Which models are included in the post-column derivatives of JOSVOK?

The post-column derivatization devices currently developed by JOSVOK (Tianjin) Technology Development Co., Ltd. include PCR-1500I single-pump SLR, PCR-1500II double-pump double-reverse derivatization system, and PHRE-15 photochemical derivatizer.

What are the national standards for carbamate detection corresponding to post-column derivatization?

GB23200.112-2018

HJ 960-2018

How does post-column derivatization of carbamate pesticides work?

Because the structure of carbamate pesticides all contain N-methylcarbamoyl group. The carbamate separated by the chromatographic column is first hydrolyzed under the action of NaOH at 100°C to release alcohol, carbonate and methylamine. Subsequently, in the secondary post-column reaction, methylamine reacts with o-phthalaldehyde (OPA and 2-mercaptoethanol) to generate 1-methyl-2-vermidol compounds with strong fluorescence absorption, which are detected by a fluorescence detector and have Very low detection limit, meeting the requirements of residue analysis methods.

What are the post-column conditions for carbamate analysis?

Derivatization Reagent 1: Hydrolysis Derivatization Reagent, 1000ml

Derivatization reagent 2: 100mg OPA, 2g Thiofluor dissolved in 950mL

Post-column reactor temperature: 100°C, flow rate of derivatization reagent 0.5mL

Reactor temperature after secondary column: ambient temperature, flow rate of derivatization reagent: 0.3mL/min

Detection conditions: Fluorescence detector: EX330nm, Em465nm

Chromatographic column: 4.6×250mm, C18, 5um

What are the considerations in carbamate analysis?

It is not recommended for users to prepare their own OPA and hydrolysis reagents because it is difficult to obtain NaOH of sufficient purity, in addition sodium borate (any grade) contains excess heavy metals and insolubles, which will eventually settle in the reactor and flow cell. It is recommended to use the special carbamate derivative solution prepared by Zhongshi Walker, which not only saves time and effort, but also ensures accurate and reliable detection data.