 64947
NEATs (non-certified)
Atrazine, PESTANAL 250 mg 45330
Azadirachtin (technical mixture) 10 mg PS2075
À-Cyhalothrin PESTANAL 100 mg 31058
Cypermethrin (mixture of isomers), PESTANAL 100 mg 36128
o,p'-DDE 50 mg PS695
Glufosinate ammonium, PESTANAL 100 mg 45520
Glyphosate, PESTANAL 250 mg 45521
Heptachlor 100 mg PS78
Imidacloprid, PESTANAL 100 mg 31058
Oxydemeton-methyl 50 mg PS641
Paraquat dichloride, PESTANAL 100 mg 36541
Paraoxon-ethyl PESTANAL 100 mg 36186
Thiacloprid 100 mg 37905
Mixtures
DDT – Endrin Mixture
500 µg/mL each component in methanol
1 mL 48282
Triazines Mixture
100 µg/mL each component in methanol
Ametryn
Atrazine
Prometon
Prometryn
Propazine
Simazine
Terbutryn
 
1 mL
 
48392
CLP Organochlorine Pesticide Mix
2000 µg/mL each component in hexane:toluene (1:1)
Aldrin
α-BHC
β-BHC
Lindane
δ-BHC
α-Chlordane
γ-Chlordane
4,4'-DDD
4,4'-DDE
4,4'-DDT
Dieldrin
α-Endosulfan
β-Endosulfan
Endosulfan sulfate
Endrin
Endrin aldehyde
Endrin ketone
Heptachlor
Heptachlor epoxide
Heptachlor epoxide isomer B
Methyoxychlor
 
1 mL
 
47426-U
EPA 8270 Organophosphorus Pesticide Mix 2
2000 µg/mL in methylene chloride
Dimethoate
Disulfoton
Famphur
Parathion
Parathion-methyl
Phorate
Sulfotep
Thionazin
Triethyl thiophosphate
 
1 mL
 
47908
EPA 8081 Pesticide Standard Mix
200 µg/mL each component in hexane:toluene (1:1)
Aldrin
α-BHC
β-BHC
Lindane
δ-BHC
α-Chlordane
γ-Chlordane
4,4’-DDD
4,4'-DDE
4,4'-DDT
Decachlorobiphenyl
Dieldrin
α-Endosulfan
β-Endosulfan
Endosulfan sulfate
Endrin

Endrin aldehyde
Endrin ketone
Heptachlor
Heptachlor exo-epoxide
Methyoxychlor
2,4,5,6-Tetrachloro-m-xylene
 
1 mL
 
46845-U
EPA 8081 Pesticide Surrogate Spike Mix
200 µg/mL each component in acetone
Decachlorobiphenyl
2,4,5,6-Tetrachloro-m-xylene
 
1 mL
 
48460
OP Pesticide Mix
100 µg/mL each component in hexane
Carbophenothion
Ethion
Malathion
Parathion
 
 
1 mL
 
861237
OP Pesticide Mix 2
1000 µg/mL each component in acetone
Alachlor
Atrazine
Bromacil
Butachlor
Metolachlor
Prometon
Simazine
 
1 mL
 
861283
Pesticide Standard 17 Solution, PESTANAL
10 ng/µL each component in acetonitrile
Atrazine
Atrazine-desethyl
Cyanazine
Sebuthylazine
Simazine
Terbuthylazine
Hexazinone
Chlortoluron
Diuron
Isoproturon
Linuron
Methabenzthiazuron
Metobromuron
Metoxuron
Monolinuron
Metazoachlor
Metolachlor
 
1 mL
 
36978
 
Proficiency Testing (PT) Samples Qty Cat. No.
Ordering information for PT products varies by country.
Please visit sigma-aldrich.com/rtccrm for details or contact your local Sigma-Aldrich office.
Water Pollution
Organophosphorus Pesticides – WP 1 x 2 mL PE1161
Organophosphorus Pesticides (Low Level) - WP 1 x 2 mL PE1377
Pesticides 1- WP 1 x 2 mL PE1280
Pesticides 2- WP 1 x 2 mL PE1201
Water Supply
Carbamate Pesticides - WS 1 x 2 mL PE1507
Organonitrogen Pesticides – WS 1 x 2 mL PE1400
Soil
Chlorinated Pesticides in Soil 50 g SPE009
Organophosphorus Pesticides 50 g SPE021