57000 F Amino Acids and Acylcarnitines from Dried Blood/Non Derivatised

MassChrom® Amino Acids and Acylcarnitines from Dried Blood/Non Derivatised - LC-MS/MS

Order no.: 57000/F
960 Tests
  • Acylcarnitines & free carnitine
  • Amino acids

All required and isotope labelled standards included
Dried blood spot controls included
Direct sample injection without derivatisation
High selectivity and sensitivity by MS/MS detection

Description

Clinical relevance

Newborn screening aims to detect congenital metabolic disorders early on before they can cause harm to the organism. Included in these diseases are defects of amino acid metabolism such as phenylketonuria (PKU) and maple syrup urine disease (MSUD), defects of fatty acid metabolism and organic acidurias (isovaleric acidemia). If these diseases are not diagnosed, the metabolic disorders can already lead to severe irreversible harm to the newborns within their first few days of life.

Mass spectrometry is the method of choice for diagnostic testing: it enables to check for a broad range of metabolic defects in a single run. An HPLC column is not required due to the high selectivity of LC-MS/MS. This makes it possible to achieve a very precise quantification in a very short analysis time of less than 2 minutes.

 

Product advantages

  • Direct injection without derivatisation
  • Multiple diagnoses in a single run
  • High selectivity and sensitivity by MS/MS detection
  • Dried blood spot controls included

 

This Chromsystems kit allows the very fast and semiquantitative determination of amino acids and acylcarnitines from dried blood spot (DBS) samples as part of newborn screening using tandem mass spectrometry. Sample preparation can be performed in less than 2 hours and is based on effective extraction of the analytes from the filter card. 27 stable isotope-labelled internal standards for calibration and measurement ensure reproducible quantification of the analytes.

Compared with the method that uses derivatisation (order no. 55000), this direct injection method is characterised by a more efficient sample preparation and an analysis in MRM mode that results in highest precision of results. However, this method has a slightly lower sensitivity and shows potential interferences from isobaric compounds of the acylcarnitines, such as C5DC and C6OH.

Chromatogram

Technical Data

Method of Analysis

LC-MS/MS

Number of Tests

960

Parameter

Acylcarnitines & free carnitine, Amino acids

Analysis Time

< 2 min

Limit of quantification

Amino acids: 2.5-30 µmol/l
(Acyl-)carnitines: 0.1-1.6 µmol/l

Linearity

Amino acids: 2000-2400 µmol/l
(Acyl-)carnitines: 25-200 µmol/l

Recovery

Amino acids: 64-94 %; (Acyl-)carnitines: 63-102 %

Intraassay

Amino acids: CV = 2-11 %
(Acyl-)carnitines: CV = 3-12 %

Interassay

Amino acids: CV = 3.5-18 %
(Acyl-)carnitines: CV= 4.8-14 %

Cutoff thresholds

Amino acids: ca. 30 to 1000 µmol/l
free carnitine: ca. 55 µmol/l
Acylcarnitines: ca. 0.2 to 10 µmol/l

Information

Mass transitions of analytes and internal standards

Amino acids MRM
Alanine 90 > 44
Alanine-D4 94 > 48
Arginine 175 > 70
Arginine-D7 182 > 77
Aspartic acid 134 > 116
Aspartic acid-D3 137 > 119
Citrulline 176 > 113
Citrulline-D2 178 > 115
Glutamic acid 148 > 130
Glutamic acid-D5 153 > 135
Glycine 76 > 30
Glycine-13C2-15N 79 > 32
Leucine 132 > 86
Leucine-D3 135 > 89
Methionine 150 > 133
Methionine-D3 153 > 136
Ornithine 133 > 70
Ornithine-D6 139 > 76
Phenylalanine 166 > 120
Phenylalanine-D5 171 > 125
Proline 116 > 70
Proline-D7 123 > 77
Tyrosine 182 > 136
Tyrosine-D4 186 > 140
Valine 118 > 72
Valine-D8 126 > 80
   
(Acyl-)carnitines MRM
Carnitine 162 >85
Carnitine-D9 171 > 85
C2-Carnitine 204 > 85
C2-Carnitine-D3 207 > 85
C3-Carnitine 218 > 85
C3-Carnitine-D3 221 > 85
C4-Carnitine 232 > 85
C4-Carnitine-D3 235 > 85
C5-Carnitine 246 > 85
C5-Carnitine-D9 255 > 85
C5DC-Carnitine 276 > 85
C5DC-Carnitine-D6 282 > 85
C6-Carnitine 260 > 85
C6-Carnitine-D3 263 > 85
C8-Carnitine 288 > 85
C8-Carnitine-D3 291 > 85
C10-Carnitine 316 > 85
C10-Carnitine-D3 319 > 85
C12-Carnitine 344 > 85
C12-Carnitine-D3 347 > 85
C14-Carnitine 428 > 85
C14-Carnitine-D3 375 > 85
C16-Carnitine 400 > 85
C16-Carnitine-D3 403 > 85
C18-Carnitine 428 > 85
C18-Carnitine-D3 431 > 85

Flow rate

20 to 600 µl/min

Specimen

Dried blood

Pre-analytic Treatment

Specimen

  • Take blood from the heel of the newborn onto a suitable filter card. Dry 4 hours at ambient temperature.

Time of sample drawing

  • 48th to 72nd hour of life.

Sample Preparation

  • Punch 3 mm dried blood spot disk out of the filter card into a well plate.
  • Add 100 µl Internal Standard, agitate for 20 min.
  • Inject 10 µl of the extract into the LC-MS/MS system.

Sample Stability

21 days at +2 to +25 °C. For longer storage the samples should be frozen with humidity excluded (below -18 °C). Avoid temperatures above 37 °C.

Injection Volume

10 µl

Autosampler rinsing solution

Rinsing Solution (57007)

MS/MS-Mode

MRM

Additional Info

No HPLC column is required.

Please note

The freely available information on this website, in particular on the sample preparation, are not sufficient to work with our products. Please read instructions and warning notices on products and/or instruction manuals.

Kit Components

Controls

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