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Back to the forum  Query: 2018-04-23 00:15 CEST (UTC+2h)
 
Obinoscopy
Junior

Nigeria,
2018-04-15 02:19
(edited by Obinoscopy on 2018-04-15 02:44)

Posting: # 18682
Views: 415
 

 Zero Sample Preparation [Bioanalytics]

Hi guys,

How is the zero sample prepared? I know the blank sample is a biological matrix without the analyte and its internal standard. I also know the non zero samples are biological matrix spiked with a particular concentration of the analyte and same concentration of the internal standard.

The zero sample is a biological matrix spiked with the internal standard only. My question is this: What is the actual concentration of the internal standard that should be used to prepare the zero sample?

Obinoscopy

Scopy
Ohlbe
Hero

France,
2018-04-16 10:38

@ Obinoscopy
Posting: # 18685
Views: 337
 

 Zero Sample Preparation

Dear Obinoscopy,

» My question is this: What is the actual concentration of the internal standard that should be used to prepare the zero sample?

Simple: the same concentration as in all other samples. Just spike a blank with the same volume of your IS working solution as all CC, QC and subject samples.

Regards
Ohlbe
Obinoscopy
Junior

Nigeria,
2018-04-20 08:17

@ Ohlbe
Posting: # 18705
Views: 195
 

 Zero Sample Preparation

» Simple: the same concentration as in all other samples. Just spike a blank with the same volume of your IS working solution as all CC, QC and subject samples.

Thanks for this. So my follow up question is this: What's the compositional or structural difference between a CC sample and BC sample. I know they have different functions during both bioanalytical validation and bioanalysis.

Scopy
Ohlbe
Hero

France,
2018-04-20 10:15

@ Obinoscopy
Posting: # 18706
Views: 185
 

 Zero Sample Preparation

Dear Obinoscopy,

» What's the compositional or structural difference between a CC sample and BC sample.

Sorry but BC is not an abbreviation I'm familiar with. What do you mean by BC ?

Regards
Ohlbe
Obinoscopy
Junior

Nigeria,
2018-04-20 16:03

@ Ohlbe
Posting: # 18709
Views: 172
 

 Zero Sample Preparation

» Sorry but BC is not an abbreviation I'm familiar with. What do you mean by BC ?»

Oops, sorry a typo on my end. I meant to write QC and not BC

Scopy
Ohlbe
Hero

France,
2018-04-20 16:21

@ Obinoscopy
Posting: # 18711
Views: 167
 

 Zero Sample Preparation

Dear Scopy,

» Oops, sorry a typo on my end. I meant to write QC and not BC

OK, then I know what it is :-)

» So my follow up question is this: What's the compositional or structural difference between a CC sample and BC sample.

None. Both are blank matrix spiked with known concentrations of analyte, then with IS when they are processed. The concentrations of the CC samples are established based on the expected range of concentrations to be measured; the concentrations of the QC samples are derived from that (LQC # 3 times the LLOQ, HQC at least 75 % of the ULOQ, MQC somewhere mid-range - the EMA guideline says 30-50 % of the range).

Regards
Ohlbe
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